NiO and CoOx Promoted Pt Catalysts for Glycerol Oxidation
Two kinds of Pt/CeO2 catalysts supplemented with NiO or CoOx additives were synthesized by extractive pyrolytic method and tested in glycerol oxidation processes. It was found that only NiO additive promotes Pt/CeO2 catalysts activity and selectivity to glyceric acid. NiO promoted Pt catalysts activity depends on NiO composites' calcination temperature, oxygen partial pressure, initial NaOH concentration, as well as temperature. Glycerol conversion increases along with increased oxygen partial pressure from1 to 6 atm and along with decreased glycerol/Pt molar ratio from 5000 to 300. It was found that presence of base is significant in the glycerol oxidation processes over NiO promoted Pt/CeO2 catalysts, and optional NaOH initial concentration is 0.6 mol/L. The best yield of glyceric acid (68% was reached in the presence of 4.8wt%Pt/5wt%NiO/CeO2 (300 degC) catalyst, when temperature was elevated up to 70 degC.