Screening of catalysts for the oxidative dehydrogenation of ethyl lactate to ethyl pyruvate, and optimization of the best catalysts

Article abstract of DOI:10.1016/j.apcata.2020.117619

This study reports on a new industrial gas-phase process to produce ethyl pyruvate, using the oxidative dehydrogenation of ethyl lactate. In an initial approach, twenty catalysts were screened under reaction conditions required for industrial applications. When evaluated in terms of their maximum selectivity to ethyl pyruvate and their productivity, the best catalyst was found to be a phosphomolybdic polyoxometalate, with iron counter-cations: FePMo12O40. To improve this catalyst, a study was carried out by including cesium counter-cations. The new catalysts exhibited higher yields because of higher Mo active surface site density related to higher specific surface area and although their intrinsic activity was lower. Their ethyl pyruvate selectivity increased with iron content but never overpass that of FePMo12O40. These results are explained in terms of changes in structure and iron counteraction coordination leading or not to electron exchange between iron and molybdenum and influencing the acidity of the catalyst's surface.