Efficient hydrogenation over single-site bimetallic RuSn clusters

Abstract

Hydrogenation of ethene to ethane over single-site Ru_N and (RuSn)_N clusters is investigated using Density Functional Theory calculations. The critical transition state barrier, namely the last hydrogenation step, correlates linearly for Ru_N with the adsorption energies of the reactants. Addition of Sn to the Ru-clusters breaks this relation and allows for lower reaction barriers. In general, Sn is found to have pronounced effects on the geometrical and electronic properties of Ru_N clusters with N ≤ 12. Ru_N clusters preferably adopt cubic conformations with high spin states, whereas (RuSn)_N have low spin states and form compact Ru cores capped with Sn atoms.