Role of OH bonding in catalytic activity of Nb2O5 during the course of dehydrogenation of MgH2

Abstract

AbstractThe hydrogen desorption reaction of MgH2, MgH2 → Mg + H2, is accelerated by the addition of metal oxide catalysts (e.g., Nb2O5). From our theoretical calculation of electronic structure, it was predicted that the catalytic activities of metal oxides are related closely to the OH interaction operating at the interface between oxide catalyst and MgH2. In this study, the OH vibration on the Nb2O5‐catalyzed MgH2 was investigated experimentally using FTIR spectroscopy. The broad absorption band due to the OH stretching mode was observed in the region of 2,800–3,600 cm−1 in the FTIR spectra of the specimens when hydrogen desorption reaction was in progress. The absorbance of the band decreased monotonously with decreasing hydrogen content in the specimen during the course of dehydrogenation of MgH2. This experimental result was in agreement with our prediction for the existence of OH interaction in the hydrogen desorption process. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011