Magic hybrid structure as multifunctional electrocatalyst surpassing benchmark Pt/C enables practical hydrazine fuel cell integrated with energy-saving H2 production

A hybrid catalyst structure can provide abundant active sites and tailored electronic properties, but the major challenge lies in achieving delicate control over its composition and architecture to improve the catalytic activity toward different electrochemical reactions simultaneously. Herein, we present the rational design of a magic hybrid structure with low Pt loading (5.90 ​wt%), composed of CoPt3 and CoPt nanoparticles supported on N-doped carbon (CoPt3/CoPt⊂PLNC). Importantly, it shows superior multifunctional catalytic activity in alkaline conditions, requiring a low overpotential of 341 and 20 ​mV to achieve 10 ​mA ​cm−2 for the hydrazine oxidation reaction (HzOR)/hydrogen evolution reaction (HER), respectively, and it delivers a half-wave potential of 0.847 ​V for the oxygen reduction reaction (ORR). Theoretical calculations reveal that the metal–carbon hybrid modulates kinetic behavior and induces electron redistribution, achieving the energetic requirements for multiple electrocatalysis. We demonstrate sustainable H2 production utilizing solely the CoPt3/CoPt⊂PLNC catalyst, without external electric power input, suggesting its inspiring practical utility. The featured nanohybrid structure displays highly efficient multifunctional electrocatalysis ability towards hydrazine electrolysis, oxygen reduction, and hydrogen evolution and fulfills the practical applications integrated with energy-saving H2 generation without external electricity input. [Display omitted] •The delicate construction of a metal–carbon nanohybrid enhances electrocatalytic activity exceeding benchmark Pt/C.•Symbiotic CoPt and CoPt3 coupled with carbon enables excellent multifunctional electrocatalytic performance.•An integrated system for green H2 production without external electric power input is demonstrated.