TY - JOUR
T1 - Mesoporous chromia with ordered three-dimensional structures for the complete oxidation of toluene and ethyl acetate
AU - Xia, Yunsheng
AU - Dai, Hongxing
AU - Jiang, Haiyan
AU - Deng, Jiguang
AU - He, Hong
AU - AU, Chak Tong
N1 - This work was supported by the PHR200907105 and KZ200610005004 projects. C.T.A. thanks RGC, HKSAR for financial support (Grant HKBU 200106).
PY - 2009/11/1
Y1 - 2009/11/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=70350786683&partnerID=8YFLogxK
U2 - 10.1021/es901908k
DO - 10.1021/es901908k
M3 - Journal article
C2 - 19924969
AN - SCOPUS:70350786683
SN - 0013-936X
VL - 43
SP - 8355
EP - 8360
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 21
ER -