A Dual-Carbide Heterostructure Interface-Driven Broad pH Range Hydrogen Fuel Production

The development of efficient and cost-effective electrocatalysts for sustainable hydrogen production remains crucial for transitioning to a carbon-neutral energy economy. We present a dual-carbide heterostructure interface that demonstrates an exceptional hydrogen evolution reaction (HER) performance across a wide pH range. The catalyst achieves low overpotentials comparable to platinum benchmarks and maintains stability during extended operation in acidic, neutral, and alkaline electrolytes. The pH-universal performance arises from the optimized hydrogen adsorption and desorption energetics at the heterointerface, which induces synergistic effects that improve the overall reaction kinetics of the HER. Density functional theory calculations reveal that the incorporation of dual carbide heterostructure alters the electronic landscape with a favorable ΔG_H* of ∼0.34 eV, which is closer to the thermoneutral value compared to the individual carbides. When tested in a saline-water electrolyzer, the catalyst delivers long-term consistent performance for 200 h without observable degradation. This work advances nonprecious metal HER catalysis by demonstrating how interface engineering can achieve performance comparable to noble metals, while offering superior stability and cost-effectiveness.