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Three-dimensionally ordered mesoporous Cr2O3 (meso-Cr2O3) and its supported Au, Pd, and Au-Pd (0.90 wt% Au/meso-Cr2O3, 1.00 wt% Pd/meso-Cr2O3, and xAu(1)Pd(2)/ineso-Cr2O3 (x = 0.50-1.95 wt) catalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected reduction methods, respectively. Physicochemical properties of the samples were characterized by means of numerous techniques, and their catalytic activities were evaluated for the oxidation of toluene. It is found that the meso-Cr2O3 with a high surface area of 74 m(2)/g was rhombohedral in crystal structure and the noble metal nanoparticles (NPs) with a size of 2.9-3.7 nm were uniformly dispersed on the surface of meso-Cr2O3. The 1.95Au(1)Pd(2)/meso-Cr2O3 sample performed the best: the T-10%, T-50%, and T-90% (temperatures required for achieving toluene conversions of 10, 50, and 90%) were 87,145, and 165 degrees C at a space velocity of 20,000 mL/(g h), respectively, and the apparent activation energy was the lowest (31 kJ/mol) among all of the samples. The effect of moisture on the catalytic activity of the 1.95Au(1)Pd(2)/meso-Cr2O3 sample was also examined. It is concluded that the excellent catalytic performance of 1.95Au(1)Pd(2)/meso-Cr2O3 was associated with its small Au Pd particle size, high adsorbed oxygen species concentration, good low temperature reducibility, and strong interaction between Au Pd NPs and meso-Cr2O3. (C) 2016 Elsevier Inc. All rights reserved.
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来源 :
MICROPOROUS AND MESOPOROUS MATERIALS
ISSN: 1387-1811
年份: 2016
卷: 224
页码: 311-322
5 . 2 0 0
JCR@2022
ESI学科: MATERIALS SCIENCE;
ESI高被引阀值:305
中科院分区:2