Title: | A first-principles analysis for sulfur tolerance of CeO2 in solid oxide fuel cells |
Authors: | Chen, Hsin-Tsung Choi, YongMan Liu, Meilin Lin, M. C. 應用化學系分子科學碩博班 Institute of Molecular science |
Issue Date: | 26-Jul-2007 |
Abstract: | The mechanism for H2S-CeO2(111) interactions in solid oxide fuel cells (SOFCs) has been investigated by using periodic density functional theory (DFT) calculations. In order to properly characterize the effect of the localization of Ce-4f states on the interactions, DFT + U calculations were applied. Adsorption of H2S, SH, and atomic S was initially examined to locate energetically favorable intermediates. The species adsorb favorably at the Ce-top, O-top, and Ce-O bridging sites, respectively. Potential energy profiles for the H2S-CeO2 (111) interactions along the three product channels producing H-2, H2O, and SO2 were constructed using the nudged elastic band (NEB) method. Calculations show that H2S weakly bounds on CeO2(111) with a small binding energy, followed by dehydrogenation processes, forming surface sulfur species with an exothermicity of 29.9 kcal/mol. Molecular-level calculations demonstrated that the SO2-forming pathway is energetically most favorable. |
URI: | http://dx.doi.org/10.1021/jp0705774 http://hdl.handle.net/11536/10547 |
ISSN: | 1932-7447 |
DOI: | 10.1021/jp0705774 |
Journal: | JOURNAL OF PHYSICAL CHEMISTRY C |
Volume: | 111 |
Issue: | 29 |
Begin Page: | 11117 |
End Page: | 11122 |
Appears in Collections: | Articles |
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