Enhancing Hydrogen Storage: Advancements and Challenges in Liquid Organic Hydrogen Carriers (LOHCs)

Early investigations utilizing heterogeneous catalysts focused on LOHCs such as methylcyclohexane/toluene (6.1 wt % theoretical hydrogen storage capacity), cyclohexane/benzene (7.14 wt %), decalin/naphthalene (7.3 wt %), and perhydro-dibenzyltoluene/dibenzyltoluene (6.2 wt %). Notably, Chiyoda Corp. and Hydrogenious LOHC Technologies have recently commercialized LOHC technologies based on methylcyclohexane/toluene and perhydro-dibenzyltoluene/dibenzyltoluene, respectively. Nonetheless, challenges related to selectivity during (de)hydrogenation reactions, arising from the potential formation of multiple intermediates, still need to be addressed. This provides an opportunity for the exploration of new and more efficient LOHCs.