H₂-CO₂ polymer electrolyte fuel cell that generates power while evolving CH₄ at the Pt_0.8Ru_0.2/C cathode

Generating electric power using CO₂ as a reactant is challenging because the electroreduction of CO₂ usually requires a large overpotential. Herein, we report the design and development of a polymer electrolyte fuel cell driven by feeding H₂ and CO₂ to the anode (Pt/C) and cathode (Pt_0.8Ru_0.2/C), respectively, based on their theoretical electrode potentials. Pt-Ru/C is a promising electrocatalysts for CO₂ reduction at a low overpotential; consequently, CH₄ is continuously produced through CO₂ reduction with an enhanced faradaic efficiency (18.2%) and without an overpotential (at 0.20 V vs. RHE) was achieved when dilute CO₂ is fed at a cell temperature of 40 °C. Significantly, the cell generated electric power (0.14 mW cm^-2) while simultaneously yielding CH₄ at 86.3 μmol g^-1 h^-1. These results show that a H₂-CO₂ fuel cell is a promising technology for promoting the carbon capture and utilization (CCU) strategy.