Gram-scale synthesis of N-NiMo/MoO2 heterostructures to boost hydrogen evolution in low-alkalinity anion exchange membrane water electrolysis

Abstract

Anion exchange membrane water electrolysis (AEMWE) presents a practical approach for green H₂ production. However, the cathodic hydrogen evolution reaction (HER) in basic media is still sluggish as the lack of the cost-efficient catalysts for further industrialization. Here, the heterostructured catalysts combining nucleophilic and oxophilic components facilitate water dissociation and enhance HER and synthesized via a facile gel-route, featuring abundant interfaces between N-doped NiMo alloy and MoO₂ particles. The heterostructured catalyst exhibits exceptional HER activity comparable to 60 %PtC catalysts in basic media (pH = 7–14), delivering high current densities of > 1 A cm⁻² with long^-term durability. AEMWE simulation demonstrates a low cell voltage of 1.87 V at 1 A cm⁻², even with dilute 0.1 M KOH electrolyte. DFT calculations support the interfacial excitation that MoO₂ clusters and N-doped NiMo alloy act synergistically to facilitate water dissociation and optimize *H binding, thereby accelerating hydrogen evolution kinetics. This work offers a practical approach for scalable fabrication of high performance, nonprecious-metal-based electrocatalysts for real application of AEMWE.