Defect-Rich Regulatory Activity Strategy: Disordered Structure for Enhanced Catalytic Interfacial Reaction of...

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Amorphous materials offer abundant defect sites for efficient catalysis.
• Defect engineering in amorphous catalysts is crucial for degrading volatile organic compounds (VOCs).
• Systematic studies on amorphous catalysts for VOC degradation are limited.

Purpose of the Study:

• To synthesize novel amorphous CeMn catalysts with abundant defects.
• To investigate the catalytic performance of these materials for chlorinated VOCs (Cl-VOCs).
• To elucidate the structure-activity relationship and reaction mechanism.

Main Methods:

• Hydrothermal synthesis for amorphous CeMn catalysts.
• Experimental characterizations (e.g., XRD, TEM, XPS).
• Density Functional Theory (DFT) calculations.
• ¹⁸O isotope kinetic experiments.

Main Results:

• Amorphous CeMn catalysts with abundant defects were successfully prepared.
• Ce doping induced MnO₂ lattice distortion, forming amorphous structures and defect sites.
• CeMn_0.16 demonstrated high efficiency in degrading chlorobenzene (CB) at 200°C, outperforming MnO₂.
• High CO₂ yields and inorganic chlorine selectivity were observed.
• The reaction followed the Mars-van Krevelen (MVK) mechanism, with oxygen vacancies enhancing oxygen activation and migration.
• Mn⁴⁺ was identified as the primary active site, with ROS and Ce⁴⁺-Mn³⁺ interfaces accelerating the catalytic cycle.

Conclusions:

• Amorphous CeMn catalysts are effective for Cl-VOC degradation under mild conditions.
• The abundant defect sites, particularly oxygen vacancies, are key to the enhanced catalytic activity.
• The study provides a new avenue for designing defect-rich amorphous catalysts for environmental applications.