Publication
Title
Propagation of a plasma streamer in catalyst pores
Author
Abstract
Although plasma catalysis is gaining increasing interest for various environmental applications, the underlying mechanisms are still far from understood. For instance, it is not yet clear whether and how plasma streamers can propagate in catalyst pores, and what is the minimum pore size to make this happen. As this is crucial information to ensure good plasma-catalyst interaction, we study here the mechanism of plasma streamer propagation in a catalyst pore, by means of a two-dimensional particle-in-cell/Monte Carlo collision model, for various pore diameters in the nm-range to mu m-range. The so-called Debye length is an important criterion for plasma penetration into catalyst pores, i.e. a plasma streamer can penetrate into pores when their diameter is larger than the Debye length. The Debye length is typically in the order of a few 100 nm up to 1 mu m at the conditions under study, depending on electron density and temperature in the plasma streamer. For pores in the range of similar to 50 nm, plasma can thus only penetrate to some extent and at very short times, i.e. at the beginning of a micro-discharge, before the actual plasma streamer reaches the catalyst surface and a sheath is formed in front of the surface. We can make plasma streamers penetrate into smaller pores (down to ca. 500 nm at the conditions under study) by increasing the applied voltage, which yields a higher plasma density, and thus reduces the Debye length. Our simulations also reveal that the plasma streamers induce surface charging of the catalyst pore sidewalls, causing discharge enhancement inside the pore, depending on pore diameter and depth.
Language
English
Source (journal)
Plasma sources science and technology / Institute of Physics [Londen] - Bristol, 1992, currens
Publication
Bristol : Institute of Physics , 2018
ISSN
0963-0252
Volume/pages
27 :3 (2018) , 10 p.
Article Reference
035009
ISI
000427976800001
Medium
E-only publicatie
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Project info
Multi-scale modeling of plasma catalysis/
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 04.05.2018
Last edited 03.09.2021
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