Ruthenium Nanoclusters and Single Atoms on α‐MoC/N‐Doped Carbon Achieves Low‐input/Input‐free Hydrogen Evolution via Decoupled/Coupled Hydrazine Oxidation

Abstract

The hydrazine oxidation‐assisted H2 evolution method promises low‐input and input‐free hydrogen production. However, developing high‐performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α‐MoC/N‐C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α‐MoC nanoparticles‐decorated N‐doped carbon (α‐MoC/N‐C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring ‐80 mV and ‐9 mV respectively to reach 10 mA cm‐2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H adsorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α‐MoC/N‐C/RuNSA excels as both anode and cathode materials, achieving 10 mA cm‐2 at just 64 mV. The zinc hydrazine (Zn‐Hz) battery assembled with α‐MoC/N‐C/RuNSA cathode and Zn foil anode can exhibit 96% energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn‐Hz with OHzS system enables self‐powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell‐integrated‐electrolyzer system.