Electrochemical fabrication of Ni‐P‐B ternary catalyst for hydrogen production in proton exchange membrane water electrolyzer

Abstract

Hydrogen production via water electrolysis, which is crucial for addressing climate change, is limited due to the high cost and insufficient activity of the catalyst. Binary-nonmetal transition metal compounds are promising candidates for the hydrogen evolution reaction (HER) owing to the synergetic effect between metal and nonmetal elements. Herein, we report the facile fabrication of Ni phospho-boride catalysts and their compositional effects on HER activity. By controlling the deposition conditions, the elemental compositions were changed to modulate their electronic structures. Particularly, the HER intrinsic activity showed a volcano relationship based on the elemental P content. The optimized catalyst was prepared on a highly roughened substrate, which could be used as a cathode for a proton exchange membrane electrolyzer (PEMWE) single cell. A current density of 1.08 A cm−2 was obtained at a cell voltage of 2.0 V, which is comparable to state-of-the-art PEMWE single cell comprising nonnoble cathodes.