An Electrochemical Ethylamine/Acetonitrile Redox Method for Ambient Hydrogen Storage

Hydrogen storage presents a major difficulty in the development of hydrogen economy. Herein, we report a new electrochemical ethylamine/acetonitrile redox method for hydrogen storage with an 8.9 wt.% theoretical storage capacity under ambient conditions. This method exhibits low onset overpotentials of 0.19 V in CH3CH2NH2 dehydrogenation to CH3CN and 0.09 V in CH3CN hydrogenation to CH3CH2NH2 using commercial Pt black catalyst. By assembling a full cell that couples CH3CH2NH2/CH3CN redox reactions with hydrogen evolution and oxidation reactions, we demonstrate a complete hydrogen storage cycle at fast rates, with only 52.5 kJ/mol energy consumption for H2 uptake and release at a rate of 1 L/m2·h. This method provides a viable hydrogen storage strategy that meets the 2025 Department of Energy onboard hydrogen storage target.