Capacitance-Type Governance Rather Than Magnitude: MOF-Derived Zn/P Co-Doped Ni₃S₂ for Selective Urea...

A key challenge for high-performance urea oxidation reaction (UOR) electrocatalysis lies in enhancing reaction selectivity and suppressing the competing oxygen evolution reaction (OER). Conventional studies often overemphasize the improvement of capacitance, yet the intrinsic relationship between capacitance type and catalytic selectivity remains largely unexplored. In this work, we break away from the traditional "bigger is better" mindset and focus on the rational regulation of capacitance types to boost UOR selectivity. A Zn/P co-doped Ni₃S₂ electrocatalyst is rationally designed on nickel foam (NF), and the role of capacitance components in governing UOR/OER competition is systematically revealed. We demonstrate that capacitance type, rather than capacitance value, dominates catalytic selectivity. The pseudocapacitance effectively promotes urea adsorption and activation, while excessive double-layer capacitance (C_dl) tends to trigger OER side reactions. Zn doping optimizes intermediate adsorption, and P doping induces oxygen vacancies and tailors capacitance components. Benefiting from the synergistic effect of capacitance regulation and surface electronic modulation, the as-prepared catalyst exhibits outstanding UOR activity and strong anti-OER interference ability. This work provides a reliable strategy for designing highly selective urea oxidation electrocatalysts and offers new insights into the correlation between capacitance types and catalytic selectivity.