Catalytic Activity of Gold Clusters Supported on the h-BN/Au(111) Surface for the Hydrogen Evolution Reaction

It is demonstrated that small gold clusters stabilized on the h-BN/Au(111) support can exhibit high catalytic activity for the hydrogen evolution reaction (HER). Hexagonal boron nitride (h-BN) is usually considered as an inert and insulating support; however, the interaction of a single-layer h-BN with an underlying Au(111) substrate promotes its chemical reactivity, resulting in relatively strong binding of the small gold clusters on the h-BN/Au(111) support with the adsorption energies in the range −0.5 to −1.2 eV. It is shown that the most stable gold clusters on the h-BN/Au(111) support are not necessarily the most reactive; stabilization on the surface gold clusters with the different geometries and orientation with respect to the support can form a large variety of energetically favorable H adsorption sites considerably promoting HER activity. The charge transfer between the supported gold clusters and the h-BN/Au(111) surface promotes the catalytic activity of the Aun@h-BN/Au(111) system for HER. Therefore, h-BN/Au(111) can be considered as a promising support for gold clusters as electrocatalysis.