Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7721141 | International Journal of Hydrogen Energy | 2013 | 10 Pages |
Abstract
The dehydrogenation of ammonia borane (BH3NH3) catalyzed by Pd supported on an MgO(100) surface was investigated using the DFT/UB3LYP method and an embedded cluster model. We found that BH3NH3 molecules can be initially adsorbed on 2-Pd atom clusters on the MgO surface (Pd2/MgO) in two different configurations, and on 4-Pd atom clusters (Pd4/MgO) in one configuration. One of the two BH3NH3-Pd2/MgO configurations can dehydrogenate in a concerted pathway with a forward free energy barrier of 16.5Â kcal/mol, and the other in a stepwise mechanism with forward barriers of 11.1 and 9.4Â kcal/mol, respectively. However, only a stepwise dehydrogenation pathway was found for the single BH3NH3-Pd4/MgO configuration, with a rate-controlling barrier of 12.6Â kcal/mol. These results suggest that the BH3NH3 dehydrogenation mechanism and reaction barrier height can change with the size of the Pd clusters on the MgO(100) surface.
Keywords
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Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Mingqiong Tong, Zhenfen Yin, Yan Wang, Guangju Chen,