Self-Assembled Pd@CeO₂ /γ-Al₂ O₃ Catalysts with Enhanced Activity for Catalytic Methane Combustion

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Palladium-cerium oxide (Pd@CeO2) core@shell nanospheres are crucial for applications like three-way catalysis, CO oxidation, and methane combustion.
• Developing efficient and stable catalysts is essential for environmental applications.

Purpose of the Study:

• To prepare Pd@CeO2 core@shell nanospheres and support them on gamma-alumina (γ-Al2O3) using different methods.
• To evaluate the catalytic performance of the resulting Pd@CeO2/γ-Al2O3 catalysts for methane combustion.

Main Methods:

• Synthesis of Pd@CeO2 core@shell nanospheres via an aqueous phase autoredox reaction.
• Immobilization of Pd@CeO2 nanospheres onto γ-Al2O3 using electrostatic interaction, supramolecular self-assembly, and physical mixing.
• Evaluation of catalytic activity using a model methane combustion reaction and analysis via H2-TPR.

Main Results:

• The Pd@CeO2-S-850 catalyst, prepared via supramolecular self-assembly and calcined at 850 °C, showed superior performance.
• This catalyst achieved a significantly lower light-off temperature (T50 ≈ 364 °C) for methane combustion.
• The catalyst demonstrated excellent stability, with no significant deterioration observed after five catalytic cycles.

Conclusions:

• Supramolecular self-assembly is an effective method for preparing highly active and stable Pd@CeO2/γ-Al2O3 catalysts.
• Strong metal-support interaction and high specific surface area contribute to the enhanced catalytic performance in methane combustion.
• The developed catalyst shows great promise for practical applications in catalytic methane combustion.