PdAg/CoFe2O4 Bimetallic Catalyst with High Selectivity for Glyceraldehyde in Glycerol Selective Oxidation Reaction

The catalytic oxidation of glycerol was investigated in assays with palladium-silver bimetallic nanoparticles (Pd-Ag) immobilized on cobalt ferrite (CoFe2O4). Bimetallic nanoparticles were prepared by the galvanic replacement method, immobilized on CoFe2O4 by wet impregnation. Bimetallic Pd-Ag nanoparticles with 35 wt.% Pd content effectively catalyzed the selective oxidation reaction of glycerol to glyceraldehyde. Catalytic oxidation was carried out at 60-80 degrees C for 2-4 h in an aqueous NaOH solution (NaOH:glycerol ratio = 4 mol:mol) under O2 pressure of 4 bar; the selectivity of glyceraldehyde reached 99.35% and the conversion of glycerol of 49.07% at a temperature of 60 degrees C and a reaction time of 2 h. Glyceric acid and traces of tartronic acid and mesoxalic acid were also detected. The catalyst was also very stable, showing activity up to 4 runs without significant loss of activity and selectivity.