Phosphorus incorporation in cobalt molybdate: Controlling Mo leaching for surface reconstruction to improve hydrogen evolution

The development of efficient and durable electrocatalysts for the hydrogen evolution reaction (HER) in alkaline media remains a major challenge due to sluggish reaction kinetics and structural instability of non-noble metal catalysts. Herein, we report a phosphorus-incorporated cobalt molybdate (CoMoO-P) catalyst for regulating the dynamic reconstruction process of Mo-based materials during alkaline HER. Notably, the incorporated P not only enhances electron density at Mo/Co active sites to optimize intermediate adsorption but also regulates the Mo leaching-redeposition dynamics, distinguishing from prior P-doping strategies with a focus solely on electronic modulation. Importantly, the controlled leaching of Mo facilitates the Co(OH) 2 formation that enhances HER kinetics. As a result, CoMoO-P delivers a low overpotential of 42 mV at 10 mA cm −2 and exhibits outstanding durability at various current densities of 100, 500, and 1 A cm −2 for total of 500 h. This study offers a promising strategy for regulating catalyst reconstruction and advancing the design of high-performance non-noble metal HER electrocatalysts.