First Principles Study on the Adsorption and Dehydrogenation of Borohydride on Mn(111)

Abstract

The mechanism of adsorption and dehydrogenation of borohydride (BH₄) on Mn(111) is explored through first principles calculations within Density Functional Theory (DFT). It is found that the preferred sites for adsorption are the bridge site wherein the adsorbate dissociates resulting to BH_2,ads+2H_ads (“ads” means in the adsorbed state on the surface) fragments characterized by the competing d_zz and d_xz,yz interactions of the Mn-d states of the surface with the H-s and B-p states of the adsorbate, and the fcc hollow site wherein the adsorption is molecular. Water molecule is formed when a hydroxyl radical bonds with hydrogen atom on top of an initially adsorbed borohydride. It passes through a metastable state, then an intermediate state and finally the most stable state. [DOI: 10.1380/ejssnt.2011.257]