CeO₂@SiO₂ Core-Shell Nanostructure-Supported CuO as High-Temperature-Tolerant Catalysts for CO Oxidation

Area of Science:

• Catalysis
• Materials Science
• Environmental Chemistry

Background:

• Supported copper-ceria (CuO-CeO2) catalysts show promise for CO oxidation.
• High temperatures in automotive exhausts cause catalyst sintering and deactivation.

Purpose of the Study:

• To develop a heat-resistant core-shell catalyst for efficient CO oxidation.
• To enhance the stability and durability of CuO-CeO2 catalysts.

Main Methods:

• Fabrication of yCuO-xCeO2@SiO2 core-shell composite catalysts.
• Characterization using temperature-programmed reduction (TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).
• Evaluation of catalytic activity and stability in CO oxidation at high temperatures.

Main Results:

• The 5CuO-50CeO2@SiO2 catalyst achieved full CO conversion around 130°C.
• The core-shell structure significantly improved thermal stability, maintaining 90% CO conversion at 800°C.
• Enhanced reduction ability of CuO species and formation of reactive CO-Cu(I) intermediates were observed.

Conclusions:

• The SiO2 microsphere core-shell structure imparts excellent thermal stability to CuO-CeO2 catalysts.
• These composite catalysts demonstrate high activity and durability for CO oxidation, suitable for real-world applications.
• The enhanced interaction between CuO and CeO2@SiO2 is key to improved catalytic performance.