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

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Electrocatalytic reduction of carbon dioxide (CO₂) to generate electric power is hindered by high overpotentials.
• Developing efficient catalysts and fuel cell designs is crucial for CO₂ utilization.

Purpose of the Study:

• To design and develop a polymer electrolyte fuel cell (PEFC) that utilizes H₂ and CO₂ to produce electricity and methane (CH₄).
• To investigate the performance of a Pt-Ru/C electrocatalyst for CO₂ reduction at low overpotentials.

Main Methods:

• A PEFC was constructed with a Pt/C anode and a Pt_0.8Ru_0.2/C cathode.
• The cell was operated with H₂ and CO₂ feeds at a cell temperature of 40 °C.
• Electrode potentials and methane production rates were measured.

Main Results:

• The Pt-Ru/C cathode facilitated CO₂ reduction to CH₄ with a faradaic efficiency of 18.2% at a low overpotential (0.20 V vs. RHE).
• The H₂-CO₂ fuel cell generated electric power of 0.14 mW cm^-2.
• Methane was produced at a rate of 86.3 μmol g^-1 h^-1.

Conclusions:

• A H₂-CO₂ fuel cell utilizing a Pt-Ru/C catalyst can simultaneously generate electric power and produce CH₄.
• This technology demonstrates a viable approach for carbon capture and utilization (CCU).
• The low overpotential achieved highlights the potential for efficient CO₂ electroreduction.