Co-generation of electricity and formate in glycerol fuel cells with a bifunctional PdPtAg alloy nanowire electrocatalyst

With the development of the biodiesel industry, the annual production of the byproduct glycerol has increased to a level of nearly millions of tons. Efficient and clean utilization of glycerol is thus urgent and profitable. Direct glycerol fuel cells (DGFCs) capable of selective oxidation of glycerol and co-generation of electricity and high-value added chemicals seem to be the most compelling technique. Unfortunately, selective and durable electrocatalysts for fabricating DGFCs are still not available so far. Herein, ternary Pt-Pd-Ag alloy nanowires (NWs) are designed and synthesized under the direction of the d-band theory. The resulting Pd-Pt-Ag NWs exhibit significant activity towards the glycerol electro-oxidation reaction (GOR) and oxygen reduction reaction (ORR) in an alkaline medium, which outperforms the bimetallic Pt-Ag alloy NWs and the commercial Pt/C benchmark. Moreover, a homemade DGFC based on bifunctional Pd-Pt-Ag NW anode and cathode can achieve a peak power density of 13.7 mW cm(-2) under ambient conditions (similar to 50% enhancement compared to the DGFC based on the Pt/C benchmark) and deliver a record voltage of 1.13 V ever reported in alcohol-feeding fuel cells. Besides the electricity profits, the DGFC concurrently generates value-added formate as a selective product of glycerol oxidization.