Highly enhanced bifunctionality by trace Co doping into Ru matrix towards hydrazine oxidation-assisted energy-saving hydrogen production

As an alternative to oxygen evolution reaction (OER), the low-potential hydrazine oxidation reaction (HzOR) can assemble with hydrogen evolution reaction (HER) to fulfill the energy-saving H-2 generation, which demands of developing high-quality bifunctional electrocatalysts for HER and HzOR. Herein, a simple one-pot wet-chemical method was employed to facilely prepared the highly dispersed RuCo alloy particles onto oxygenated carbon black (RuCo/C). With the trace doping of Co into Ru matrix, RuCo/C exhibits the significantly boosted bifunctional activity, superior to the recently reported counterparts, with low potentials of -13.3 and -76.8 mV at 10 mA center dot cm(-2) for HER and HzOR, respectively. Additionally, the novel HER||HzOR electrolysis system just requires a small voltage of 215.4 mV at 100 mA center dot cm(-2), and thus is easily operated under low-energy portable external powers (fuel cell and solar cell) with impressive H-2 production, demonstrating the superiority in energy saving and convenient operation. Moreover, theoretical calculations unclose upon alloying with trace Co, the H2O dissociation energy barrier and hydrogen ad/desorption of HER can be simultaneously optimized on Ru active sites, and the rate-determining energy barrier of HzOR can be also greatly reduced. This study provides one simple but workable approach to prepare high-performance bifunctional HER and HzOR eletrocatalysts, highly promising for the energy-saving H-2 production.