Construction of a Pd(PdO)/Co₃O₄@SiO₂ core-shell structure for efficient low-temperature methane combustion

Area of Science:

• Environmental Science
• Catalysis
• Materials Science

Background:

• Methane (CH4) combustion is crucial for environmental protection.
• Low-temperature methane activation is challenging due to the strong C-H bond.
• Developing efficient catalysts for low-temperature methane combustion is essential.

Purpose of the Study:

• To design and synthesize a highly active core-shell catalyst for low-temperature methane combustion.
• To investigate the structure-activity relationship of the novel catalyst.
• To understand the mechanism behind enhanced catalytic performance.

Main Methods:

• Synthesis of Pd(PdO)/Co3O4@SiO2, Pd(PdO)/SiO2, and Co3O4@SiO2 catalysts.
• Characterization using various techniques (e.g., XRD, TEM, XPS).
• Evaluation of catalytic activity in methane combustion, determining T50% and T90% values.

Main Results:

• The Pd(PdO)/Co3O4@SiO2 core-shell catalyst exhibited significantly higher activity than non-core-shell counterparts.
• T50% and T90% for the core-shell catalyst were 357 °C and 445 °C, respectively.
• Enhanced metal interaction and weakened Co-O bonds were observed in the core-shell structure.

Conclusions:

• The bimetallic oxide core-shell structure enhances Pd-Co interaction, weakening the Co-O bond.
• This structural modification facilitates the release of lattice oxygen, promoting C-H bond breaking.
• The Pd(PdO)/Co3O4@SiO2 catalyst demonstrates superior performance for low-temperature methane combustion.