Abstract
AbstractElectrochemical 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.
Highlights
Electrochemical hydrogen storage combines the evolution, oxidation, and reactions such as metal oxidation and latstorage of hydrides from aqueous electrolytes and ionic liquids, but presently requires palladium or rare-earth metals to achieve significant power capacities
Amines in conducting polydopamine were shown to steer electrocatalytic selectivity in different directions (Figure 1): Secondary amines, such as in the condensed indoline and indole-fragments, implement hydrogen evolution reaction (HER).[46,47,48]. Primary amines, such as present in the dopamine (-DA-)n building block, possessed too high binding energies so that they suppress the hydrogen evolution but enable hydrogen electrosorption (HES). We found it attractive to harness electrocatalytic amines in dopamine for a heterogeneous amine-hydride with the aim to substitute classic PdHx and related metal composite systems
We modified the oxidative chemical vapor deposition (oCVD) in the sense to reduce the temperature in the reaction zone to maximum 150 °C to balance the oxidation power and to favor the direct oxidative polymerization of dopamine, whilst suppressing its unwanted oxidation to i) dopaminequinone or ii) leucodopaminechrome and 5,6-dihydroxyindole
Summary
Electrochemical hydrogen storage combines the evolution, oxidation, and reactions such as metal oxidation and latstorage of hydrides from aqueous electrolytes and ionic liquids, but presently requires palladium or rare-earth metals to achieve significant power capacities. This amine-activated polydopamine (aaPDA) showed effective HES similar to palladium with a maximum of the hydrogen capacity close to −0.2 V versus RHE.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
