Comparative Study of Hypophosphite H2PO−2Adsorption on Ni(111) and Ag(111) Surfaces by DFT

Abstract

AbstractSurface structures and electronic properties of hypophosphiteon Ni(111) and Ag(111) surfaces were investigated by means of density functional theory at B3LYP/6‐31++G(d,p) level. The most stable structure was that in which theadsorbs with its two P–O bonds faced to the substrate surface. The results of the Mulliken population analysis showed that because of the subtle difference of electron configuration, the adsorption energy was larger on the Ni surface than on the Ag surface, and the amounts of both donation and back donation were larger on the Ni(111) surface than on the Ag(111) surface. There were more negative Mulliken charge transfer from H2PO−2to substrate clusters on Ni surface than on Ag surface and more positive Mulliken charges on P atom in Ni4H2PO−2than in Ag4H2PO−2, which means that P atom in Ni4H2PO−2is easily attacked by a nucleophile such as OH−. Thus, H2PO−2is more easily oxidated on Ni(111) surface than on Ag(111) suface. These results indicated that the silver surface is inactive for the oxidation reaction of the hypophosphite anion.