Tailored electronic structure of Ru-doped Cu alloy nanospheres on P, N-enriched mesoporous carbon for synergistically enhanced urea electrooxidation

초록

Electrocatalytic urea oxidation reaction (UOR) provides a dual benefit by treating pollution while efficiently producing green hydrogen with low thermodynamic potential, as a promising alternative to the oxygen evolution reaction (OER) despite its sluggish kinetics, which require the use of an efficient electrocatalyst. An innovative catalyst is engineered by using Cu as the base active metal to offer high conductivity, while Ru doping further accelerates the UOR kinetics. Polyaniline (PANI) microtubes doped with P and N act as a conducting support matrix, enhancing electron transport and structural stability. This design yields Ru-doped Cu nanospheres supported on P, N doped mesoporous carbon derived from PANI microtubes (RuCu/P, N-MPC) as an outstanding UOR electrocatalyst. The synthesized catalyst exhibits exceptional UOR performance, with an ultra-low potential of 1.16 V at 10 mA cm−2, thereby highly competing with the benchmark reported catalysts. The catalyst shows high UOR selectivity with a 220 mV difference in potential to OER. Moreover, the catalyst retains 93.46% of its initial current density over 12 h of chronoamperometry and provides a sustained urea electrolysis performance over 100 h. The catalyst achieves 70.3% of urea degradation over 12 h of electrolysis, by the diacetyl monoxime method. Theoretical calculations confirm stronger adsorption affinity for urea over water, which is favorable for further oxidation via sequential dehydrogenation and release of N2 followed by CO2 gas. The d-band center shift facilitates improved electronic conductivity for better UOR kinetics and efficient active site regeneration. From both experimental and theoretical results, the RuCu/P, N-MPC could be employed as a promising, cost effective electrocatalyst for sustainable hydrogen production and environmental remediation. © 2026 Elsevier B.V.

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