Piezocatalytic oxidation of 5-hydroxymethylfurfural to 5-formyl-2-furancarboxylic acid over Pt decorated hydroxyapatite

Selective oxidation of 5-hydroxymethylfurfural (HMF) to 5-formyl-2-furancarboxylic acid (FFCA) is a critical reaction for producing value-added chemicals from biomass. The challenge for this reaction is to develop an efficient catalytic process that can be conducted under mild conditions. Herein, we first propose piezocatalytic HMF oxidation using a Pt decorated hydroxyapatite (HAP) piezocatalyst (Pt/HAP). The introduction of Pt on HAP creates an interfacial electric field. The couple of nonlocal piezoelectric field and localized interfacial electric field greatly promotes both the bulk and surface charges transfer. Moreover, Pt not only promotes the separation of piezo-induced charges but also activates oxygen molecules and organic functional groups of the substrates. Compared with pristine HAP, Pt/HAP exhibits outstanding piezocatalytic activity, which reached 96% HMF conversion and 70% FFCA yield in 2 h under room temperature. A wide range of aldehydes and alcohols, such as fatty aldehydes, furan aldehydes, fatty alcohols, and ethylene glycol, were all oxidized to carboxylic acids. This work provides a novel method on utilizing piezocatalysis for biomass conversion.

Automated summary

In this study, a novel method of selective oxidation of 5-hydroxymethylfurfural (HMF) using a piezocatalyst was proposed. The Pt decorated hydroxyapatite (HAP) showed outstanding piezocatalytic activity, achieving high conversion and yield of value-added chemicals from biomass. This work provides a new approach for biomass conversion using piezocatalysis.