Effect of tin on Ru-B/γ-Al2O3 catalyst for the hydrogenation of ethyl lactate to 1,2-propanediol Original Research Article

Amorphous Ru-B supported on γ-Al2O3 was prepared by a novel reductant impregnation method for the hydrogenation of ethyl lactate to 1,2-propanediol (PDO). The effects of tin on composition, physicochemical properties, thermal stability and reaction behavior of Ru-B/γ-Al2O3 catalyst were studied by using in situ XRD, TEM, H2-TPD, XPS and liquid phase hydrogenation of ethyl lactate. The Ru-B/γ-Al2O3 catalyst prepared by reductant impregnation showed good activity for hydrogenation of ethyl lactate. Addition of suitable amounts of tin (Sn/Ru atomic ratio of 7%) significantly increased the ethyl lactate conversion and the selectivity to 1,2-PDO; a selectivity to 1,2-PDO of 91.5% was obtained at ethyl lactate conversion of 90.7% under mild reaction conditions. The characterizations showed that addition of tin improved the dispersion and thermal stability of Ru-B significantly. The B/Ru ratio of the catalyst, the electron density of Ru, and the strength of hydrogen adsorption of the catalyst increased with increase of tin content over the range studied.