Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (02): 391-396.

• CATALYSIS AND SURFACE SCIENCE •

Influence of Ce/Cr Ratio on 2-CrOx Mixed Oxide Catalysts for the Catalytic Oxidation of 1,2-Dichloroethane

MENG Zhong-Hua, YANG Peng, ZHOU Ren-Xian

1. Department of Chemistry, Zhejiang University, Hangzhou 310028, P. R. China
• Received:2012-10-15 Revised:2012-12-06 Published:2013-01-14
• Supported by:

The project was supported by the National Natural Science Foundation of China (21177110), Ministry of Science and Technology of China (2011AA03A406), and Program for Zhejiang Leading Team of Science and Technology Innovation, China.

Abstract:

CeO2, Cr2O3, and CeO2-CrOx mixed oxides with molar ratios of Ce to Cr of 9/1, 4/1, 2/1, 1/1, 1/2, 1/4, and 1/8 were prepared by coprecipitation. The catalytic performance of 1,2-dichloroethane (DCE) decomposition was evaluated on all the catalysts. The results indicate that CeO2-CrOx mixed oxides with different Ce/Cr molar ratios showed higher performance for the removal of DCE compared with pure CeO2. The CeO2-CrOx mixed oxide with Ce/Cr molar ratio of 2/1 exhibited the highest catalytic activity of the samples, generating only small amounts of chlorinated by-products during the decomposition of DCE. The selectivity for HCl decreased as the molar ratio of Ce to Cr decreased. The catalysts were characterized by N2 adsorption/desorption, X-ray diffraction (XRD), UV-Raman spectroscopy, hydrogen temperatureprogrammed reduction (H2-TPR), and ammonia temperature-programmed desorption (NH3-TPD) to study the effect of the Ce/Cr molar ratio on the physicochemical performance of the catalysts. An appropriate molar ratio of Ce to Cr formed a more stable Ce-Cr-O solid solution, which increased the mobility of reactive oxygen species, oxidative ability, surface acid content and the ratio of strong acidity, promoting the adsorption, activation and deep oxidation of DCE.

MSC2000:

• O643