Catalytic Conversion of Glycerol to Lactic Acid Over Hydroxyapatite-Supported Metallic Ni0 Nanoparticles.

Catalytic conversion of low-priced biomass glycerol to value-added lactic acid is an alternative route to the conventional fermentation process using sugar as the starting material. Nanosized hydroxyapatite-supported metallic Ni0 nanoparticles (Nix/HAP) prepared by the wetness chemical reduction method effectively catalyzed the conversion of high-concentrated glycerol (1.5-3 mol L-1) to lactic acid in a NaOH aqueous solution. The Nix/HAP catalysts exhibited higher catalytic activity for glycerol conversion to lactic acid than the sole metallic Ni0 nanoparticles. When the reaction was carried out over the Ni0.2/HAP catalyst with the initial glycerol and NaOH concentrations of 2.0 and 2.2 mol L-1 at 200 °C for 2 h, the selectivity of lactic acid reached 94.7% at the glycerol conversion of 92.1%.