Heteroatom-Doped Transition Metal Electrocatalysts for Hydrogen Evolution Reaction

Abstract

Developing efficient and low-cost electrocatalysts for the hydrogen evolution reaction (HER) is important for clean energy systems. Non-noble transition metals are the most promising candidates for replacement of conventional Pt group catalysts for the HER. However, most non-noble metals show poor HER activity due to their intrinsic electronic structures. Herein, we use a multifaceted heteroatom doping method (nitrogen, sulfur, and phosphorus) to directly and continuously fine-tune the electronic structure and HER activity of non-noble metals without changing their chemical composition. As a proof-of-concept, a nitrogen and phosphorus dual-doped Ni catalyst is explored by precisely manipulating doping modes, revealing the best HER performance among all doped Ni catalysts tested. The doping-induced charge redistribution in the Ni metal significantly influences its catalytic performance for the HER in alkaline media, which is confirmed by merging theoretical calculation with synchrotron-based spectroscopy. The principle that can bridge the doping modes and HER activity of the doped catalysts is built with a volcano relationship.