Pd Nanoparticles Versus Single Atoms on CuTi-LDH: Reversing Photoinduced Charge Transfer to Switch Radical Generation...

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Photocatalytic conversion of methane to liquid products is a key strategy for methane valorization and chemical production.
• Achieving high yield and selectivity in methane conversion is challenging due to complex reaction pathways.

Purpose of the Study:

• To develop a highly efficient catalyst for photocatalytic methane conversion to liquid oxygenates.
• To investigate the mechanism behind enhanced catalytic performance in methane conversion.

Main Methods:

• Synthesis and characterization of palladium nanoparticle-supported CuTi layered double hydroxide (Pd_NPs-CuTi-LDH) catalyst.
• Photocatalytic methane conversion experiments.
• In situ X-ray absorption fine structure (XAFS) analyses and theoretical calculations.

Main Results:

• Pd_NPs-CuTi-LDH catalyst achieved a high C1 liquid-oxygenates yield (7220.7 µmol g⁻¹ h⁻¹) and 99.7% selectivity.
• Catalyst performance is determined by ·OH and ·OOH radical concentrations.
• Pd size modulation induced spatial separation of photogenerated electrons and holes, enhancing charge transfer.

Conclusions:

• Pd nanoparticle size is crucial for optimizing photocatalytic methane conversion.
• The developed Pd_NPs-CuTi-LDH catalyst offers a superior and selective route for methane utilization.
• Understanding radical formation pathways is key to designing efficient catalysts for methane conversion.