Optimized base metals electrodeposition on Ni perforated plate type electrodes for high-performance alkaline water electrolysis

Abstract

Hydrogen is considered as one of the key energy carrier for the forthcoming green transition because of its high energy content and harmless combustion products. Water electrolysis, powered by green electricity, is one of the most efficient and promising technologies for H2 production. Cheap and earth abundant metals-based electrocatalysts for Hydrogen Evolution Reaction (HER) are needed to drive a green transition based on hydrogen produced by water electrolysis. Perforated plate type Ni electrodes are prepared by a cost-effective electroforming process, designed to work for water electrolysis in alkaline environment in a flow-through configuration facilitating the release of bubbles produced by HER. The aim of this work is to synthesize a catalyst layer based on NiCuMo alloy produced by an electrodeposition process tailored to maximize electrocatalytic performances, increasing the electrochemical surface active area (more than 50 times) and its activity. HER is studied in aqueous 1 M KOH solution and an overpotential of only 95 mV is measured to reach 100 mA cm−2, assessing a Tafel slope of 61 mV dec−1. 100 h durability test is successfully carried out demonstrating the high chemical and mechanical stability of so-prepared electrodes for next generation alkaline electrolyzers.