Nickel-based electrodes as catalysts for hydrogen evolution reaction in alkaline media

This paper reports a systematical study on the microstructures and electrochemical properties of nickel-based electrodes as low-cost catalysts for hydrogen evolution reaction (HER) in alkaline media. The electrodeposited Ni-Sn alloy displays a hydrogen overpotential of 137 mV at cathodic polarization current of 200 mA cm^?2, which is lower than that of Raney-Ni and nickel net electrodes. The Tafel results show that the Volmer reaction is the rate determining step of HER for nickel net and Raney-Ni, while the hydrogen evolution reaction is controlled by a peculiar model for deposited Ni-Sn alloy. The energy consumption of alkaline water electrolysis could be reduced from 4.63 to 4.26 kW h/m³H₂ by using Ni-Sn alloy electrodes to replace Raney-Ni in electrolyzers, producing good economic and environmental benefits.