Chinese Journal of Chemical Engineering, Vol.28, No.10, 2592-2599, 2020
Effect of Zr-doping on Pd/CexZr1-xO2 catalysts for oxidative carbonylation of phenol
Ce-Zr solid solution (CexZr1-xO2, CZO) was prepared by the citric acid sol-gel method. The CZO was then used as a support for Pd/CZO catalysts for the oxidative carbonylation of phenol to diphenyl carbonate. The Pd/CZO catalyst showed enhanced activity and diphenyl carbonate selectivity compared with the Pd/CeO2 catalyst. The catalytic performance of Pd/CZO was influenced by the calcination temperature of the CZO support. X-ray diffraction, scanning electron microscopy, N-2 adsorption-desorption measurements, X-ray photoelectron spectroscopy and H-2 temperature-programmed reduction measurements were used to investigate the effects of Zr doping and calcination temperature. The catalytic performance of Pd/CZO and Pd/CeO2 for the oxidative carbonylation of phenol was affected by several factors, including the specific surface area, Ce3+ and/or oxygen vacancy content, oxygen species type and Pd(II) content of the catalyst. All these properties were influenced by Zr doping and the calcination temperature of the CZO support. (C) 2020 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.