Rh for HER electrocatalysis? A critical analysis of recent studies and thoughts on the same

Rhodium and its compounds have recently been reported more often than ever in the literature as hydrogen evolution reaction (HER) electrocatalysts. The recent developments in designing single-atom catalysts and catalytic materials on a sub-nanometer scale have raised a little concern about the abundance of elements in currently used catalysts. This review critically analyzes the history of Rh in HER electrocatalysis, recent progress, prospects, and unaddressed challenges. In addition, highlights on the properties that make Rh and its compounds appropriate for HER electrocatalysis and the recent trends are also detailed citing the key developments. An elaborate and opinionated outlook given at the end details the ways in which further progress with Rh and its compounds as HER electrocatalysts may occur and how it would redefine the use and scope of the same in water electrolyzers. An opinionated review presenting a critical analysis of the use of Rh as an HER electrocatalyst and the recent developments while highlighting the future directions of the same.