Single atom Pd anchored on In-MIL-68-bpy for selective photothermal catalytic methane oxidation to formaldehyde

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Methane oxidation is crucial for chemical synthesis.
• Selective oxidation of methane to formaldehyde remains challenging.
• Photothermal catalysis offers a sustainable approach for chemical reactions.

Purpose of the Study:

• To develop a highly selective catalyst for methane oxidation to formaldehyde.
• To investigate the mechanism of single-atom palladium catalysis in photothermal oxidation.
• To utilize water as a solvent for a greener catalytic process.

Main Methods:

• Synthesis of single-atom palladium anchored on In-MIL-68-bpy.
• Photothermal catalytic oxidation of methane in aqueous solution.
• Characterization of the catalyst and reaction intermediates.
• Analysis of reaction products, including formaldehyde and carbon dioxide.

Main Results:

• Single-atom Pd anchored on In-MIL-68-bpy demonstrated high selectivity for methane to formaldehyde conversion.
• The catalyst achieved a formaldehyde formation rate of 1.9 mmol g_cat^-1 h^-1 at 120 °C.
• The Pd-N site was identified as crucial for oxygen activation and controlling reactive oxygen species.
• Deep oxidation to carbon dioxide was significantly suppressed.

Conclusions:

• Single-atom Pd/In-MIL-68-bpy is an effective catalyst for selective methane to formaldehyde production via photothermal oxidation.
• The catalyst design and active site play a key role in achieving high selectivity and activity.
• This work presents a promising pathway for sustainable methane valorization in aqueous media.