From Methane to Methanol: Pd-iC-CeO₂ Catalysts Engineered for High Selectivity via Mechanochemical Synthesis.

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Selective conversion of methane to methanol is a significant challenge in chemical synthesis.
• Existing methods often suffer from low selectivity, producing undesirable byproducts or combustion products.

Purpose of the Study:

• To develop a highly selective catalyst for direct methane to methanol conversion.
• To investigate the role of catalyst structure and reaction conditions on selectivity.

Main Methods:

• Mechanochemical synthesis of monometallic Pd-CeO2 catalysts modified by interfacial carbon (iC).
• Liquid-phase methane conversion using hydrogen peroxide as the oxidizing agent at 75°C.
• Density functional theory (DFT) simulations to elucidate the reaction mechanism.

Main Results:

• The Pd-iC-CeO2 catalyst achieved 100% selectivity towards methanol.
• A yield of 117 μmol/gcat was obtained at 75°C.
• DFT simulations revealed a critical role of solvent interactions and an Eley-Rideal-like mechanism.

Conclusions:

• A novel mechanochemically synthesized Pd-iC-CeO2 catalyst enables highly selective direct conversion of methane to methanol.
• The unique interfacial carbon and solvent interactions are key to achieving exclusive methanol selectivity.
• This work presents a promising pathway for efficient methanol synthesis from methane.