Records |
Author |
Bal, K.M. |
Title |
Nucleation rates from small scale atomistic simulations and transition state theory |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Chemical Physics |
Abbreviated Journal |
J Chem Phys |
Volume |
155 |
Issue |
14 |
Pages |
144111 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The evaluation of nucleation rates from molecular dynamics trajectories is hampered by the slow nucleation time scale and impact of finite size effects. Here, we show that accurate nucleation rates can be obtained in a very general fashion relying only on the free energy barrier, transition state theory, and a simple dynamical correction for diffusive recrossing. In this setup, the time scale problem is overcome by using enhanced sampling methods, in casu metadynamics, whereas the impact of finite size effects can be naturally circumvented by reconstructing the free energy surface from an appropriate ensemble. Approximations from classical nucleation theory are avoided. We demonstrate the accuracy of the approach by calculating macroscopic rates of droplet nucleation from argon vapor, spanning 16 orders of magnitude and in excellent agreement with literature results, all from simulations of very small (512 atom) systems. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000755502100008 |
Publication Date |
2021-09-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9606 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.965 |
Times cited |
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Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
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Approved |
Most recent IF: 2.965 |
Call Number |
UA @ admin @ c:irua:184937 |
Serial |
8320 |
Permanent link to this record |
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Author |
Bal, K.M. |
Title |
Reweighted Jarzynski sampling : acceleration of rare events and free energy calculation with a bias potential learned from nonequilibrium work |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Chemical Theory And Computation |
Abbreviated Journal |
J Chem Theory Comput |
Volume |
17 |
Issue |
11 |
Pages |
6766-6774 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We introduce a simple enhanced sampling approach for the calculation of free energy differences and barriers along a one-dimensional reaction coordinate. First, a small number of short nonequilibrium simulations are carried out along the reaction coordinate, and the Jarzynski equality is used to learn an approximate free energy surface from the nonequilibrium work distribution. This free energy estimate is represented in a compact form as an artificial neural network and used as an external bias potential to accelerate rare events in a subsequent molecular dynamics simulation. The final free energy estimate is then obtained by reweighting the equilibrium probability distribution of the reaction coordinate sampled under the influence of the external bias. We apply our reweighted Jarzynski sampling recipe to four processes of varying scales and complexities.spanning chemical reaction in the gas phase, pair association in solution, and droplet nucleation in supersaturated vapor. In all cases, we find reweighted Jarzynski sampling to be a very efficient strategy, resulting in rapid convergence of the free energy to high precision. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000718183600008 |
Publication Date |
2021-10-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1549-9618 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.245 |
Times cited |
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Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
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Approved |
Most recent IF: 5.245 |
Call Number |
UA @ admin @ c:irua:184676 |
Serial |
8479 |
Permanent link to this record |
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Author |
Cui, Z.; Zhou, C.; Jafarzadeh, A.; Zhang, X.; Hao, Y.; Li, L.; Bogaerts, A. |
Title |
SF₆ degradation in γ-Al₂O₃ packed DBD system : effects of hydration, reactive gases and plasma-induced surface charges |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Plasma chemistry and plasma processing |
Abbreviated Journal |
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Volume |
43 |
Issue |
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Pages |
635-656 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Packed-bed DBD (PB-DBD) plasmas hold promise for effective degradation of greenhouse gases like SF6. In this work, we conducted a combined experimental and theoretical study to investigate the effect of the packing surface structure and the plasma surface discharge on the SF6 degradation in a gamma-Al2O3 packing DBD system. Experimental results show that both the hydration effect of the surface (upon moisture) and the presence of excessive reactive gases in the plasma can significantly reduce the SF6 degradation, but they hardly change the discharge behavior. DFT results show that the pre-adsorption of species such as H, OH, H2O and O-2 can occupy the active sites (Al-III site) which negatively impacts the SF6 adsorption. H2O molecules pre-adsorbed at neighboring sites can promote the activation of SF6 molecules and lower the reaction barrier for the S-F bond-breaking process. Surface-induced charges and local external electric fields caused by the plasma can both improve the SF6 adsorption and enhance the elongation of the S-F bonds. Our results indicate that both the surface structure of the packing material and the plasma surface discharge are crucial for SF6 degradation performance, and the packing beads should be kept dry during the degradation. This work helps to understand the underlying mechanisms of SF6 degradation in a PB-DBD system. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000966639200001 |
Publication Date |
2023-04-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0272-4324 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.6 |
Times cited |
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Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.6; 2023 IF: 2.355 |
Call Number |
UA @ admin @ c:irua:196033 |
Serial |
8516 |
Permanent link to this record |
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Author |
Tchakoua, T.; Powell, A.D.; Gerrits, N.; Somers, M.F.; Doblhoff-Dier, K.; Busnengo, H.F.; Kroes, G.-J. |
Title |
Simulating highly activated sticking of H₂ on Al(110) : quantum versus quasi-classical dynamics |
Type |
A1 Journal article |
Year |
2023 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
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Volume |
127 |
Issue |
11 |
Pages |
5395-5407 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We evaluate the importance of quantum effects on the sticking of H2 on Al(110) for conditions that are close to those of molecular beam experiments that have been done on this system. Calculations with the quasi-classical trajectory (QCT) method and with quantum dynamics (QD) are performed using a model in which only motion in the six molecular degrees of freedom is allowed. The potential energy surface used has a minimum barrier height close to the value recently obtained with the quantum Monte Carlo method. Monte Carlo averaging over the initial rovibrational states allowed the QD calculations to be done with an order of magnitude smaller computational expense. The sticking probability curve computed with QD is shifted to lower energies relative to the QCT curve by 0.21 to 0.05 kcal/mol, with the highest shift obtained for the lowest incidence energy. Quantum effects are therefore expected to play a small role in calculations that would evaluate the accuracy of electronic structure methods for determining the minimum barrier height to dissociative chemisorption for H2 + Al(110) on the basis of the standard procedure for comparing results of theory with molecular beam experiments. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000971346700001 |
Publication Date |
2023-03-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
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Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.7; 2023 IF: 4.536 |
Call Number |
UA @ admin @ c:irua:196071 |
Serial |
8525 |
Permanent link to this record |
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Author |
Kelly, S.; Mercer, E.; De Meyer, R.; Ciocarlan, R.-G.; Bals, S.; Bogaerts, A. |
Title |
Microwave plasma-based dry reforming of methane: Reaction performance and carbon formation |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Journal of CO2 utilization |
Abbreviated Journal |
Journal of CO2 Utilization |
Volume |
75 |
Issue |
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Pages |
102564 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
e investigate atmospheric pressure microwave (MW) plasma (2.45 GHz) conversion in CO2 and CH4 mixtures (i.e., dry reforming of methane, DRM) focusing on reaction performance and carbon formation. Promising energy costs of ~2.8–3.0 eV/molecule or ~11.1–11.9 kJ/L are amongst the best performance to date considering the current state-of-the-art for plasma-based DRM for all types of plasma. The conversion is in the range of ~46–49% and ~55–67% for CO2 and CH4, respectively, producing primarily syngas (i.e., H2 and CO) with H2/CO ratios of ~0.6–1 at CH4 fractions ranging from 30% to 45%. Water is the largest byproduct with levels ranging ~7–14% in the exhaust. Carbon particles visibly impact the plasma at higher CH4 fractions (> 30%), where they become heated and incandescent. Particle luminosity increases with increasing CH4 fractions, with the plasma becoming unstable near a 1:1 mixture (i.e., > 45% CH4). Electron microscopy of the carbon material reveals an agglomerated morphology of pure carbon nanoparticles. The mean particle size is determined as ~20 nm, free of any metal contamination, consistent with the electrode-less MW design. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
001065310000001 |
Publication Date |
2023-08-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2212-9820 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.7 |
Times cited |
6 |
Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
We acknowledge financial support by a European Space Agency (ESA) Open Science Innovation Platform study (contract no. 4000137001/21/NL/GLC/ov), the European Marie Skłodowska-Curie Individual Fellowship ‘‘PENFIX’’ within Horizon 2020 (grant no. 838181), the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Program (grant no. 810182; SCOPE ERC Synergy project), the Excellence of Science FWOFNRS PLASyntH2 project (FWO grant no. G0I1822N and EOS no. 4000751) and the Methusalem project of the University of Antwerp |
Approved |
Most recent IF: 7.7; 2023 IF: 4.292 |
Call Number |
PLASMANT @ plasmant @c:irua:198155 |
Serial |
8807 |
Permanent link to this record |
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Author |
Khalilov, U.; Yusupov, M.; Eshonqulov, Gb.; Neyts, Ec.; Berdiyorov, Gr. |
Title |
Atomic level mechanisms of graphene healing by methane-based plasma radicals |
Type |
A1 Journal article |
Year |
2023 |
Publication |
FlatChem |
Abbreviated Journal |
FlatChem |
Volume |
39 |
Issue |
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Pages |
100506 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000990342500001 |
Publication Date |
2023-04-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2452-2627 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
6.2 |
Times cited |
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Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
U.K., M.Y. and G.B.E. acknowledge the support of the Agency for Innovative Development of the Republic of Uzbekistan (Grant numbers F-FA-2021-512 and FZ-2020092435). The computational resources and services used in this work were partially provided by the HPC core facility CalcUA of the Universiteit Antwerpen and VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government. |
Approved |
Most recent IF: 6.2; 2023 IF: NA |
Call Number |
PLASMANT @ plasmant @c:irua:197442 |
Serial |
8813 |
Permanent link to this record |
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Author |
Ndayirinde, C.; Gorbanev, Y.; Ciocarlan, R.-G.; De Meyer, R.; Smets, A.; Vlasov, E.; Bals, S.; Cool, P.; Bogaerts, A. |
Title |
Plasma-catalytic ammonia synthesis : packed catalysts act as plasma modifiers |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Catalysis today |
Abbreviated Journal |
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Volume |
419 |
Issue |
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Pages |
114156-12 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We studied the plasma-catalytic production of NH3 from H2 and N2 in a dielectric barrier discharge plasma reactor using five different Co-based catalysts supported on Al2O3, namely Co/Al2O3, CoCe/Al2O3, CoLa/Al2O3, CoCeLa/Al2O3 and CoCeMg/Al2O3. The catalysts were characterized via several techniques, including SEM-EDX, and their performance was compared. The best performing catalyst was found to be CoLa/Al2O3, but the dif-ferences in NH3 concentration, energy consumption and production rate between the different catalysts were limited under the same conditions (i.e. feed gas, flow rate and ratio, and applied power). At the same time, the plasma properties, such as the plasma power and current profile, varied significantly depending on the catalyst. Taken together, these findings suggest that in the production of NH3 by plasma catalysis, our catalysts act as plasma modifiers, i.e., they change the discharge properties and hence the gas phase plasma chemistry. Importantly, this effect dominates over the direct catalytic effect (as e.g. in thermal catalysis) defined by the chemistry on the catalyst surface. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000987221300001 |
Publication Date |
2023-04-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0920-5861 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.3 |
Times cited |
3 |
Open Access ![sorted by Open Access field, ascending order (up)](img/sort_asc.gif) |
OpenAccess |
Notes |
This research was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 810182 – SCOPE ERC Synergy project) and the Methusalem project of the University of Antwerp. We also gratefully acknowledge the NH3-TPD analysis performed by Sander Bossier. |
Approved |
Most recent IF: 5.3; 2023 IF: 4.636 |
Call Number |
UA @ admin @ c:irua:197268 |
Serial |
8917 |
Permanent link to this record |