Dilute Molybdenum Atoms Embedded in Hierarchical Nanoporous Copper Accelerate the Hydrogen Evolution Reaction

Abstract The development of earth-abundant, non-noble, high-performance hydrogen evolution reaction (HER) electrocatalysts is still a highly challenging but vitally important issue for energy conversion system. Herein, we reported a self-supported Mo modified hierarchical nanoporous Cu as an efficient electrocatalyst for hydrogen evolution. The optimized nanoporous Cu-Mo electrocatalysts with extremely dilute Mo content exhibits a high HER activity with a negligible onset potential, a small Tafel slope, and an excellent durability in alkaline solution. The dealloying process provides nanoporous Cu-Mo electrocatalysts a unique three-dimensional interconnected bicontinuous nanoporous architecture, which can not only offer high-density catalytic active sites for HER, but also accelerate the desorption of hydrogen molecule from catalysts surface. Density functional theory (DFT) calculations reveal that the introducing of Mo into Cu matrix can accelerate water adsorption and dissociation and optimize adsorption-desorption energetics of H intermediates, thus improving the intrinsic HER activity of nanoporous Cu-Mo electrocatalysts.