Preparation of SCR catalyst carrier by APCVD and sol-gel technologies

摘要

TiO_2 has been loaded on cordierite porous ceramic to prepare the SCR catalyst carrier by using both APCVD and sol-gel technology. In APCVD method, TiCL_4 and O_2 were used as reaction precursor. TICl_4 was gasified by using N_2 as carrier gas which was controlled to 500sccm. Its reaction temperature and reaction time were limited to 773K and 30min respectively. The physical properties, SEM and SEM-EDX of the TiO_2-cordierite carrier and the properties of SCR catalysts prepared by these carriers have been tested. The tests showed that TiO_2 loaded by APCVD method were of graininess shape and even accumulation. The loading rate of TiO_2 and the specific area of carrier sample were increased 114% and 21% respectively comparing with sol-gel technology. In the result of sol-gel method, the maximal difference of Ti content was 66.92%, while the result of APCVD method was 18.89%. It demonstrated that TiO_2 was uniformly attached with the cordierite ceramic by using APCVD method, which would ensure more active ingredients well loaded on the TiO_2-cordierite carrier. This difference made the denitrification ratio of catalyst prepared by APCVD method was 8.1% higher than that of catalyst prepared by sol-gel method.