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Author Huygh, S.; Bogaerts, A.; Neyts, E.C. pdf  url
doi  openurl
  Title How Oxygen Vacancies Activate CO2 Dissociation on TiO2 Anatase (001) Type A1 Journal article
  Year 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 120 Issue 120 Pages 21659-21669  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The adsorption, dissociation, and diffusion of CO2 on the anatase (001) surface was studied using DFT by means of the generalized gradient approximation using the Perdew−Burcke−Ernzerhof (PBE)-functional and applying corrections for long-range dispersion interactions. Different stable adsorption configurations were identified for the fully oxidized surface. The most stable adsorption configuration is the monodentated carbonate-like structure. Small energy barriers were identified for the conversion of a physisorbed to a chemisorbed configuration.

CO2 dissociation is found to be unfeasible on the stoichiometric surface. The introduction of oxygen vacancy defects gives rise to new highly stable adsorption configurations with a stronger activation of the C−O bonds. This leads to the possibility of exothermic dissociation of CO2 with barriers up to 22.2 kcal/mol,

corresponding to chemical lifetimes of less than 4 s at 300 K. These reactions cause a CO molecule to be formed, which will easily desorb, and the reduced surface to become oxidized. It is clear that oxygen vacancy defects play a key role in the catalytic activity of an anatase (001) surface. Oxygen vacancies play an important role in the dissociation of CO2 on the anatase (001) surface, and will play a significant role in complex problems, such as the catalytic conversion of CO2 to value-added chemicals.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000384626800055 Publication Date 2016-09-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 49 Open Access  
  Notes Stijn Huygh is funded as an aspirant of the Research Foundation Flanders (FWO, project number 11C0115N). This work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the UAntwerpen. Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @ c:irua:136164 Serial 4291  
Permanent link to this record
 

 
Author Zhang, Y.-R.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Influence of the Material Dielectric Constant on Plasma Generation inside Catalyst Pores Type A1 Journal article
  Year 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 120 Issue 120 Pages 25923-25934  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma catalysis is gaining increasing interest for various environmental applications, but the crucial question is whether plasma can be created inside catalyst pores and under which conditions. In practice, various catalytic support materials are used, with various dielectric constants. We investigate here the influence of the dielectric constant on the plasma properties inside catalyst pores and in the sheath in front of the pores, for various pore sizes. The calculations are performed by a two-dimensional fluid model for an atmospheric pressure dielectric barrier discharge in helium. The electron impact ionization rate, electron temperature, electron and ion density, as well as the potential distribution and surface charge density, are analyzed for a better understanding of the discharge behavior inside catalyst pores. The results indicate that, in a 100 μm pore, the electron impact ionization in the pore, which is characteristic for the plasma generation inside the pore, is greatly enhanced for dielectric constants below 300. Smaller pore sizes only yield enhanced ionization for smaller dielectric constants, i.e., up to εr = 200, 150, and 50 for pore sizes of 50, 30, and 10 μm. Thus, the most common catalyst supports, i.e., Al2O3 and SiO2, which have dielectric constants around εr = 8−11 and 4.2, respectively, should allow more easily that microdischarges can be formed inside catalyst pores, even for smaller pore sizes. On the other hand, ferroelectric materials with dielectric constants above 300 never seem to yield plasma enhancement inside catalyst pores, not even for 100 μm pore sizes. Furthermore, it is clear that the dielectric constant of the material has a large effect on the extent of plasma enhancement inside the catalyst pores, especially in the range between εr = 4 and εr = 200. The obtained results are explained in detail based on the surface charge density at the pore walls,

and the potential distribution and electron temperature inside and above the pores. The results obtained with this model are

important for plasma catalysis, as the production plasma species in catalyst pores might affect the catalyst properties, and thus

improve the applications of plasma catalysis.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000388429100029 Publication Date 2016-11-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 34 Open Access  
  Notes This work was supported by the Fund for Scientific Research Flanders (FWO) (Grant G.0217.14N), the National Natural Science Foundation of China (Grant 11405019), and the China Postdoctoral Science Foundation (Grant 2015T80244). This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the University of Antwerp. Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @ c:irua:138602 Serial 4319  
Permanent link to this record
 

 
Author De Bie, C.; van Dijk, J.; Bogaerts, A. pdf  url
doi  openurl
  Title CO2Hydrogenation in a Dielectric Barrier Discharge Plasma Revealed Type A1 Journal article
  Year 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 120 Issue 120 Pages 25210-25224  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The hydrogenation of carbon dioxide in a dielectric barrier discharge plasma is studied with a one-dimensional fluid model. The spatially averaged densities of the most important end products formed in the CO2/H2 mixture are determined as a function of the initial gas mixing ratio. CO and H2O are found to be present at the highest densities and to a lower content also CH4, C2H6, CH2O, CH3OH, O2, and some other higher hydrocarbons and oxygenates. The main underlying reaction

pathways for the conversion of the inlet gases and the formation of CO, CH4, CH2O, and CH3OH are pointed out for various gas mixing ratios. The CO2 conversion and the production of value added products is found to be quite low, also in comparison to a CO2/CH4 mixture, and this can be explained by the model.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000387737900007 Publication Date 2016-11-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 16 Open Access  
  Notes Federaal Wetenschapsbeleid; Fonds Wetenschappelijk Onderzoek; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @ c:irua:140082 c:irua:139167 Serial 4414  
Permanent link to this record
 

 
Author Verlackt, C.C.W.; Van Boxem, W.; Dewaele, D.; Lemière, F.; Sobott, F.; Benedikt, J.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Mechanisms of Peptide Oxidation by Hydroxyl Radicals: Insight at the Molecular Scale Type A1 Journal article
  Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 121 Issue 121 Pages 5787-5799  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Molecular dynamics (MD) simulations were performed to provide atomic scale insight in the initial interaction between hydroxyl radicals (OH) and peptide systems in solution. These OH radicals are representative reactive oxygen species produced by cold atmospheric plasmas. The use of plasma for biomedical applications is gaining increasing interest, but the fundamental mechanisms behind the plasma modifications still remain largely elusive. This study helps to gain more insight in the underlying mechanisms of plasma medicine but is also more generally applicable to peptide oxidation, of interest for other applications. Combining both reactive and nonreactive MD simulations, we are able to elucidate the reactivity of the amino acids inside the peptide systems and their effect on their structure up to 1 μs. Additionally, experiments were performed, treating the simulated peptides with a plasma jet. The computational results presented here correlate well with the obtained experimental data and highlight the importance of the chemical environment for the reactivity of the individual amino acids, so that specific amino acids are attacked in higher numbers than expected. Furthermore, the long time scale simulations suggest that a single oxidation has an effect on the 3D conformation due to an increase in hydrophilicity and intra- and intermolecular interactions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000396969900037 Publication Date 2017-03-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 5 Open Access OpenAccess  
  Notes Fonds Wetenschappelijk Onderzoek, G012413N ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @ c:irua:142202 Serial 4537  
Permanent link to this record
 

 
Author Berthelot, A.; Bogaerts, A. pdf  url
doi  openurl
  Title Modeling of CO2Splitting in a Microwave Plasma: How to Improve the Conversion and Energy Efficiency Type A1 Journal article
  Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 121 Issue 121 Pages 8236-8251  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Microwave plasmas are one of the most promising techniques for CO2 conversion into value-added chemicals and fuels since they are very energy efficient. Nevertheless, experiments show that this high energy efficiency is only reached at low pressures and significantly drops toward atmospheric pressure, which is a clear limitation for industrial applications. In this paper, we use a zerodimensional reaction kinetics model to simulate a CO2 microwave plasma in a pressure range from 50 mbar to 1 bar, in order to evaluate the reasons for this decrease in energy efficiency at atmospheric pressure. The code includes a detailed description of the vibrational kinetics of CO2, CO, and O2 as well as the energy exchanges between them because the vibrational kinetics is known to be crucial for energy efficient CO2 splitting. First, we use a self-consistent gas temperature calculation in order to assess the key performance indicators for CO2 splitting, i.e., the CO2 conversion and corresponding energy efficiency. Our results indicate that lower pressures and higher power densities lead to more vibrational excitation, which is beneficial for the conversion. We also demonstrate the key role of the gas temperature. The model predicts the highest conversion and energy efficiencies at pressures around 300 mbar, which is in agreement with experiments from the literature. We also show the beneficial aspect of fast gas cooling in the afterglow at high pressure. In a second step, we study in more detail the effects of pressure, gas temperature, and power density on the vibrational distribution function and on the dissociation and recombination mechanisms of CO2, which define the CO2 splitting efficiency. This study allows us to identify the limiting factors of CO2 conversion and to propose potential solutions to improve the process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000400039300002 Publication Date 2017-04-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 47 Open Access OpenAccess  
  Notes Federaal Wetenschapsbeleid; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @ c:irua:142809 Serial 4567  
Permanent link to this record
 

 
Author Grubova, I.Y.; Surmeneva, M.A.; Huygh, S.; Surmenev, R.A.; Neyts, E.C. doi  openurl
  Title Density functional theory study of interface interactions in hydroxyapatite/rutile composites for biomedical applications Type A1 Journal article
  Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 121 Issue 29 Pages 15687-15695  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract To gain insight into the nature of the adhesion mechanism between hydroxyapatite (HA) and rutile (rTiO(2)), the mutual affinity between their surfaces was systematically studied using density functional theory (DFT). We calculated both bulk and surface properties of HA and rTiO(2), and explored the interfacial bonding mechanism of amorphous HA (aHA) surface onto amorphous as well as stoichiometric and nonstoichiometric crystalline rTiO(2). Formation energies of bridging and subbridging oxygen vacancies considered in the rTiO(2)(110) surface were evaluated and compared with other theoretical and experimental results. The interfacial interaction was evaluated through the work of adhesion. For the aHA/rTiO(2)(110) interfaces, the work of adhesion is found to depend strongly on the chemical environment of the rTiO(2)(110) surface. Electronic analysis indicates that the charge transfer is very small in the case of interface formation between aHA and crystalline rTiO(2)(110). In contrast, significant charge transfer occurs between aHA and amorphous rTiO(2) (aTiO(2)) slabs during the formation of the interface. Charge density difference (CDD) analysis indicates that the dominant interactions in the interface have significant covalent character, and in particular the Ti-O and Ca-O bonds. Thus, the obtained results reveal that the aHA/aTiO(2) interface shows a more preferable interaction and is thermodynamically more stable than other interfaces. These results are particularly important for improving the long-term stability of HA-based implants.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000406726200022 Publication Date 2017-06-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 5 Open Access Not_Open_Access  
  Notes Approved (up) Most recent IF: 4.536  
  Call Number UA @ lucian @ c:irua:145195 Serial 4715  
Permanent link to this record
 

 
Author Vets, C.; Neyts, E.C. doi  openurl
  Title Stabilities of bimetallic nanoparticles for chirality-selective carbon nanotube growth and the effect of carbon interstitials Type A1 Journal article
  Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 121 Issue 28 Pages 15430-15436  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Bimetallic nanoparticles play a crucial role in various applications. A better understanding of their properties would facilitate these applications and possibly even enable chirality-specific growth of carbon nanotubes (CNTs). We here examine the stabilities of NiFe, NiGa, and FeGa nanoparticles and the effect of carbon dissolved in NiFe nanoparticles through density functional theory (DFT) calculations and Born Oppenheimer molecular dynamics (BOMD) simulations. We establish that nanoparticles with more Fe in the core and more Ga on the surface are more stable and compare these results with well-known properties such as surface energy and atom size. Furthermore, we find that the nanoparticles become more stable with increasing carbon content, both at 0 K and at 700 K. These results provide a basis for further research into the chirality-specific growth of CNT's.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000406355700050 Publication Date 2017-06-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 2 Open Access Not_Open_Access  
  Notes Approved (up) Most recent IF: 4.536  
  Call Number UA @ lucian @ c:irua:145206 Serial 4725  
Permanent link to this record
 

 
Author Trenchev, G.; Kolev, S.; Wang, W.; Ramakers, M.; Bogaerts, A. pdf  url
doi  openurl
  Title CO2Conversion in a Gliding Arc Plasmatron: Multidimensional Modeling for Improved Efficiency Type A1 Journal article
  Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 121 Issue 44 Pages 24470-24479  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The gliding arc plasmatron (GAP) is a highly efficient atmospheric plasma source, which is very promising for CO2 conversion applications. To understand its operation principles and to improve its application, we present here comprehensive modeling results, obtained by means of computational fluid dynamics simulations and plasma modeling. Because of the complexity of the CO2 plasma, a full 3D plasma model would be computationally impractical. Therefore, we combine a 3D turbulent gas flow model with a 2D plasma and gas heating model in order to calculate the plasma parameters and CO2 conversion characteristics. In addition, a complete 3D gas flow and plasma model with simplified argon chemistry is used to evaluate the gliding arc evolution in space and time. The calculated values are compared with experimental data from literature as much as possible in order to validate the model. The insights obtained in this study are very helpful for improving the application of CO2 conversion, as they allow us to identify the limiting factors in the performance, based on which solutions can be provided on how to further improve the capabilities of CO2 conversion in the GAP.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000415140400014 Publication Date 2017-11-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited Open Access OpenAccess  
  Notes H2020 Marie Sklodowska-Curie Actions, 657304 ; Fonds Wetenschappelijk Onderzoek, 11U5316N G038316N ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:147193 Serial 4765  
Permanent link to this record
 

 
Author Heijkers, S.; Bogaerts, A. pdf  url
doi  openurl
  Title CO2Conversion in a Gliding Arc Plasmatron: Elucidating the Chemistry through Kinetic Modeling Type A1 Journal article
  Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 121 Issue 41 Pages 22644-22655  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract By means of chemical kinetics modeling, it is possible to elucidate the main dissociation mechanisms of CO2 in a gliding arc plasmatron (GAP). We obtain good agreement between the calculated and experimental conversions and energy efficiencies, indicating that the model can indeed be used to study the underlying mechanisms. The calculations predict that vibration-induced dissociation is the main dissociation mechanism of CO2, but it occurs mainly from the lowest vibrational levels because of fast thermalization of the vibrational distribution. Based on these findings, we propose ideas for improving the performance of the GAP, but testing of these ideas in the simulations reveals that they do not always lead to significant enhancement, because of other side effects, thus illustrating the complexity of the process. Nevertheless, the model allows more insight into the underlying mechanisms to be obtained and limitations to be identified.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000413617900007 Publication Date 2017-10-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 6 Open Access OpenAccess  
  Notes Federaal Wetenschapsbeleid, IAP/7 ; Fonds Wetenschappelijk Onderzoek, G.0383.16N ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:147436 Serial 4801  
Permanent link to this record
 

 
Author Wang, W.; Snoeckx, R.; Zhang, X.; Cha, M.S.; Bogaerts, A. pdf  url
doi  openurl
  Title Modeling Plasma-based CO2and CH4Conversion in Mixtures with N2, O2, and H2O: The Bigger Plasma Chemistry Picture Type A1 Journal article
  Year 2018 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 122 Issue 16 Pages 8704-8723  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Because of the unique properties of plasma technology, its use in gas conversion applications is gaining significant interest around the globe. Plasma-based CO2 and CH4 conversion has become a major research area. Many investigations have already been performed regarding the single-component gases, that is, CO2 splitting and CH4 reforming, as well as for two-component mixtures, that is, dry reforming of methane

(CO2/CH4), partial oxidation of methane (CH4/O2), artificial photosynthesis (CO2/H2O), CO2 hydrogenation (CO2/H2), and even first steps toward the influence of N2 impurities have been taken, that is, CO2/N2 and CH4/N2. In this Feature Article we briefly discuss the advances made in literature for these different steps from a plasma chemistry modeling point of view. Subsequently, we present a comprehensive plasma chemistry set, combining the knowledge gathered in this field so far and supported with extensive experimental data. This set can be used for chemical kinetics plasma modeling for all possible combinations of CO2, CH4, N2, O2, and H2O to investigate the bigger picture of the underlying plasmachemical pathways for these mixtures in a dielectric barrier discharge plasma. This is extremely valuable

for the optimization of existing plasma-based CO2 conversion and CH4 reforming processes as well as for investigating the influence of N2, O2, and H2O on these processes and even to support plasma-based multireforming processes.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000431151200002 Publication Date 2018-04-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 28 Open Access OpenAccess  
  Notes Federaal Wetenschapsbeleid, IAP/7 ; King Abdullah University of Science and Technology; H2020 Marie Sklodowska-Curie Actions, 657304 ; Fonds Wetenschappelijk Onderzoek, G.0217.14N G.0383.16N G.0254.14N ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:150969 Serial 4922  
Permanent link to this record
 

 
Author Huygh, S.; Bogaerts, A.; Bal, K.M.; Neyts, E.C. pdf  url
doi  openurl
  Title High Coke Resistance of a TiO2Anatase (001) Catalyst Surface during Dry Reforming of Methane Type A1 Journal Article
  Year 2018 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C  
  Volume 122 Issue 17 Pages 9389-9396  
  Keywords A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;  
  Abstract The resistance of a TiO2 anatase (001) surface to coke formation was studied in the context of dry reforming of methane using density functional theory (DFT) calculations. As carbon atoms act as precursors for coke formation, the resistance to coke formation can be measured by the carbon coverage of the surface. This is related to the stability of different CHx (x = 0−3) species and their rate of hydrogenation and dehydrogenation on the TiO2 surface. Therefore, we studied the reaction mechanisms and their corresponding rates as a function of the temperature for the dehydrogenation of the species on the surface. We found that the stabilities of C and CH are significantly lower than those of CH3 and CH2. The hydrogenation rates of the different species are significantly higher than the dehydrogenation rates in a temperature range of 300−1000 K. Furthermore, we found that dehydrogenation of CH3, CH2, and CH will only occur at appreciable rates starting from 600, 900, and 900 K, respectively. On the basis of these results, it is clear that the anatase (001) surface has a high coke resistance, and it is thus not likely that the surface will become poisoned by coke during dry reforming of methane. As the rate limiting step in dry reforming is the dissociative adsorption of CH4, we studied an alternative approach to thermal catalysis. We found that the temperature threshold for dry reforming is at least 700 K. This threshold temperature may be lowered by the use of plasma-catalysis, where the appreciable rates of adsorption of plasma-generated CHx radicals result in bypassing the rate limiting step of the reaction.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000431723700014 Publication Date 2018-05-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 1 Open Access OpenAccess  
  Notes Federaal Wetenschapsbeleid, IAP/7 ; Fonds Wetenschappelijk Onderzoek, G.0217.14N ; Onderzoeksfonds, Universiteit Antwerpen, 32249 ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:151529c:irua:152816 Serial 5000  
Permanent link to this record
 

 
Author Vermeiren, V.; Bogaerts, A. pdf  url
doi  openurl
  Title Supersonic Microwave Plasma: Potential and Limitations for Energy-Efficient CO2Conversion Type A1 Journal Article
  Year 2018 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C  
  Volume 122 Issue 45 Pages 25869-25881  
  Keywords A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;  
  Abstract Supersonic flows provide a high thermodynamic

nonequilibrium, which is crucial for energy-efficient conversion of

CO 2 in microwave plasmas and are therefore of great interest.

However, the effect of the flow on the chemical reactions is poorly

understood. In this work, we present a combined flow and plasma

chemical kinetics model of a microwave CO 2 plasma in a Laval

nozzle setup. The effects of the flow field on the different dissociation

and recombination mechanisms, the vibrational distribution, and the

vibrational transfer mechanism are discussed. In addition, the effect

of experimental parameters, like position of power deposition, outlet

pressure, and specific energy input, on the CO 2 conversion and

energy efficiency is examined. The short residence time of the gas in

the plasma region, the shockwave, and the maximum critical heat,

and thus power, that can be added to the flow to avoid thermal

choking are the main obstacles to reaching high energy efficiencies.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000451101400016 Publication Date 2018-11-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 5 Open Access Not_Open_Access  
  Notes Fonds Wetenschappelijk Onderzoek, G.0383.16N ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:155412 Serial 5070  
Permanent link to this record
 

 
Author Bal, K.M.; Neyts, E.C. pdf  url
doi  openurl
  Title Overcoming Old Scaling Relations and Establishing New Correlations in Catalytic Surface Chemistry: Combined Effect of Charging and Doping Type A1 Journal article
  Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 123 Issue 10 Pages 6141-6147  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Optimization of catalytic materials for a given application is greatly constrained by linear scaling relations. Recently, however, it has been demonstrated that it is possible to reversibly modulate the chemisorption of molecules on nanomaterials by charging (i.e., injection or removal of electrons) and hence reversibly and selectively modify catalytic activity beyond structure−activity correlations. The fundamental physical relation between the properties of the material, the charging process, and the chemisorption energy, however, remains unclear, and a systematic exploration and optimization of charge-switchable sorbent materials is not yet possible. Using hybrid DFT calculations of CO2 chemisorption on hexagonal boron nitride nanosheets with several types of defects and dopants, we here reveal the existence of fundamental correlations between the electron affinity of a material and charge-induced chemisorption, show how defect engineering can be used to modulate the strength and efficiency of the adsorption process, and demonstrate that excess electrons stabilize many topological defects. We then show how these insights could be exploited in the development of new electrocatalytic materials and the synthesis of doped nanomaterials. Moreover, we demonstrate that calculated chemical properties of charged materials are highly sensitive to the employed computational methodology because of the self-interaction error, which underlines the theoretical challenge posed by such systems.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000461537400035 Publication Date 2019-03-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 5 Open Access Not_Open_Access: Available from 21.02.2020  
  Notes Fonds Wetenschappelijk Onderzoek, 11V8915N ; Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @UA @ admin @ c:irua:158117 Serial 5160  
Permanent link to this record
 

 
Author Heijkers, S.; Martini, L.M.; Dilecce, G.; Tosi, P.; Bogaerts, A. pdf  url
doi  openurl
  Title Nanosecond Pulsed Discharge for CO2Conversion: Kinetic Modeling To Elucidate the Chemistry and Improve the Performance Type A1 Journal article
  Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 123 Issue 19 Pages 12104-12116  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract We study the mechanisms of CO2 conversion in a nanosecond repetitively pulsed (NRP) discharge, by means of a chemical kinetics model. The calculated conversions and energy efficiencies are in reasonable agreement with experimental results over a wide range of specific energy input values, and the same applies to the evolution of gas temperature and CO2 conversion as a function of time in the afterglow, indicating that our model provides a realistic picture of the underlying mechanisms in the NRP discharge and can be used to identify its limitations and thus to suggest further improvements. Our model predicts that vibrational excitation is very important in the NRP discharge, explaining why this type of plasma yields energy-efficient CO2 conversion. A significant part of the CO2 dissociation occurs by electronic excitation from the lower vibrational levels toward repulsive electronic states, thus resulting in dissociation. However, vibration−translation (VT) relaxation (depopulating the higher vibrational levels) and CO + O recombination (CO + O + M → CO2 + M), as well as mixing of the converted gas with fresh gas entering the plasma in between the pulses, are limiting factors for the conversion and energy efficiency. Our model predicts that extra cooling, slowing down the rate of VT relaxation and of the above recombination reaction, thus enhancing the contribution of the highest vibrational levels to the overall CO2 dissociation, can further improve the performance of the NRP discharge for energy-efficient CO2 conversion.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000468368800009 Publication Date 2019-05-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 4 Open Access Not_Open_Access: Available from 26.04.2020  
  Notes Fonds Wetenschappelijk Onderzoek, G.0383.16N ; The authors acknowledge financial support from the Fund for Scientific Research, Flanders (FWO; Grant no. G.0383.16N). Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @UA @ admin @ c:irua:159976 Serial 5174  
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Author Jafarzadeh, A.; Bal, K.M.; Bogaerts, A.; Neyts, E.C. pdf  url
doi  openurl
  Title CO2 activation on TiO2-supported Cu5 and Ni5 nanoclusters : effect of plasma-induced surface charging Type A1 Journal article
  Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 123 Issue 11 Pages 6516-6525  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Surface charging is an often overlooked factor in many plasma-surface interactions and in particular in plasma catalysis. In this study, we investigate the effect of excess electrons induced by a plasma on the adsorption properties of CO2 on titania-supported Cu-5 and Ni-5 clusters using spin-polarized and dispersion-corrected density functional theory calculations. The effect of excess electrons on the adsorption of Ni and Cu pentamers as well as on CO2 adsorption on a pristine anatase TiO2(101) slab is studied. Our results indicate that adding plasma-induced excess electrons to the system leads to further stabilization of the bent CO2 structure. Also, dissociation of CO2 on charged clusters is energetically more favorable than on neutral clusters. We hypothesize that surface charge is a plausible cause for the synergistic effects sometimes observed in plasma catalysis.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000462260700024 Publication Date 2019-02-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 4 Open Access OpenAccess  
  Notes Approved (up) Most recent IF: 4.536  
  Call Number UA @ admin @ c:irua:159422 Serial 5281  
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Author Vermeiren, V.; Bogaerts, A. pdf  url
doi  openurl
  Title Improving the Energy Efficiency of CO2Conversion in Nonequilibrium Plasmas through Pulsing Type A1 Journal article
  Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 123 Issue 29 Pages 17650-17665  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Nonequilibrium plasmas offer a pathway for energy-efficient CO2 conversion through vibrationally induced dissociation. However, the efficiency of this pathway is limited by a rise in gas temperature, which increases vibrational−translational (VT) relaxation and quenches the vibrational levels. Therefore, we investigate here the effect of plasma pulsing on the VT nonequilibrium and on the CO2 conversion by means of a zerodimensional chemical kinetics model, with self-consistent gas temperature calculation. Specifically, we show that higher energy efficiencies can be reached by correctly tuning the plasma pulse and interpulse times. The ideal plasma pulse time corresponds to the time needed to reach the highest vibrational temperature. In addition, the highest energy efficiencies are obtained with long interpulse times, that is, ≥0.1 s, in which the gas temperature can entirely drop to room temperature. Furthermore, additional cooling of the reactor walls can give higher energy efficiencies at shorter interpulse times of 1 ms. Finally, our model shows that plasma pulsing can significantly improve the energy efficiency at low reduced electric fields (50 and 100 Td, typical for microwave and gliding arc plasmas) and intermediate ionization degrees (5 × 10−7 and 10−6).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000477785000003 Publication Date 2019-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 1 Open Access  
  Notes Fonds Wetenschappelijk Onderzoek, G.0383.16N ; This research was supported by the FWO project (grant G.0383.16N). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the UAntwerpen. We also like to thank N. Britun (ChIPS) for the interesting discussions. Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:161621 Serial 5289  
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Author Loenders, B.; Engelmann, Y.; Bogaerts, A. pdf  url
doi  openurl
  Title Plasma-Catalytic Partial Oxidation of Methane on Pt(111): A Microkinetic Study on the Role of Different Plasma Species Type A1 Journal article
  Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C  
  Volume 125 Issue 5 Pages 2966-2983  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT)  
  Abstract We use microkinetic modeling to examine the potential of plasma-catalytic partial oxidation (POX) of CH4 as a promising new approach to produce oxygenates. We study how different plasma species affect POX of CH4 on the Pt(111) surface, and we discuss the associated kinetic and mechanistic changes. We discuss the effect of vibrationally excited CH4 and O2, as well as plasma-generated radicals and stable intermediates. Our results show that vibrational excitation enhances the turnover frequency (TOF) of catalytic CH4 dissociation and has good potential for improving the selectivities toward CH3OH, HCOOH, and C2 hydrocarbons. Nevertheless, when also considering plasma-generated radicals, we find that these species mainly govern the surface chemistry. Additionally, we find that plasma-generated radicals and stable intermediates enhance the TOFs of COx and oxygenates, increase the selectivity toward oxygenates, and make the formation of HCOOH more significant on Pt(111). We also briefly illustrate the potential impact of Eley−Rideal reactions that involve plasma-generated radicals. Finally, we reveal how various radicals affect the catalyst surface chemistry and we link this to the formation of different products. This allows us to make suggestions on how the plasma composition should be altered to improve the formation of desired products.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000619760700017 Publication Date 2021-02-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited Open Access OpenAccess  
  Notes Universiteit Antwerpen; Fonds Wetenschappelijk Onderzoek, S001619N ; H2020 European Research Council, 810182 ; We thank Tom Butterworth for the interesting discussions regarding the calculation of the vibrational populations of methane and for taking the time to share his thoughts and experiences on the matter. This research is supported by the FWO-SBO project PLASMACATDesign (grant number S001619N). We also acknowledge financial support from the TOP-BOF project of the University of Antwerp and from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Program (grant agreement no. 810182SCOPE ERC Synergy project). The calculations were carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (Department EWI), and the University of Antwerp. Approved (up) Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @c:irua:175873 Serial 6672  
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Author Van de Sompel, P.; Khalilov, U.; Neyts, E.C. pdf  url
doi  openurl
  Title Contrasting H-etching to OH-etching in plasma-assisted nucleation of carbon nanotubes Type A1 Journal article
  Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C  
  Volume 125 Issue 14 Pages 7849-7855  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract To gain full control over the growth of carbon nanotubes (CNTs) using plasma-enhanced chemical vapor deposition (PECVD), a thorough understanding of the underlying plasma-catalyst mechanisms is required. Oxygen-containing species are often used as or added to the growth precursor gas, but these species also yield various radicals and ions, which may simultaneously etch the CNT during the growth. At present, the effect of these reactive species on the growth onset has not yet been thoroughly investigated. We here report on the etching mechanism of incipient CNT structures from OH and O radicals as derived from combined (reactive) molecular dynamics (MD) and force-bias Monte Carlo (tfMC) simulations. Our results indicate that the oxygen-containing radicals initiate a dissociation process. In particular, we show how the oxygen species weaken the interaction between the CNT and the nanocluster. As a result of this weakened interaction, the CNT closes off and dissociates from the cluster in the form of a fullerene. Beyond the specific systems studied in this work, these results are generically important in the context of PECVD-based growth of CNTs using oxygen-containing precursors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000641307100032 Publication Date 2021-04-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 4.536 Times cited Open Access OpenAccess  
  Notes Approved (up) Most recent IF: 4.536  
  Call Number UA @ admin @ c:irua:178393 Serial 7729  
Permanent link to this record
 

 
Author Nematollahi, P.; Ma, H.; Schneider, W.F.; Neyts, E.C. pdf  url
doi  openurl
  Title DFT and microkinetic comparison of ru-doped porphyrin-like graphene and nanotubes toward catalytic formic acid decomposition and formation Type A1 Journal article
  Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C  
  Volume 125 Issue 34 Pages 18673-18683  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Immobilization of single metal atoms on a solid host opens numerous possibilities for catalyst designs. If that host is a two-dimensional sheet, sheet curvature becomes a design parameter potentially complementary to host and metal composition. Here, we use a combination of density functional theory calculations and microkinetic modeling to compare the mechanisms and kinetics of formic acid decomposition and formation, chosen for their relevance as a potential hydrogen storage medium, over single Ru atoms anchored to pyridinic nitrogen in a planar graphene flake (RuN4-G) and curved carbon nanotube (RuN4-CNT). Activation barriers are lowered and the predicted turnover frequencies are increased over RuN4-CNT relative to RuN4-CNT. The results highlight the potential of curvature control as a means to achieve high performance and robust catalysts.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000693413400013 Publication Date 2021-08-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited Open Access OpenAccess  
  Notes Approved (up) Most recent IF: 4.536  
  Call Number UA @ admin @ c:irua:181538 Serial 7805  
Permanent link to this record
 

 
Author Neyts, E.C.; Bogaerts, A. openurl 
  Title Numerical study of the size-dependent melting mechanisms of nickel nanoclusters Type A1 Journal article
  Year 2009 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 113 Issue 7 Pages 2771-2776  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Molecular dynamics simulations were used to investigate the size-dependent melting mechanism of nickel nanoclusters of various sizes. The melting process was monitored by the caloric curve, the overall cluster Lindemann index, and the atomic Lindemann index. Size-dependent melting temperatures were determined, and the correct linear dependence on inverse diameter was recovered. We found that the melting mechanism gradually changes from dynamic coexistence melting to surface melting with increasing cluster size. These findings are of importance in better understanding carbon nanotube growth by catalytic chemical vapor deposition as the phase state of the catalyst nanoparticle codetermines the growth mechanism.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2009 IF: 4.224  
  Call Number UA @ lucian @ c:irua:76495 Serial 2410  
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Author Kolev, I.; Bogaerts, A. pdf  doi
openurl 
  Title Numerical study of the sputtering in a dc magnetron Type A1 Journal article
  Year 2009 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Phys Chem C  
  Volume 27 Issue 1 Pages 20-28  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Molecular dynamics simulations were used to investigate the size-dependent melting mechanism of nickel nanoclusters of various sizes. The melting process was monitored by the caloric curve, the overall cluster Lindemann index, and the atomic Lindemann index. Size-dependent melting temperatures were determined, and the correct linear dependence on inverse diameter was recovered. We found that the melting mechanism gradually changes from dynamic coexistence melting to surface melting with increasing cluster size. These findings are of importance in better understanding carbon nanotube growth by catalytic chemical vapor deposition as the phase state of the catalyst nanoparticle codetermines the growth mechanism.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000263299600018 Publication Date 2009-02-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 66 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2009 IF: 4.224  
  Call Number UA @ lucian @ c:irua:71634 Serial 2411  
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Author Wendelen, W.; Dzhurakhalov, A.A.; Peeters, F.M.; Bogaerts, A. pdf  doi
openurl 
  Title Combined molecular dynamics: continuum study of phase transitions in bulk metals under ultrashort pulsed laser irradiation Type A1 Journal article
  Year 2010 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 114 Issue 12 Pages 5652-5660  
  Keywords A1 Journal article; Integrated Molecular Plant Physiology Research (IMPRES); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The phase transition processes induced by ultrashort, 100 fs pulsed laser irradiation of Au, Cu, and Ni are studied by means of a combined atomistic-continuum approach. A moderately low absorbed laser fluence range, from 200 to 600 J/m2 is considered to study phase transitions by means of a local and a nonlocal order parameter. At low laser fluences, the occurrence of layer-by-layer evaporation has been observed, which suggests a direct solid to vapor transition. The calculated amount of molten material remains very limited under the conditions studied, especially for Ni. Therefore, our results show that a kinetic equation that describes a direct solid to vapor transition might be the best approach to model laser-induced phase transitions by continuum models. Furthermore, the results provide more insight into the applicability of analytical superheating theories that were implemented in continuum models and help the understanding of nonequilibrium phase transitions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000275855600044 Publication Date 2010-01-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 2 Open Access  
  Notes ; A.D. gratefully acknowledges Professor M. Hot (ULB, Brussels) for the basic MD-code that was modified further for the laser-induced melting processes. W.W, and A.D. are thankful to Professor L.V. Zhigilei for useful discussions and advices. The calculations were performed on the CALCUA computing facility of the University of Antwerp. This work was supported by the Belgian Science Policy (IAP). ; Approved (up) Most recent IF: 4.536; 2010 IF: 4.524  
  Call Number UA @ lucian @ c:irua:81391 Serial 402  
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Author Khalilov, U.; Neyts, E.C.; Pourtois, G.; van Duin, A.C.T. doi  openurl
  Title Can we control the thickness of ultrathin silica layers by hyperthermal silicon oxidation at room temperature? Type A1 Journal article
  Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 115 Issue 50 Pages 24839-24848  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Using reactive molecular dynamics simulations by means of the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation at room temperature. Oxidation of Si(100){2 × 1} surfaces by both atomic and molecular oxygen was investigated in the energy range 15 eV. The oxidation mechanism, which differs from thermal oxidation, is discussed. In the case of oxidation by molecular O2, silica is quickly formed and the thickness of the formed layers remains limited compared to oxidation by atomic oxygen. The Si/SiO2 interfaces are analyzed in terms of partial charges and angle distributions. The obtained structures of the ultrathin SiO2 films are amorphous, including some intrinsic defects. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry, and more specifically for the fabrication of metal oxide semiconductor devices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000297947700050 Publication Date 2011-11-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 36 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2011 IF: 4.805  
  Call Number UA @ lucian @ c:irua:94303 Serial 273  
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Author Neyts, E.C.; Khalilov, U.; Pourtois, G.; van Duin, A.C.T. doi  openurl
  Title Hyperthermal oxygen interacting with silicon surfaces : adsorption, implantation, and damage creation Type A1 Journal article
  Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 115 Issue 15 Pages 4818-4823  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Using reactive molecular dynamics simulations, we have investigated the effect of single-impact, low-energy (thermal-100 eV) bombardment of a Si(100){2 × 1} surface by atomic and molecular oxygen. Penetration probability distributions, as well as defect formation distributions, are presented as a function of the impact energy for both species. It is found that at low impact energy, defects are created chemically due to the chemisorption process in the top layers of the surface, while at high impact energy, additional defects are created by a knock-on displacement of Si. These results are of particular importance for understanding device performances of silica-based microelectronic and photovoltaic devices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000288401200060 Publication Date 2011-03-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 28 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2011 IF: 4.805  
  Call Number UA @ lucian @ c:irua:89858 Serial 1543  
Permanent link to this record
 

 
Author Delabie, A.; Sioncke, S.; Rip, J.; van Elshocht, S.; Caymax, M.; Pourtois, G.; Pierloot, K. doi  openurl
  Title Mechanisms for the trimethylaluminum reaction in aluminum oxide atomic layer deposition on sulfur passivated germanium Type A1 Journal article
  Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 115 Issue 35 Pages 17523-17532  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Germanium combined with high-κ dielectrics is investigated for the next generations of CMOS devices. Therefore, we study reaction mechanisms for Al2O3 atomic layer deposition on sulfur passivated Ge using calculations based on density functional theory and total reflection X-ray fluorescence (TXRF). TXRF indicates 6 S/nm2 and 4 Al/nm2 after the first TMA/H2O reaction cycle, and growth inhibition from the second reaction cycle on. Calculations are performed on molecular clusters representing −GeSH surface sites. The calculations confirm that the TMA reaction does not affect the S content. On fully SH-terminated Ge, TMA favorably reacts with up to three −GeSH sites, resulting in a near tetrahedral Al coordination. Electron deficient structures with a GeS site shared between two Al atoms are proposed. The impact of the cluster size on the structures and reaction energetics is systematically investigated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000294386000037 Publication Date 2011-08-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 9 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2011 IF: 4.805  
  Call Number UA @ lucian @ c:irua:91714 Serial 1980  
Permanent link to this record
 

 
Author Nourbakhsh, A.; Cantoro, M.; Klekachev, A.V.; Pourtois, G.; Vosch, T.; Hofkens, J.; van der Veen, M.H.; Heyns, M.M.; de Gendt, S.; Sels, B.F. doi  openurl
  Title Single layer vs bilayer graphene : a comparative study of the effects of oxygen plasma treatment on their electronic and optical properties Type A1 Journal article
  Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 115 Issue 33 Pages 16619-16624  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract This contribution presents the effects of a mild O2 plasma treatment on the structural, optical, and electrical properties of single-layer (SLG) and bilayer graphene (BLG). Unexpectedly, we observe only photoluminescence in the SLG parts of a graphene flake composed of regions of various thickness upon O2 plasma treatment, whereas the BLG and few-layer graphene (FLG) parts remain optically unchanged. Confirmed with X-ray photoelectron spectroscopy (XPS) that O2 plasma induces epoxide and hydroxyl-like groups in graphene, density functional theory (DFT) calculations are carried out on representative epoxidized and hydroxylated SLG and BLG models to predict density of states (DOS) and band structures. Sufficiently oxidized SLG shows a bandgap and thus loss of semimetallic behavior, while oxidized BLG maintains its semimetallic behavior even at high oxygen density in agreement with the results of the photoluminescence spectroscopy (PL) experiments. DFT calculations confirm that the Fermi velocity in epoxidized BLG is remarkably comparable with that of pristine SLG, pointing to a similarity of electronic band structure. The similarity is also experimentally demonstrated by the electrical characterization of a plasma-treated BLG-FET. As expected from the electronegative oxygen adatoms in the graphene, epoxidized BLG presents conductive features typical of hole doping. Moreover, the electrical characteristics suggest band structures closely related to that of epoxidized graphene while deviating from that of hydroxylated graphene. Finally, upon O2 plasma treatment of BLG, the four-component 2D peak around 2700 cm1 in the Raman spectrum evolves into a single Lorentzian line, very like the 2D peak of pristine SLG. Summarizing, the data in this contribution recommend that a controlled O2 plasma treatment, which is compatible with CMOS process flow in contrast to wet chemical oxidation methods, provides an efficient and valuable technique to exploit the transport properties of the bottom layer of BLG.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000294077000047 Publication Date 2011-06-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 46 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2011 IF: 4.805  
  Call Number UA @ lucian @ c:irua:91715 Serial 3024  
Permanent link to this record
 

 
Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C. doi  openurl
  Title Hyperthermal oxidation of Si(100)2x1 surfaces : effect of growth temperature Type A1 Journal article
  Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 15 Pages 8649-8656  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Using reactive molecular dynamics simulations based on the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation as a function of temperature in the range 100-1300 K. Oxidation of Si(100){2 x 1} surfaces by both atomic and molecular oxygen was investigated for hyperthermal impact energies in the range of 1 to 5 eV. Two different growth mechanisms are found, corresponding to a low temperature oxidation and a high temperature one. The transition temperature between these mechanisms is estimated to be about 700 K. Also, the initial step of the Si oxidation process is analyzed in detail. Where possible, we validated our results with experimental and ab initio data, and good agreement was obtained. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry and, more specifically, for the fabrication of metal oxide semiconductor devices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000302924900035 Publication Date 2012-03-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 32 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:98259 Serial 1542  
Permanent link to this record
 

 
Author Aerts, R.; Martens, T.; Bogaerts, A. doi  openurl
  Title Influence of vibrational states on CO2 splitting by dielectric barrier discharges Type A1 Journal article
  Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 44 Pages 23257-23273  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this paper, the splitting of CO2 in a pulsed plasma system, such as a dielectric barrier discharge (DBD), is evaluated from a chemical point of view by means of numerical modeling. For this purpose, a chemical reaction set of CO2 in an atmospheric pressure plasma is developed, including the vibrational states of CO2, O2, and CO. The simulated pulses are matched to the conditions of a filament (or microdischarge) and repeated with intervals of 1 μs. The influence of vibrationally excited CO2 as well as other neutral species, ions, and electrons on the CO2 splitting is discussed. Our calculations predict that the electrons have the largest contribution to the CO2 splitting at the conditions under study, by electron impact dissociation. The contribution of vibrationally excited CO2 levels in the splitting of CO2 is found be 6.4%, when only considering one microdischarge pulse and its afterglow, but it can be much higher for consecutive discharge pulses, as is typical for a filamentary DBD, when the interpulse time is short enough and accumulation effects in the vibrationally excited CO2 densities can occur.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000310769300012 Publication Date 2012-10-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 112 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:101764 Serial 1659  
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Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C. doi  openurl
  Title On the c-Si\mid a-SiO2 interface in hyperthermal Si oxidation at room temperature Type A1 Journal article
  Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 41 Pages 21856-21863  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The exact structure and properties of the Si vertical bar SiO2 interface are very important in microelectronics and photovoltaic devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and solar cells. Whereas Si vertical bar SiO2 structures are traditionally produced by thermal oxidation, hyperthermal oxidation shows a number of promising advantages. However, the Si vertical bar SiO2 interface induced in hyperthermal Si oxidation has not been properly investigated yet. Therefore, in this work, the interface morphology and interfacial stresses during hyperthermal oxidation at room temperature are studied using reactive molecular dynamics simulations based on the ReaxFF potential. Interface thickness and roughness, as well as the bond length and bond angle distributions in the interface are discussed and compared with other models developed for the interfaces induced by traditional thermal oxidation. The formation of a compressive stress is observed. This compressive stress, which at the interface amounts about 2 GPa, significantly slows down the inward silica growth. This value is close to the experimental value in the Si vertical bar SiO2 interface obtained in traditional thermal oxidation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000309902100026 Publication Date 2012-09-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 27 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:102167 Serial 2458  
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Author Somers, W.; Bogaerts, A.; van Duin, A.C.T.; Neyts, E.C. pdf  doi
openurl 
  Title Plasma species interacting with nickel surfaces : toward an atomic scale understanding of plasma-catalysis Type A1 Journal article
  Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 39 Pages 20958-20965  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The adsorption probability and reaction behavior of CHx plasma species on various nickel catalyst surfaces is investigated by means of reactive molecular dynamics (MD) simulations using the ReaxFF potential. Such catalysts are used in the reforming of hydrocarbons and in the growth of carbon nanotubes, and further insight in the underlying mechanisms of these processes is needed to increase their applicability. Single and consecutive impacts of CHx radicals (x={1,2,3}) were performed on four different Ni surfaces, at a temperature of 400 K. The adsorption probability is shown to be related to the number of free electrons, i.e. a higher number leads to more adsorptions, and the steric hindrance caused by the hydrogen atoms bonded to the impacting CHx species. Furthermore, some of the CH bonds break after adsorption, which generally leads to diffusion of the hydrogen atom over the surface. Additionally, these adsorbed H-atoms can be used in reactions to form new molecules, such as CH4 and C2Hx, although this is dependent on the precise morphology of the surface. New molecules are also formed by subtraction of H-atoms from adsorbed radicals, leading to occasional formation of H2 and C2Hx molecules.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000309375700040 Publication Date 2012-09-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 37 Open Access  
  Notes Approved (up) Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:101522 Serial 2640  
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