Selective Oxidation of 1,2-Propanediol to Lactic Acid over Different Supported Au, Pt and Pd Catalysts

Abstract

1,2-Propanediol selective oxidation with molecular oxygen in presence of heterogeneous catalyst is one of the most nature friendly 1,2-propanediol conversion methods. This work demonstrates Au, Pt and Pd containing catalysts’ activity and selectivity in a 1,2-propanediol oxidation process. The main product of the 1,2-propanediol catalytic oxidation was lactic acid, by-products were acetic and formic acids. It was found that Au based catalysts are best for 1,2-propanediol oxidation in alkaline water solutions. The best result was achieved using the 4.8wt%Au/Al2O3catalyst: selectivity by lactic acid was 94% with 1,2-propanediol conversion 100% (c0(1,2-propanediol) = 0.3 mol/L, P(O2) = 6 atm, n (1,2-propanediol)/n (Au) = 500, t = 60°C, c0(NaOH) = 1.5 mol/L).