Precisely Modulating the Interfacial Oxygen Radicals for Selective Photocatalytic Methane Partial Oxidation to...

Area of Science:

• Materials Science
• Catalysis
• Photochemistry

Background:

• Selective photocatalytic partial oxidation of methane (CH4) to methanol (CH3OH) is a sustainable process.
• Overoxidation by reactive oxygen species (ROS), especially hydroxyl radicals (•OH), limits methanol yield and selectivity.
• Controlling ROS generation is crucial for efficient methane conversion.

Purpose of the Study:

• To develop a photocatalyst for selective methane to methanol conversion under ambient conditions.
• To fine-tune interfacial reactive oxygen species (ROS) dynamics for enhanced yield and selectivity.
• To mitigate methanol overoxidation by controlling ROS generation.

Main Methods:

• Utilized a PdNi alloy cocatalyst supported on TiO2.
• Employed electronic and structural modulation to tune interfacial ROS dynamics.
• Conducted mechanistic studies involving *O protonation and *OH adsorption via d-band center modulation.
• Investigated the effect of Ni incorporation on methanol desorption.

Main Results:

• The PdNi/TiO2 catalyst effectively suppressed the formation of reactive •OH species.
• Achieved a methanol yield of 9557.4 µmol g⁻¹ h⁻¹ with 87.5% selectivity.
• Demonstrated optimized methanol desorption due to Ni incorporation.
• Showcased the catalyst's ability to use molecular O2 as the sole oxidant.

Conclusions:

• The PdNi/TiO2 photocatalyst offers a promising strategy for selective methane to methanol production.
• Interfacial engineering of ROS dynamics is key to controlling photocatalytic oxidation pathways.
• This work advances selective methane conversion technologies with high yield and selectivity.