Department of Chemistry
Mesoporous chromia with ordered three-dimensional structure for the complete oxidation of toluene and ethyl acetate
Mesoporous chromia with ordered three-dimensional (3D) hexagonal polycrystalline structures were fabricated at 130, 180, 240, 280, and 350 °C in an autoclave through a novel solvent-free route using KIT-6 as the hard template. The as-obtained materials were characterized (by means of X-ray diffraction, transmission electron microscopy, N2 adsorption - desorption, temperature-programmed reduction, and X-ray photoelectron spectroscopy techniques)andtestedasacatalyst for thecomplete oxidation of toluene and ethyl acetate. We found that with a high surface area of 106 m 2/g and being multivalent (Cr3+, Cr5+, and Cr6+), the chromia (meso-Cr-240) fabricated at 240 °C is the best among the five in catalytic performance. According to the results of the temperature-programmed reduction and X-ray photoelectron spectroscopy investigations, it is apparent that the coexistence of multiple chromium species promotes the low-temperature reducibility of chromia. The excellent performance of meso-Cr-240 is because of good 3D mesoporosity and low-temperature reducibility as well as the high surface area of the chromia. The combustion follows a first-order reaction with respect to toluene or ethyl acetate in the presence of excess oxygen, and the corresponding average activation energy is 79.8 and 51.9 kJ/mol, respectively, over the best-performing catalyst. © 2009 American Chemical Society.
Source Publication Title
Environmental Science and Technology
American Chemical Society
Xia, Yunsheng, Hongxing Dai, Haiyan Jiang, Jiguang Deng, Hong He, and Tong Au Chak. "Mesoporous chromia with ordered three-dimensional structure for the complete oxidation of toluene and ethyl acetate." Environmental Science and Technology 43.21 (2009): 8355-8360.