Large-Current CO₂ Electromethanation Through Active Hydrogen Regulation Over Carbon Nitride

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electromethanation of CO2 is crucial for energy storage but faces challenges with slow kinetics and hydrogen coupling.
• Developing efficient catalysts is key to overcoming these limitations for commercial viability.

Purpose of the Study:

• To enhance CO2 electromethanation by utilizing carbon nitride (CN) as an active hydrogen adsorption and supply material.
• To improve the interfacial contact between CN and Cu2O catalysts for increased methane production.

Main Methods:

• Facile liquid-assisted exfoliation and electrostatic self-assembly of carbon nitride (CN) with Cu2O catalysts.
• Flow-cell testing to evaluate methane Faradaic efficiency (FECH4) and partial current density.
• In situ ATR-FTIR spectroscopy and Density Functional Theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• Methane production was increased 52-fold compared to pristine Cu2O catalysts.
• Achieved a high FECH4 of 61% and a partial current density of 561 mA cm-2.
• Demonstrated that strengthened interfaces facilitate active hydrogen management and CO2 hydrogenation.

Conclusions:

• The study highlights the critical role of engineered interfaces in dimensional materials for efficient CO2 electromethanation.
• Active hydrogen management via CN materials significantly improves product yield and selectivity.
• This approach offers a valuable reference for other proton-coupled electron transfer (PCET) processes.