Solar‐Driven Redox‐Catalyzed Direct Alcohol Fuel Cells

ABSTRACT Direct alcohol fuel cells (DAFCs) running on liquid alcohols offer higher energy densities and much easier and safer operation than hydrogen. However, DAFCs face significant challenges in using high‐loading Pt‐based catalysts at both the anode and cathode, where the alcohol oxidation reaction and oxygen reduction reaction still suffer slow kinetics, as well as alcohol crossover causing cathode poisoning. Here, we report a breakthrough in alternative solar‐driven redox‐catalyzed direct alcohol fuel cells (SR‐DAFCs), that avoid using Pt catalysts and can operate with a range of alcohols. They mechanistically alter the conventional solid/liquid/gas heterogeneous electrocatalytic reaction pathways, into liquid homogeneous organic redox couples that mediated alcohol photocatalytic oxidation reaction at the anode, and oxygen electrochemical reduction reaction at cathode. The SR‐DAFCs exhibited record high‐power density up to 319.2 mW cm −2 with various alcohols feed, that is 3 times higher than traditional DAFC, demonstrating great potential of using unrefined alcohols as an economical fuel source for wider applications.