Dimeric [Mo2S12]2−Cluster: A Molecular Analogue of MoS2Edges for Superior Hydrogen-Evolution Electrocatalysis

Abstract Proton reduction is one of the most fundamental and important reactions in nature. MoS 2 edges have been identified as the active sites for hydrogen evolution reaction (HER) electrocatalysis. Designing molecular mimics of MoS 2 edge sites is an attractive strategy to understand the underlying catalytic mechanism of different edge sites and improve their activities. Herein we report a dimeric molecular analogue [Mo 2 S 12 ] 2− , as the smallest unit possessing both the terminal and bridging disulfide ligands. Our electrochemical tests show that [Mo 2 S 12 ] 2− is a superior heterogeneous HER catalyst under acidic conditions. Computations suggest that the bridging disulfide ligand of [Mo 2 S 12 ] 2− exhibits a hydrogen adsorption free energy near zero (−0.05 eV). This work helps shed light on the rational design of HER catalysts and biomimetics of hydrogen‐evolving enzymes.