Enhancing Nimo Electrocatalyst Durability Through Cr Doping and Nitrogen Carbon Coating for Fluctuant Electricity-Driven Water Electrolysis

Electrolyzing water with solar and wind power produces environmentally friendly green hydrogen. NiMo, with its high activity, is considered a promising alternative to Pt for hydrogen evolution reaction (HER). However, with intermittent renewables, NiMo catalyst degrades significantly due to oxidation or corrosion. To enhance NiMo's durability, we have implemented an innovative double insurance strategy to prepare hierarchical NiMoCr micropillars covered by an ultrathin carbon layer. The incorporation of Cr internally optimizes the electron density, preserving Ni valence states and acting as a protectant against oxidation. The immersion and pyrolysis steps introduce ultra-thin carbon layer on NiMoCr surface. The NiMoCr@NC exhibits low overpotential, high current densities and remarkable stability under ON/OFF electrolysis, even in acidic environments. Furthermore, DFT calculations confirm Cr doping prevents Ni oxidation and validates the beneficial influence of the active components. These results highlight its potential as an efficient and durable catalyst for renewable energy-driven water electrolysis.