Dynamic attraction of leached metal species enables durable glucose electrooxidation in a strong acid

Electrooxidation of organic compounds to produce organic acid in an acidic electrolyte can circumvent product acidification step with high cost in alkaline electrolyte. However, catalysts often suffer from low stability in acid owing to severe leaching. Herein, we report a strategy to dynamically attract leached metal species to stabilize catalyst in a strong acid. In electrooxidation of glucose to formic acid over a lead dioxide (PbO 2 ) catalyst, switching the electrolyte from HClO 4 to H 2 SO 4 reduces Pb 2+ leaching by up to 30 times. As a result, a 275-hour stable performance at 1 A cm ‒2 is achieved in H 2 SO 4 (pH 0.3) using a membrane electrode assembly. Experimental evidence demonstrates that the SO 4 2− ion attracts the leached Pb 2+ —generated from chemical reduction of PbO 2 by glucose—by in-situ forming PbSO 4 precipitate on the electrode, which is then oxidized to the active PbO 2 phase. Benefiting from acidic electrolysis, we achieve raw cellulose conversion to formic acid without intermediate separation through an acid hydrolysis−electrolysis tandem process. This work demonstrates an efficient strategy to stabilize electrocatalysts that suffer from leaching issues in acidic conditions.