Au/Mg（OH）2:Highlyefficientforselectiveoxidationof1,2-propanedioltolacticacidwithmolecularoxygen

The catalytic oxidation of biomass-derived polyhydroxyl compounds provides an efficient and green route for biomass resource utility.Gold nanocrystals supported on Mg(OH)2 were synthesized by sol-immobilization method,characterized by XRD,TEM,UV-vis DRS,and tested in the selective oxidation of 1,2-propanediol to lactic acid.The gold particle size and the ratio of Au to 1,2-propanediol strongly influenced the catalytic activity.Over Au/Mg(OH)2 with the majority of gold particles concentrated in 14-18 nm,excellent catalytic performance with 94.4% conversion and 89.3% selectivity to lactic acid has been achieved under 0.3 MPa O2 at 60°C for 6 h.