Orderly Nanodendritic Nickel Substitute for Raney Nickel Catalyst Improving Alkali Water Electrolyser.

The development of nonprecious metal catalysts to meet the activity-stability balance at industrial-grade large current densities remains a challenge toward practical alkali-water electrolysis. Here, we develop an orderly nanodendritic nickel (ND-Ni) catalyst that consists of ultrafine nanograins in chain-like conformation, which shows both excellent activity and robust stability for large-current-density hydrogen evolution reaction (HER) in alkaline media, superior to currently-applied Raney nickel (R-Ni) catalyst in commercial alkali-water electrolyser (AWE). The ND-Ni catalyst featured by a three-dimensional (3D) interconnecting microporous structure endows with high specific surface area and excellent conductivity and hydrophilicity, which together afford superior charge/mass transport favorable to HER kinetics at high current densities. An actual AWE with ND-Ni catalyst demonstrates durable water splitting with 1.0 A cm-2 at 1.71 V under industrial conditions and renders a record-low power consumption of 3.95 kW h/Nm3 with an energy efficiency close to 90%. The hydrogen price per gallon of gasoline equivalent (GGE) is calculated to be ∼0.78 US$, which is less than the target of US$2.0/GGE by 2026 from the U.S. Department of Energy. Our results suggest the feasibility of ND-Ni substitute for R-Ni catalyst in commercial AWE. This article is protected by copyright. All rights reserved.