Aqueous oxidation of 1,5-pentanediol to glutaric acid over Pt-based catalysts: mechanistic study and kinetic modeling

Aqueous oxidation of 1,5-pentanediol (1,5-PDO), a furfural-based intermediate, presents a sustainable pathway to synthesize glutaric acid (GA) for polyester industry. Kinetic analysis and mechanistic modeling for this reaction is indispensable for catalyst optimization and process scale-up. In this work, power law and modified Langmuir-Hinshelwood kinetic study confirmed a unique 2nd order kinetics on aqueous oxidation of 1,5-PDO over Pt-based catalysts. Notably, bimetallic PtAu/TiO 2 catalysts exhibited superior selectivity toward target carboxylic acids (5-hydroxyvaleric acid and GA) by facilitating oxidation of –CHO group in the key intermediate 5-hydroxypentanal compared to monometallic Pt/TiO 2 catalyst. Furthermore, a preliminary technoeconomic comparison with the fossil-based synthetic route was evaluated to highlight the advantage of bio-GA studied in this work. The outcome of kinetic modeling would provide useful information for optimizing cost-effective catalysts and process design in producing bio-derived dicarboxylic acids.