Current research progress and perspectives on liquid hydrogen rich molecules in sustainable hydrogen storage

Hydrogen gas is regarded as an ideal clean energy carrier to substitute fossil-based fuels. However, develop safe, efficient, and economical hydrogen storage approaches is still a big challenge in engineering for real applications. Recently, liquid hydrogen rich molecules have attracted great attention, because of their high hydrogen content, low potential risk, and reasonable cost. This review is to summarize the latest developments of hydrogen generation from liquid hydrogen rich molecules (i.e. formic acid, alcohols, ammonia, hydrous hydrazine, primary amines, and liquid organic hydrogen carriers (LOHCs)) and their regeneration, demonstrating the state-of-the-art liquid-phase hydrogen storage technology. Notably, the development of highly active catalysts and the related catalytic systems to accelerate the evolution of the catalytic hydrogenation and dehydrogenation of hydrogen rich chemicals, making the circular hydrogen economy feasible and affordable.