Fe-ZSM-5 catalysts modified by Cu and Ce by aqueous solution ion-exchange and incipient wetness impregnation methods were tested in the selective catalytic reduction of NO_(x) with NH_(3).A variety of characterization...Fe-ZSM-5 catalysts modified by Cu and Ce by aqueous solution ion-exchange and incipient wetness impregnation methods were tested in the selective catalytic reduction of NO_(x) with NH_(3).A variety of characterization techniques(NH_(3)-SCO,BET,XRD,XPS,UV-Vis,NH_(3)-TPD,H_(2)-TPR)were used to explore the changes of the active sites,acid sites and pore structure of the catalyst.It was found that the dispersion of active Cu species and Fe species had great influences on the catalytic activity in the whole catalytic process.The Cu doping into the Fe-ZSM-5 catalyst produced new active species,isolated Cu ions and CuO particles,resulting in the improved low-temperature catalytic activity.However,the NH_(3) oxidation was enhanced,and part of the Fe^(3+)active sites and more Brønsted acidic sites in the catalyst were occupied by Cu species,which causes the decrease of the high-temperature activity.The recovery of hightemperature activity could be attributed to the recovery of active Cu species and Fe species promoted by Ce and the promotion of active species dispersion.The results provide theoretical support for adjusting the active window of Febased SCR catalyst by multi-metal doping.展开更多
With the rapid development of modem industry and increase of consumption of the coal, petroleum and natural gas etc., emission of nitrogen oxide （NOx） from flue gas has air environment quality worsen day by day. Thi...With the rapid development of modem industry and increase of consumption of the coal, petroleum and natural gas etc., emission of nitrogen oxide （NOx） from flue gas has air environment quality worsen day by day. This research work is experimental study on removal low concentration NOx of flue gas by using solid absorbents. The experiment result shown that denification rate by modified activated carbon is higher than that of modified zeolite and rectorite. Average denitrification rate is 65.47% and maximum denitrification rate is 95.82% for activated carbon; average denitrification rate is respectively as 43.29% and 36.18%, maximum denitrification rate is respectively as 87.51% and 79.47% for modified zeolite and rectorite. Experiment results indicated that NO adsorption process of activated carbon can be described by Freudlich adsorption mode, K=0.143 and n=2.842 and Freudlich adsorption isotherm equation is： q = 0.143MO^0.3519.展开更多
基金Project(51906089)supported by the National Natural Science Foundation of ChinaProject(NELMS2018A18)supported by the National Engineering Laboratory for Mobile Source Emission Control Technology,China+1 种基金Project(XNYQ2021-002)supported by the Provincial Engineering Research Center for New Energy Vehicle Intelligent Control and Simulation Test Technology of Sichuan,ChinaProject(GY2020016)supported by the Zhenjiang City Key R&D Program,China。
文摘Fe-ZSM-5 catalysts modified by Cu and Ce by aqueous solution ion-exchange and incipient wetness impregnation methods were tested in the selective catalytic reduction of NO_(x) with NH_(3).A variety of characterization techniques(NH_(3)-SCO,BET,XRD,XPS,UV-Vis,NH_(3)-TPD,H_(2)-TPR)were used to explore the changes of the active sites,acid sites and pore structure of the catalyst.It was found that the dispersion of active Cu species and Fe species had great influences on the catalytic activity in the whole catalytic process.The Cu doping into the Fe-ZSM-5 catalyst produced new active species,isolated Cu ions and CuO particles,resulting in the improved low-temperature catalytic activity.However,the NH_(3) oxidation was enhanced,and part of the Fe^(3+)active sites and more Brønsted acidic sites in the catalyst were occupied by Cu species,which causes the decrease of the high-temperature activity.The recovery of hightemperature activity could be attributed to the recovery of active Cu species and Fe species promoted by Ce and the promotion of active species dispersion.The results provide theoretical support for adjusting the active window of Febased SCR catalyst by multi-metal doping.
文摘With the rapid development of modem industry and increase of consumption of the coal, petroleum and natural gas etc., emission of nitrogen oxide （NOx） from flue gas has air environment quality worsen day by day. This research work is experimental study on removal low concentration NOx of flue gas by using solid absorbents. The experiment result shown that denification rate by modified activated carbon is higher than that of modified zeolite and rectorite. Average denitrification rate is 65.47% and maximum denitrification rate is 95.82% for activated carbon; average denitrification rate is respectively as 43.29% and 36.18%, maximum denitrification rate is respectively as 87.51% and 79.47% for modified zeolite and rectorite. Experiment results indicated that NO adsorption process of activated carbon can be described by Freudlich adsorption mode, K=0.143 and n=2.842 and Freudlich adsorption isotherm equation is： q = 0.143MO^0.3519.
