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Urea oxidation reaction (UOR), an ideal alternative to oxygen evolution reaction (OER), has received increasing attention for realizing energy‐saving H2 production and relieving pollutant degradation. Normally, most studied Ni‐based UOR catalysts pre‐oxidate to NiOOH and then act as active sites. However, the unpredictable transformation of the catalyst's structure and its dissolution and leaching, may complicate the accuracy of mechanism studies and limit its further applications. Herein, a novel self‐supported bimetallic Mo‐Ni‐C3N3S3 coordination polymers (Mo‐NT@NF) with strong metal–ligand interactions and different H2O/urea adsorption energy are prepared, which realize a bidirectional UOR/hydrogen evolution reaction (HER) reaction pathway. A series of Mo‐NT@NF is prepared through a one‐step mild solvothermal method and their multivalent metal states and HER/UOR performance relationship is evaluated. Combining catalytic kinetics, in situ electrochemical spectroscopic characterization, and density‐functional theory (DFT) calculations, a bidirectional catalytic pathway is proposed by N, S‐anchored Mo5+ and reconstruction‐free Ni3+ sites for catalytic active center of HER and UOR, respectively. The effective anchoring of the metal sites and the fast transfer of the intermediate H* by N and S in the ligand C3N3S3H3 further contribute to the fast kinetic catalysis. Ultimately, the coupled HER||UOR system with Mo‐NT@NF as the electrodes can achieve energy‐efficient overall‐urea electrolysis for H2 production.

In the area of water electrolysis, molybdenum sulfide (MoS x ) materials have attracted a lot of interest and investigation due to their platinum-like catalytic activity. Herein, this work describes the synthesis of a novel molybdenum-based coordination metal polymer (CMP) by adding s-triazine-2,4,6-trithiol (C3H3N3S3) ligands under mild conditions, which addresses the issues of poor electrical conductivity and limited exposure of active sites in conventional MoS x materials. Combination of X-ray absorption near-edge spectroscopy, X-ray photoelectron spectroscopy, and in situ Raman spectroscopy identifies the key role of N, S co-coordinated Mo defect site [MoV(O)S x N y ] moieties as active sites in alkaline hydrogen evolution reaction (HER) processes. Benefitting from the good electrical conductivity of the CMP network, the efficient dispersion, and anchoring of the oxygenated molybdenum sites by N and S, the optimized Mo-based CMP exhibits a high-efficiency alkaline HER (η10: 87 mV) with 30,000 CV times cycle stability. This good HER catalyst also shows well durability at 100 mA cm–2 for 80 h in alkaline simulated seawater (1 M KOH + 0.5 M NaCl). This work inspires new ideas to design N, S co-coordinated molybdenum-based CMP electrocatalysts for hydrogen production by commercial alkaline water splitting.

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