Nitrogen contained rhodium nanosheet catalysts for efficient hydrazine oxidation reaction

The hydrazine oxidation reaction (HzOR) has been considered as a more energy-efficient alternative to the oxygen evolution reaction in water electrolysis. To design efficient electrocatalysts for HzOR, precise engineering of materials is required to increase active sites and build electronic structures. Herein, nitrogen contained face -centered cubic rhodium (N-fcc-Rh) nanosheets are prepared by directly annealing metastable trigonal rhodium oxide precursor in the ammonia atmosphere. Benefiting from the abundant active sites and unique electronic structure, the optimal N-fcc-Rh-300 electrocatalyst achieves an ultra-low working potential of -81 mV (vs. RHE) at 10 mA cm-2 in 1.0 M KOH/0.5 M N2H4. Density functional theory calculations suggest the N element in the N-fcc-Rh electrocatalyst enables to the reduction of the formation energy of the potential-determining step from *NH2NH2 to *NHNH2 for the HzOR process. This work reveals a new strategy to prepare advanced metal elec-trocatalysts for various electrochemical applications.