The Catalytic Role of D-block Elements and Their Compounds for Improving Sorption Kinetics of Hydride Materials: A Review

The goal of finding efficient and safe hydrogen storage material motivated researchers to develop several materials to fulfil the demand of the U.S. Department of Energy (DOE). In the past few years, several metal hydrides, complex hydrides such as borohydrides and alanates, have been researched and found efficient due to their high gravimetric and volumetric density. However, the development of these materials is still limited by their high thermodynamic stability and sluggish kinetics. One of the methods to improve the kinetics is to use catalysts. Among the known catalysts for this purpose, transition metals and their compounds are known as the leading contender. The present article reviews the d-block transition metals including Ni, Co, V, Ti, Fe and Nb as catalysts to boost up the kinetics of several hydride systems. Various binary and ternary metal oxides, halides and their combinations, porous structured hybrid designs and metal-based Mxenes have been discussed as catalysts to enhance the de/rehydrogenation kinetics and cycling performance of hydrogen storage systems.