Highly efficient, selective, and stable photocatalytic methane coupling to ethane enabled by lattice oxygen looping

Area of Science:

• Catalysis
• Materials Science
• Photochemistry

Background:

• Light-driven oxidative coupling of methane (OCM) offers a sustainable route to valuable chemicals.
• Low intrinsic activity and selectivity hinder current photocatalytic OCM approaches.

Purpose of the Study:

• To develop a highly active and selective photocatalyst for OCM.
• To engineer catalytic sites for enhanced methane conversion and C2+ product formation.

Main Methods:

• Integration of bismuth oxide (BiOx) and gold (Au) nanoparticles on a titanium dioxide (TiO2) substrate.
• Rational design of catalytic sites for methane dissociation and C-C coupling.
• Mechanistic studies using a flow reactor under light irradiation.

Main Results:

• The optimal Au/BiOx-TiO2 hybrid catalyst achieved a high conversion rate of 20.8 mmol/g/h.
• Exceptional C2+ product selectivity of 97% was obtained.
• Demonstrated superior catalyst stability through lattice oxygen participation via the Mars-van Krevelen mechanism.

Conclusions:

• Rational catalytic site engineering of Au/BiOx-TiO2 enables efficient photocatalytic OCM.
• The catalyst design promotes methane activation and selective C-C coupling.
• The study highlights a stable and effective approach for sustainable production of multi-carbon chemicals from methane.