Repurposing metal containing wastes and mass-produced materials as electrocatalysts for water electrolysis

Abstract

The rapid transformation to renewable energy will require an equal uptake of energy storage technologies. Therefore, green hydrogen production via water electrolysis has been touted as a practical solution for large scale energy storage. To further secure an environmentally sustainable future the deployment of electric vehicles and energy generation/storage devices will need to continue. This puts a high demand on scarce resources such as expensive platinum group metals which also results in an emerging waste problem at the end of life of these technologies. However, this provides an opportunity to take advantage of a major metal containing waste stream for urban mining which could relieve the pressure on natural resources and reduce both material and energy consumption. In this review it is outlined that there is an emerging application for this waste, i.e. electrocatalyst fabrication for use in water electrolysis to produce green hydrogen. It is identified that not only are battery materials suitable, but other sources of metal waste such as mass produced materials like stainless steel and refined minerals can be repurposed. Therefore, recycling such waste streams not only relieves the stress on mining ever more scarce elements but presents an opportunity to develop cost effective catalysts for green hydrogen production.