NimMon (m + n = 5) Clusters for Hydrogen Electric Reduction: Synergistic Effect of Ni and Mo on the Adsorption and OH Breaking of H2O

High efficient catalysts for hydrogen evolution reaction are crucial for hydrogen production. As potential catalysts for hydrogen evolution reaction, NimMon (m + n = 5) clusters have been studied in the present work on their structures, stabilities, and chemical reactivity toward H2O adsorption, OH bond breaking, and H adsorption with density functional theory based method. Mo is the active site for H2O adsorption and the adsorption strengths vary slightly with NiMo ratio. On the other hand, the split H prefers to form a triangle with Ni and Mo stabilized by the synergistic effect of Ni and Mo, i.e. adsorption on Mo and activation (and stabilization) by Ni. Electro-reduction makes the OH bond breaking barrierless on Ni4Mo, and this rationalizes the high catalytic efficiency of Ni4Mo in hydrogen evolution reaction (in agreement with experiment), and other H2O adsorption related reactions.