Mesoporous Silica-Supported Nanostructured PdO/CeO₂ Catalysts for Low-Temperature Methane Oxidation

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Methane oxidation is crucial for environmental remediation and energy applications.
• Developing efficient low-temperature catalysts remains a significant challenge.
• Nanostructured metal oxides offer promising catalytic properties.

Purpose of the Study:

• To synthesize and characterize nanostructured PdO/CeO₂ catalysts supported on mesoporous SBA-15 silica.
• To evaluate the catalytic activity and stability of these materials for low-temperature methane oxidation.
• To investigate the role of palladium species and oxygen vacancies in catalytic performance.

Main Methods:

• Synthesis via incipient wetness impregnation and surface-assisted reduction.
• Calcination of synthesized materials.
• Catalytic testing for methane oxidation at low temperatures.
• Stability tests in the presence of water.

Main Results:

• The synthesized PdO/CeO₂/SBA-15 catalysts exhibited good activity for low-temperature methane oxidation.
• A catalyst with 5 wt% Pd loading achieved 50% CO₂ conversion at ~290 °C and complete conversion below 360 °C.
• Catalyst stability was assessed in the presence of water.
• Formation of Pd(0) species during the reaction enhanced oxygen vacancies and catalytic activity.

Conclusions:

• Nanostructured PdO/CeO₂ supported on SBA-15 silica are effective catalysts for low-temperature methane oxidation.
• The catalytic performance is linked to the formation of Pd(0) and increased surface oxygen vacancies.
• These catalysts show potential for applications requiring efficient methane conversion under mild conditions.