Expediting CH₄ combustion process over Ni-Ce composite oxide catalysts via a modulator-assisted synthesis strategy

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Low-concentration methane combustion is crucial for environmental protection.
• Developing efficient and stable catalysts for methane oxidation remains a challenge.

Purpose of the Study:

• To controllably fabricate Ni-Ce composite oxide catalysts for low-concentration methane combustion.
• To investigate the role of modulators in tuning catalyst properties and performance.

Main Methods:

• Modulator-aided solvothermal synthesis using formic acid and terephthalic acid (1,4-BDC).
• Fabrication of Ce-Ni-BDC precursors to control nucleation and crystallization.
• Characterization of the derived Ni-Ce composite oxides.

Main Results:

• Tailored Ni-Ce catalysts exhibited smaller NiO and Ce_1-zNi_zO_2-δ particle sizes.
• Increased oxygen vacancy defects and interfaces were observed, enhancing oxygen transport.
• Improved capacity for H atom extraction and aerial O₂ activation was achieved.

Conclusions:

• The modulator-aided synthesis effectively controlled catalyst structure and properties.
• Enhanced redox cycling and active sites led to superior methane combustion activity.
• The developed catalyst demonstrated excellent reusability, stability, and moisture resistance.