Magnetic γ-Fe₂O₃@Ir Nanozyme for Molar-Level 5-Hydroxymethylfurfural Oxidation With Atmosphere Oxygen

Area of Science:

• Materials Science
• Green Chemistry
• Catalysis

Background:

• Direct conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is environmentally and economically advantageous.
• Nanozymes with oxidase-like activity offer potential for green oxidation reactions.

Purpose of the Study:

• To develop and characterize an iridium-coated γ-Fe2O3 core-shell nanozyme (γ-Fe2O3@Ir) for HMF oxidation.
• To evaluate the catalytic performance of the nanozyme using atmospheric oxygen as a green oxidant.

Main Methods:

• Preparation of γ-Fe2O3@Ir nanozyme via reduction of Ir3+ on γ-Fe2O3 surface.
• Structural characterization using XRD, HAADF-STEM, and elemental line-scan analysis.
• Catalytic oxidation of HMF to FDCA using atmospheric oxygen.

Main Results:

• The γ-Fe2O3@Ir nanozyme structure was confirmed.
• The nanozyme's magnetic property aids recovery and enhances oxygen affinity.
• Achieved near-quantitative conversion (98.5%) of HMF to FDCA.

Conclusions:

• The γ-Fe2O3@Ir nanozyme is an effective catalyst for green HMF oxidation.
• This method presents a sustainable route for FDCA production.
• The nanozyme's properties facilitate efficient and recoverable catalysis.