Biofunctionalized conductive polymers enable efficient CO2 electroreduction
Sprache des Titels:
Englisch
Original Kurzfassung:
Selective electrocatalysts are urgently needed for carbon dioxide (CO2) reduction to replace fossil fuels with
renewable fuels, thereby closing the carbon cycle. To date, noble metals have achieved the best performance in
energy yield and faradaic efficiency and have recently reached impressive electrical-to-chemical power conversion
efficiencies.However, the scarcity of preciousmetalsmakes the search for scalable,metal-free, CO2 reduction reaction
(CO2RR) catalysts all themore important. We report an all-organic, that is,metal-free, electrocatalyst that achieves impressive
performance comparable to that of best-in-class Ag electrocatalysts. Wehypothesized that polydopamine?a
conjugated polymer whose structure incorporates hydrogen-bonded motifs found in enzymes?could offer the
combination of efficient electrical conduction, together with rendered active catalytic sites, and potentially thereby
enable CO2RR. Only by developing a vapor-phase polymerization of polydopamine were we able to combine the
needed excellent conductivity with thin film?based processing. We achieve catalytic performance with geometric
current densities of 18 mA cm?2 at 0.21 V overpotential (?0.86 V versus normal hydrogen electrode) for the electrosynthesis of C1 species (carbon monoxide and formate) with continuous 16-hour operation at >80%faradaic
efficiency. Our catalyst exhibits lower overpotentials than state-of-the-art formate-selective metal electrocatalysts (for example, 0.5 V for Ag at 18mAcm?1). The results confirmthe value of exploiting hydrogen-bonded sequences as effective catalytic centers for renewable and cost-efficient industrial CO2RR applications.
Forschungs-