Au-Assisted CHO Formation Promotes O₂ Activation for HCHO Oxidation over Au/Co₃O₄

Area of Science:

• Heterogeneous Catalysis
• Surface Chemistry
• Computational Materials Science

Background:

• Formaldehyde (HCHO) oxidation is crucial for air purification and chemical synthesis.
• Single-atom catalysts (SACs) offer high efficiency and selectivity.
• Understanding reaction mechanisms on SACs is key to designing better catalysts.

Purpose of the Study:

• To systematically investigate the HCHO oxidation pathway on Au/Co3O4 SACs.
• To identify the most stable configuration and reaction mechanism.
• To elucidate the promotional role of gold in the catalytic process.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Ab initio thermodynamics.
• Electronic structure analysis.

Main Results:

• Identified the most stable configuration: Au substituting a tetrahedral Co atom.
• Detailed the reaction pathway: HCHO adsorption, C-H cleavage, O2 activation, and COOH* decomposition.
• Demonstrated Au's dual role: lowering C-H dissociation barrier and facilitating O2 activation via CHO* intermediate.

Conclusions:

• Au significantly enhances HCHO oxidation on Co3O4 SACs.
• The intermediate CHO* plays a critical role in facilitating O2 activation.
• Provides insights for designing high-performance single-atom catalysts.