The fabrication of BaTiO3 supported AuPd nanoparticles for selective oxidation of 1,2-propanediol to lactic acid

BACKGROUND The oxidation of 1,2-propanediol under alkaline conditions in the presence of a heterogeneous catalyst can be tailored to the formation of lactic acid, an important commodity chemical. In the present study, BaTiO 3 supported bimetallic AuPd nanoparticles was fabricated by sol-immobilized method and investigated by different characterizations. The optimum operating parameters of 1,2-propanediol catalytic oxidation were explored via the combination of single factor experiment and response surface methodology. RESULTS The high lactic acid yield of 81.4% can be obtained under optimum operating conditions (106 °C, 1.1 MPa O 2 pressure, and NaOH/1,2-PDO molar ratio of 3.0). The results of single factor experiment indicated that selectivity to lactic acid decreased with prolonging the reaction time, but increasing the temperature, NaOH concentration and O 2 pressure appeared to decrease the lactic acid selectivity after an initial increase. Reaction kinetics indicated that the value of Ea was 39.2 kJ·mol −1 over AuPd/BaTiO 3 catalyst. After five runs, the AuPd/BaTiO 3 catalyst stills retained high activity. CONCLUSION The AuPd/BaTiO 3 catalyst exhibited a good catalytic activity for this selective oxidation while the coalescence of Au and Pd nanoparticles can enhance the selectivity to lactic acid. NaOH/1,2-PDO molar ratio imposed an extremely comparable impact on lactic acid yield. The mutual interactions between reaction temperature and NaOH/1,2-PDO molar ratio, as well as NaOH/1,2-PDO molar ratio and pressure, were of vital significance. © 2021 Society of Chemical Industry (SCI).