Electrochemical Hydrogen Storage in Amine‐Activated Polydopamine

Abstract Electrochemical hydrogen storage combines the evolution, oxidation, and storage of hydrides from aqueous electrolytes and ionic liquids, but presently requires palladium or rare‐earth metals to achieve significant power capacities. Here hydrogen electrosorption in amine‐activated polydopamine is shown. The organic heterogeneous amine‐hydride yields a gravimetric hydrogen density of 0.44%, corresponding to a 80% hydride‐per‐monomer content, and offers similar reaction kinetics as for palladium and related systems. An initial stability test of 100 electrosorption cycles that demonstrates resilience in acidic media with a tendency for increased capacity over time is included. In situ vibronic amine‐hydride fingerprints corroborate the reversibility and stability of the conversion process and highlight the merits of amine‐activated polydopamines as a heterogeneous organic hydrogen storage system.