Study On The Preparation And SCR-DeNO_x Of Monolithic Catalyst By In-situ Technology

The TiO2 and TiO2-SiO2 coats were prepared by in-situ loading method,using cordierite as carrier,for improving the adhesion and dispersion of monolithic catalyst.The adhesion of the coats and the catalytic activity of the low-temperature catalyst of MnO2/TiO2-SiO2/cordierite and high-temperature catalyst of V2O5-WO3/TiO2-SiO2/cordierite were investigated.The coats were analysed by BET(specific surface area),XRD(X-ray diffraction),SEM(scanning electron microscope),EDS(Energy dispersive spectrometer),NH3-TPD(NH3-temperature programmed desorption)and adhesion text.The results show that the coat prepared by in-situ loading method has good adhesion,the Ti02 can be well dispersed and it can be enhanced by adding SiO2.Furthermore,the added SiO2 improves the specific surface area of the coat and the strength of the acid.The MnOx prepared by the in-situ deposited method was also well dispersed on the surface of the coat,its main crystalline phase was Mn2O3,its particle diameter was between 0.5 to 2.0 ?m.The catalytic activity measurement results show that MnOx monolithic catalysts has good activity,the catalytic behavior can reached to 90%on 180? when the coat loading is above 15wt%and the MnOx loading is 5wt%.The added Si02 can improve the catalytic behavior,when the temperature is above 200?.Otherwise,the V2O5-WO3/Ti02/cordierite and V2O5-WO3/TiO2?SiO2/cordierite monolithic catalysts were prepared by the same loading technology,and two methods of active phase loading were studied,the loading active phase before calcining(D)method and the loading active phase before drying(C)method.The catalytic activity measurement results show that V205-WO3/TiO2-SiO2/cordierite(C)monolithic catalyst has good activity,the catalytic behavior can remain higher than 90%between 300?340?.The SEM results show that the W03 crystalline phases was well dispersed by(C)method,however,it was fused with coat by(D)method.The added SiO2 can improve the dispersion of the WO3 crystalline phases and the strength of the acid.