One-pot synthesis of CNT-SAPO-34 composite supported copper and cerium catalysts with excellent surface resistance to SO_(2) and H_(2)O in NH_(3)-SCR

CuCe/CNT_(x)-SAPO-34(x=0,0.5,1,2) with various CNT doping quantities were synthesized through the one-pot hydrothermal synthesis method using CNT and SAPO-34 as composite supporters.The selected CuCe/CNT_1-SAPO-34 catalyst exhibits remarkable SCR activity and high H_(2)O/SO_(2) resistance in a wide temperature range of 200-450℃.X-ray diffraction(XRD),N_(2) adsorption-desorption,scanning electron microscopy(SEM),X-ray photoelectro n spectroscopy(XPS),H_(2)-temperature programmed reduction(H2-TPR),and NH3-temperature programmed desorption(NH_(3)-TPD) were used to characterize the physiochemical structure,surface state of active sites reducibility,and surface acidity of the catalysts.The characterization results reveal that CuCe/CNT_1-SAPO-34 possesses a hierarchical structure,small particle size,high levels of surface Cu^(2+),Ce^(3+) and chemisorbed oxygen,enhanced reducibility,and suitable surface acidity.For comparison,CuCe/CNT_1-SAPO-34(P) mixed mechanically with CuCe/CNT_0-SAPO-34and CNT was investigated through the NH3-SCR with and without H_(2)O/SO_(2),it also displays lower resistance of H_(2)O and SO_(2) than CuCe/CNT_1-SAPO-34.The catalytic performance made CuCe/CNT_1-SAPO-34 a promising catalyst for the NO_(x) emission control from diesel vehicles.