Alloy Engineering in Rational Design of High Current Density Electrode for Efficient Hydrogen Evolution Reaction

Abstract

Alongside rare-earth metals, Ni, Fe, Co, Cu are some of the critical materials that will be in huge demand to foresee the disruptive growth in the clean-energy sector. Understanding the materials criticality, via sustainable approach of recycling, herein for water electrolysis scrap stainless steel wires (SSW) from worn-out tires are employed as a support material for catalyst integration in hydrogen evolution reaction (HER). The cathode scrap SSW with active (alloy) coatings of MoNi4, catalyses HER at η-200 = 77 mV, with low activation energy (Ea = 16.338 kJ mol-1) and high durability of 150 h. Promisingly, MoNi4-SSW electrode under industrial operating conditions of 5 M KOH, 343 K demonstrates abnormal activity by yielding cathodic current density of 1000 mA cm-2 at η = 161 mV respectively. This work may inspire researchers to explore and reutilize high-demand metals from scrap for addressing critical material shortfalls in clean-energy technologies.