Effect of Pd loading and precursor on the catalytic performance of Pd/WO 3–ZrO 2 catalysts for selective oxidation of ethylene

Abstract

The structure and properties of Pd/WO 3–ZrO 2 (W/Zr = 0.2) catalysts with different Pd loadings and precursors were investigated. The results indicate that Pd/WO 3–ZrO 2 prepared from a PdCl 2 precursor was optimum for high activity and selectivity. Moreover, ethylene conversion increased with the Pd loading. The structure and nature of the catalysts were characterized using X-ray diffraction, BET N 2 adsorption, H 2 temperature-programmed reduction and H 2 pulse adsorption techniques. The results reveal that the higher catalytic performance of Pd/WO 3–ZrO 2 prepared from PdCl 2 could be related to the formation of polytungstate species and the existence of well-dispersed Pd particles.