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 cat...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.展开更多
SAPO-34,SAPO-5/34 based catalysts doped with Cu,Ce as active components were synthesized via a one-pot hydrothermal method by using different amounts of additive(a-cellulose),and their catalytic activities were measur...SAPO-34,SAPO-5/34 based catalysts doped with Cu,Ce as active components were synthesized via a one-pot hydrothermal method by using different amounts of additive(a-cellulose),and their catalytic activities were measured for selective catalytic reduction(SCR) of NO with NH3.The synthesized Cu-Ce co-doped products switch from cubic SAPO-34,to flower-like aggregated SAPO-5/34,hybrid crystal SAPO-5/34,and finally to spherical aggregated SAPO-34 with the increase of α-cellulose amount.The Cu-Ce co-doped SAPO-5/34 hybrid crystal structure catalysts with 0.75 mol ratios of C/P(Cu-Ce/SP-0.75)exhibit excellent NH_(3)-SCR activity with higher than 90% NOx conversion in the temperature range of 180-450℃,at WHSV of 20000 mL/(g·h).Furthermore,the catalyst displays outstanding sulfur resistance and NOX conversion maintains above 90% at 200-450℃ after adding 100 ppm of SO_(2).The characteristic results suggest that the high deNOX performance of Cu-Ce/SP-0.75 is due to the enhanced accessibility,abundant activity species,excellent redox property and high adsorptive and activated capacity for NH_(3).展开更多
基金supported by the Basic Science Research Project of Heilongjiang Provincial University,China (145109109)。
文摘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.
基金supported by the National Natural Science Foundation of China (51708309)Natural Science Foundation of Heilongjiang Province+1 种基金China (QC2017065)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province (UNPYSCT-2018106)。
文摘SAPO-34,SAPO-5/34 based catalysts doped with Cu,Ce as active components were synthesized via a one-pot hydrothermal method by using different amounts of additive(a-cellulose),and their catalytic activities were measured for selective catalytic reduction(SCR) of NO with NH3.The synthesized Cu-Ce co-doped products switch from cubic SAPO-34,to flower-like aggregated SAPO-5/34,hybrid crystal SAPO-5/34,and finally to spherical aggregated SAPO-34 with the increase of α-cellulose amount.The Cu-Ce co-doped SAPO-5/34 hybrid crystal structure catalysts with 0.75 mol ratios of C/P(Cu-Ce/SP-0.75)exhibit excellent NH_(3)-SCR activity with higher than 90% NOx conversion in the temperature range of 180-450℃,at WHSV of 20000 mL/(g·h).Furthermore,the catalyst displays outstanding sulfur resistance and NOX conversion maintains above 90% at 200-450℃ after adding 100 ppm of SO_(2).The characteristic results suggest that the high deNOX performance of Cu-Ce/SP-0.75 is due to the enhanced accessibility,abundant activity species,excellent redox property and high adsorptive and activated capacity for NH_(3).
