In situ construction of Ni enriched porous NiAl as long-lived electrode for hydrogen evolution at high current densities

Abstract

Abstract The hydrogen evolution reaction (HER) is a key process in water electrolysis to produce hydrogen, but the development of highly active, stable and cost-effective monolith HER electrocatalysts by simple methods remains a great challenge. Here we report a compelling and powerful strategy to prepare a Ni enriched three-dimensional nanoporous NiAl catalyst which can be directly used as a highly active and long-lived HER electrode in acids. The electrode exhibits low onset overpotential of only −33 mV. Overpotentials of merely −157 mV and −226 mV are needed to reach current densites of −100 and −200 mA cm−2, respectively, superior to recently reported state-of-art Ni-based monolith HER catalysts. The high activity is likely due to in situ obtained nanoporous structure with high surface area and nanosized Ni. Under a medium overpotential of −335 mV, the electrode can sustain −350 mA cm−2 up to 60 h, showing good long-term stability at high current density. The favorable combination of the high activity, stability, facile preparation and low-cost makes the Ni enriched nanoporous NiAl a promising electrocatalyst for high-speed hydrogen production.