Dehydrogenation mechanisms of ammonia borane catalyzed by Pd atoms adsorbed on an MgO(100) surface

Autor:	Guangju Chen, Mingqiong Tong, Yan Wang, Zhenfen Yin
Rok vydání:	2013
Předmět:	Renewable Energy Sustainability and the Environment Chemistry Ammonia borane Energy Engineering and Power Technology Condensed Matter Physics Photochemistry Catalysis chemistry.chemical_compound Fuel Technology Adsorption Atom Cluster (physics) Physical chemistry Molecule Dehydrogenation
Zdroj:	International Journal of Hydrogen Energy. 38:15285-15294
ISSN:	0360-3199
DOI:	10.1016/j.ijhydene.2013.09.097
Popis:	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 16.5 kcal/mol, and the other in a stepwise mechanism with forward barriers of 11.1 and 9.4 kcal/mol, respectively. However, only a stepwise dehydrogenation pathway was found for the single BH3NH3–Pd4/MgO configuration, with a rate-controlling barrier of 12.6 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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::37cfddcf7fa12625070c3863685f66bd https://doi.org/10.1016/j.ijhydene.2013.09.097 Zobrazit plný text záznamu Full Text from ScienceDirect