Perovskite supported catalysts for the selective oxidation of glycerol to tartronic acid

Exceptional selectivity of LaMnO₃ perovskite supported Au catalysts for the oxidation of glycerol to the dicarboxylate tartronic acid is reported. Through using monometallic Au, Pt or bimetallic Au:Pt nanoparticles the tartronic acid yield could be altered significantly, with a maximum yield of 44% in 6 h with Au/LaMnO₃ and 80% within 24 h. These LaMnO₃ supported catalysts were compared with conventionally TiO₂ supported catalysts, which at comparable reaction conditions produced lactic acid, via a dehydration pathway, in high yield and a maximum tartronic acid yield of only 9% was observed. The LaMnO₃ catalysts produced minimal lactic acid regardless of the supported metal, showing that the support structure influences the prevalence of dehydration and oxidation pathways. The choice of metal nanoparticle influenced product selectivity along the oxidation pathway for both LaMnO₃ and TiO₂ supported catalysts. Au catalysts exhibited a higher selectivity to tartronic acid, whereas AuPt catalysts produced glyceric acid and Pt catalysts produced predominantly C-C scission products.