Hydrogen storage, a key technology for the sustainable green economy: current trends and future challenges

Abstract

Green hydrogen has the potential to replace fossil fuels in the energy sector and to meet environmental goals with zero-carbon emission. One of key enabling technologies for this energy transition is hydrogen storage. Industry and society demand very diverse storage options from small to large-scale, including both mobile and stationary applications. This review provides a broad overview of the appealing systems and recent developments in this field by discussing the major proposed strategies. Special emphasis is placed on reviewing the efforts made in improving the material’s hydrogen storage capacity and hydrogenation/dehydrogenation properties. We discuss molecular hydrogen storage and hydrogen storage in compounds, as well as their intended ap-plications in on-board mobile or stationary depot. On-board applications are already utilizing compressed gas, liquid hydrogen, and interstitial metal hydrides and research efforts are focusing on improving storage properties. Large efforts are being devoted to developing hydrogen delivery systems using main group metal hydrides, transition metal complex hydrides, tetrahydroborates, tetrahydroaluminates, and their composites, as well as molecular liquids. Technologies are maturing for large-scale storage in underground facilities and for utilizing liquid hydrogen carriers.