| Lots of exhausts coming from the petrol-chemical plants and automobiles have induced many troublesome environmental problems. CO and VOCs are the main exhausts. The developed countries have made many strict effluent standards to control the discharge of CO and VOCs. Catalytic combustion has been recognized as one of the most important technologies to destroy CO and VOCs at low temperature. This method has many advantages such as low temperature required for combustion ignition, high energy efficiency, and avoiding the formation of toxic byproducts. The mesoporous silica material SBA-15 may be a promising new type of porous support for catalytic combustion, due to its high surface area, highly ordered pore structure and uniform pore size distribution. Comparing to the conventional catalyst, the monolithic catalyst has distinct advantages, such as low-pressure drop, favorable heat and mass transfer properties and minimum axial dispersion. Thus for the reactions with high space velocity and heat exchange, the monolithic catalysts have a promising application.In this paper, A series of new type catalysts were prepared for the oxidation of low concentration CO and toluene. The structure and the catalytic activity of the catalysts were investigated. The CuxCe1-xO2-x/SiO2, CuxCe1-x/SBA-15 supported catalysts and CuxCe1-xO2-x/SBA-15/FeCrAl, CuxCe1-xO2-x/SBA-15/cordierite monolithic catalysts were prepared. Their catalytic performances for the catalytic combustion of CO were tested and the activation energies were calculated. CuxCo1-x/SBA-15 supported catalysts and CuxCo1-x/Al2O3/FeCrAl,CuxCo1-x/Al2O3/cordierite monolithic catalysts were prepared and their catalytic performances for the catalytic combustion of toluene were tested. The structure of the catalysts was characterized by XRD, N2 adsorption-desorption, HRTEM, XPS, SEM and H2-TPR. The relationship between the catalytic performance and the structure of the catalysts was studied. The main results are listed as follows:For the CuxCe1-xO2-x/SiO2 series catalysts,25%Cu0.5Ceo.5O1.5/SiO2 catalyst showed the best activity and CO could be totally oxidized at 169℃when GHSV=34,000h-1. For the catalysts with the same Cu/Ce molar ratios, the main phase was CuO-CeO2 solid solution when the content of Cuo.5Ceo.501.5 was low, while the CuO phase could be found at higher Cuo.5Ceo.5O1.5 content. For the catalysts with different Cu/Ce molar ratios, CuO was the main phase when the content of Cu is high, while the main phases were CuO-CeO2 solid solution and CeO2 when the content of Cu is low.For the CuxCe1-xO2-x/SBA-15 catalysts,30%Cuo.5Ceo.5O1.5/SBA-15 catalyst with the lowest activation energy 70.6 kJ/mol showed the best activity and CO could be totally oxidized at 156℃when GHSV=48,000h-1. For the catalysts with the same Cu/Ce molar ratios, the main phase was CuO-CeO2 solid solution when the content of Cu0.5Ce0.5O1.5 was less than 10%, while the CuO phase could be found at higher Cu0.5Ce0.5O1.5 content. For the catalysts with different Cu/Ce molar ratios, CuO was the main phase when the content of Cu is high, while the main phases were CuO-CeO2 solid solution and CeO2 when the content of Cu is low.For the CuxCe1-xO2-x/SBA-15/FeCrAl monolithic catalysts, 50%Cu0.5Ce0.5O1.5/SBA-15/FeCrAl catalyst showed the best activity and CO could be totally oxidized at 142℃when GHSV=36,000ml/g·h. For the catalysts with the same Cu/Ce molar ratios, the CuO phase only could be found when the content of Cu0.5Ce0.5O1.5 was more than 40%. The 50%Cu0.7Ce0.301.3/SBA-15/FeCrAl catalyst showed an excellent stabile performance, the activity remained the same 97% CO conversion during the 1306 h of stability reaction,For the CuxCe1-xO2-x/SBA-15/cordierite series catalysts, 50%Cu0.5Ce0.501.5/SBA-15/cordierite catalyst showed the best activity and CO could be totally oxidized at 120℃when GHSV=33,00Oml/g·h. For the catalysts with the same Cu/Ce molar ratios, the CuO phase only could be found when the content of Cu0.5Ce0.5O1.5 was more than 40%.For the CuxCo1-x/SBA-15 supported catalysts,40%Cu0.25Co0.75/SBA-15 catalyst showed the highest catalytic activity. Toluene can be completely oxidized at 285℃with a GHSV of 34,000 ml/g·h. The loading of Cu, Co affects the surface area, pore volume and average pore diameter of SBA-15, but the mesoporous structure was maintained. The results indicated that Cu-Co-O compound was observed when the Cu content was low. The peaks of CuO were observed when the Cu content was high.For the CuxCo1-x/Al2O3/FeCrAl series catalysts, Cuo.5Coo.5/Al203/FeCrAl catalyst showed the best activity and toluene could be totally oxidized at 357℃when GHSV=56,380ml/g-h. The XPS results showed that both Co2+ and Co3+existed in the obtained monolithic catalysts, and Cu existed mainly as Cu2+species. When x<0.5, the introduction of copper oxide improved the reducibility of the cobalt oxide and enhanced the catalytic activity of the catalysts.For the CuxCo1-x/Al2O3/cordierite series catalysts, Cu0.5Co0.5/Al203/cordierite catalyst showed the best activity and toluene could be totally oxidized at 315℃when GHSV=56,380ml/g·h. When x was more than 0.5, the CuO phase could be found.
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