Stabilized hydrogenolysis of glycerol to 1,3-propanediol over Mg modified Pt/WOx–ZrO2 catalysts

Abstract

Stable hydrogenolysis of glycerol to value-added 1,3-propanediol (1,3-PDO) over WOx-containing catalyst is a serious challenge in aqueous solution. Because the tungsten oxide can interact with the H+ to form H2WO4 and dissolve to deactivate for catalyst under hydrothermal condition. Therefore, we prepared stable Pt/WOx–ZrO2 catalysts modified with Mg by the method of impregnation–calcination. The Raman and H2-TPR spectra demonstrate that the polymerization degree of WOx on the catalyst surface could be effectively reduced by introducing Mg. The formation of smaller WOx species are conducive to the formation of 1,3-PDO. Among them, the Pt/0.66Mg/WOx–ZrO2 achieved the maximum 62.4% selectivity of 1,3-PDO. In addition, the Pt/WOx–ZrO2 catalyst was deactivated due to leaching of tungsten from ZrO2 surface into the aqueous solution. Introduction of Mg can inhibit the leaching of tungsten and greatly improve the stability in hydrogenolysis of glycerol. So the Pt/0.50Mg/WOx–ZrO2 catalyst showed excellent stability with 56% conversion and 33% yield of 1,3-PDO under an extremely long 400 h time-on-stream.