A High-Capacity, Reversible Liquid Organic Hydrogen Carrier: H2-Release Properties and an Application to a Fuel Cell

Hydrogen storage in the form of a liquid chemical is an important issue that can bridge the gap between sustainable hydrogen production and utilization with a fuel cell, which is one of the essential sectors in the hydrogen economy. Herein, the application of a potential liquid organic hydrogen carrier, consisting of biphenyl and diphenylmethane, is demonstrated as a safe and economical hydrogen storage material. The presented material is capable of a reversible storage and release of molecular hydrogen with 6.9 wt % and 60 g-H2 L–1 of gravimetric and volumetric hydrogen storage capacities, respectively, presenting superior properties as a hydrogen carrier. Equilibrium conversion and the required enthalpies of dehydrogenation are calculated using a density functional theory. Experimentally, dehydrogenation conversion of greater than 99% is achieved, producing molecular hydrogen with greater than 99.9% purity, with negligible side reactions; this is further confirmed by nuclear magnetic resonance spectrosc...