Electron Structure Tuned Oxygen Vacancy-Rich AuPd/CeO₂ for Enhancing 5-Hydroxymethylfurfural Oxidation

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Efficient conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is crucial for sustainable chemical production.
• Catalyst design, particularly tailoring electronic structures, significantly impacts oxidation reactions involving molecular oxygen.
• Understanding metal-support interactions is key to developing high-performance catalysts.

Purpose of the Study:

• To design and synthesize highly active bimetallic AuPd/CeO2 catalysts for HMF oxidation to FDCA.
• To investigate the role of electronic structure and oxygen vacancies in catalytic performance.
• To elucidate the reaction mechanism using experimental data and density functional theory (DFT) calculations.

Main Methods:

• Synthesis of bimetallic AuPd/CeO2 catalysts via chemical reduction and photo-deposition.
• Acidic treatment of CeO2 to increase oxygen vacancy concentration.
• Characterization of catalysts and HMF oxidation performance evaluation at 80°C.
• Density Functional Theory (DFT) calculations to study electronic states and reaction mechanisms.

Main Results:

• AuPd/CeO2 catalysts exhibited excellent activity, achieving 99.0% yield of FDCA.
• Acidic treatment enhanced HMF adsorption and FDCA yield by increasing CeO2 oxygen vacancy concentration.
• DFT calculations confirmed that the electron-rich interfacial Au-Pd-CeO2 sites enhance molecular oxygen activation.
• A high FDCA formation rate of 13.21 mmol·g⁻¹·min⁻¹ was achieved.

Conclusions:

• The electronic state of interfacial sites is critical for catalyst performance in HMF oxidation.
• Electron-rich Au sites and increased oxygen vacancies in CeO2 promote efficient HMF conversion to FDCA.
• This work provides insights for designing advanced catalysts for selective oxidation reactions.