Interfacial Ni–Te Bond-Length Engineering Enables Selective Urea Oxidation for Sustainable Hydrogen Production and Nitrogen Recovery

Nickel-based catalysts are top candidates for urea oxidation-assisted H2 production, enabling green energy and wastewater remediation. However, they suffer from NOx– formation and degradation due to uncontrolled urea peroxidation during the urea oxidation reaction (UOR). Here, we propose a bond-length engineering strategy for nickel telluride (NiTe) catalysts to modulate the interfacial electronic environment and suppress undesired urea peroxidation. With precise elongation of the Ni–Te bond from 2.49 Å to 2.71 Å, the NiTe catalyst shows asymmetric charge distribution and its d-band center shifts further away the Fermi level, thereby promoting OH– adsorption at the electrode–electrolyte interface. This facilitates Ni3+–O layer formation, stabilizing the *H2NCNO intermediate and enabling N≡N coupling while suppressing C–N bond cleavage. The catalyst reached 100 mA cm–2 at 1.33 V vs RHE with high N2 selectivity maintained even at 1.75 V vs RHE. A membrane electrode assembly using the optimized NiTe catalyst delivers 1000 mA cm–2 at 1.55 V with >1250 h of stable operation and high N2 Faradaic efficiency. Integrated into a photovoltaic-electrocatalysis system, it achieves 11.2 ± 0.6% STH efficiency and 9.39 mmol cm–2 h–1 H2 output with >80% N2 selectivity. This work offers a targeted design strategy for selective and durable UOR catalysts in sustainable hydrogen energy conversion systems.