Review and Perspective of Nickel and Its Derived Catalysts for Different Electrochemical Synthesis Reactions in Alkaline Media for Hydrogen Production

Abstract

Hydrogen (H 2 ) is a promising alternative energy source, but its current production method through steam reforming is energy intensive and polluting. Water electrolysis, specifically the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), offers a cleaner option. Although HER is the favorable process, OER needs a larger overpotential, thereby hindering practical implementation. The use of expensive noble metal-based catalysts limits the application. The levelized cost of hydrogen can be lowered by replacing the anodic reaction with several innovative strategies. Alternative oxidation reactions have emerged as some of the most noteworthy new strategies. A critical analysis of electrochemical synthesis reactions (ESR) combining anodic chemical synthesis and cathodic hydrogen evolution is presented here for replacing the traditional OER with organic molecule oxidation. This review aims to explore nickel and nickel-based catalysts for different ESR reactions, such as alcohol, aldehydes, amines, and biomass-derived compounds, for energyefficient and cost-effective electrocatalytic hydrogen production. In this critical review, we present a clear picture of the challenges and bottlenecks associated with electrochemical synthesis reactions as a method of industrial hydrogen production needs. Finally, a perspective and challenges for future development of the hybrid water electrolysis techniques are demonstrated.

Selective lactic acid synthesis via ethylene glycol electrooxidation in borate buffer

“…A limited number of studies report highly active EGOR catalysts based on earth-abundant materials and only a few exhibit high selectivity towards value-added products. 9 As for non-noble metal-containing electrocatalysts, Ni-based ones have been the most extensively investigated, 10,11 most in highly basic conditions reporting formic acid as the major product. 10 This suggests that EGOR on Ni-based catalysts involves significant C–C cleavage.…”