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.