Dual-Gas Activation Nanodomains Enable Solar-Powered Selective Methane Conversion

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Methane conversion to formaldehyde for fuel cells is challenging.
• Developing efficient photocatalysts is crucial for sustainable energy.

Purpose of the Study:

• To develop a novel photocatalyst for methane oxidation to formaldehyde.
• To enable direct utilization of formaldehyde in fuel cells.
• To achieve simultaneous methane valorization and energy conversion.

Main Methods:

• High-throughput screening of 37 earth-abundant transition metals and oxides.
• Fabrication of a dual-gas coadsorption domain architecture using vacancy-rich porous ZnO (pZnO) and reduced nickel oxide (NiO_1-x).
• Solar-driven photocatalytic reactor testing and fuel cell performance evaluation.

Main Results:

• Reduced nickel oxide (NiO_1-x) on pZnO demonstrated optimal performance.
• Achieved 88.5% selectivity for formaldehyde production (28.5 mmol g^-1).
• Solar reactor produced 12.3 mmol g^-1 formaldehyde in 6 hours.
• Directly fueled an alkaline formaldehyde fuel cell, generating 0.2 kWh electricity and formate.

Conclusions:

• The developed photocatalyst enables efficient, solar-driven methane to formaldehyde conversion.
• The process offers a scalable pathway for simultaneous methane valorization and on-site energy generation.
• This technology facilitates direct use of formaldehyde in fuel cells without purification.