Liquid-phase oxidation of ethyl lactate to pyruvate over suspended oxide catalysts

Oxidation of ethyl lactate to pyruvate was carried out in the liquid-phase at 130°C in the presence of the oxides of various group IV to VI elements as candidate catalysts. Optimized reaction conditions with TiO 2 as a probe catalyst followed by comparative reaction studies for catalyst screening showed TiO 2 , ZrO 2 , and SnO 2 (+SnO) to be highly selective catalysts for giving pyruvate. Effects of temperature, oxygen pressure, solvents, and catalyst requirements are described. XPS and XRD patterns are given for a binary oxide, SnO 2 -MoO 3 , which showed excellent activity in favor of pyruvate.