Air contamination caused by the ammonia slip phenomenon has gradually captured the researcher’s extensive attention.An effective strategy for controlling fugitive NH_(2)is critical to improving the air quality and li...Air contamination caused by the ammonia slip phenomenon has gradually captured the researcher’s extensive attention.An effective strategy for controlling fugitive NH_(2)is critical to improving the air quality and living environment.In the present work,CuO_(x)/La_(2)Ce_(2)O_(7)composite as a potential candidate catalyst is synthesized through the electrostatic adsorption method for the selective catalytic oxidation(SCO_(2))of NH_(2)to N.The 5%Cu Ox/La_(2)Ce_(2)O_(7)exhibits the best catalytic activity(T=243℃)and ammonia conversion efficiency.The improvement of performance is mainly attributed to the superficial connection of[Ce-O-Cu],which enhances the capturing ability of ammonia molecule and accelerates the dissociating efficiency of N–H bonding for Nevolution,simultaneously.This work provides a facile method to synthesis pyrochlore-like composite catalyst of NH_(2)-SCO_(2) for solving the problem of ammonia slip pollution in the future.展开更多
Formaldehyde(HCHO)is a common indoor pollutant that is detrimental to human health.Its efficient removal has become an urgent demand to reduce the public health risk.In this work,Ag-MnO_(x)-based catalysts were prepar...Formaldehyde(HCHO)is a common indoor pollutant that is detrimental to human health.Its efficient removal has become an urgent demand to reduce the public health risk.In this work,Ag-MnO_(x)-based catalysts were prepared and activated under different atmosphere(i.e.,air,hydrogen(H_(2))and carbon monoxide(CO))for efficient oxidation of HCHO.The catalyst activated with CO(Ag/Mn-CO)displayed the highest activity among the tested samples with 90% conversion at 100℃ under a gas space velocity of 75,000 mL/(g_(cat)·hr).Complementary characterizations demonstrate that CO reduction treatment resulted in synergically regulated content of surface oxygen on support to adsorb/activate HCHO and size of Ag particle to dissociate oxygen to oxidize the adsorbed HCHO.In contrast,other catalysts lack for either abundant surface oxygen species or metallic silver with the appropriate particle size,so that the integrate activity is limited by one specific reaction step.This study contributes to elucidating the mechanisms regulating the oxidation activity of Ag-based catalysts.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51771131)the Postdoctoral Research Foundation of China(No.2020M670676)+4 种基金the National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2019B01)the CATARC(Tianjin)Automotive Engineering Research Institute Youth Innovation Fund Project(No.S1921506)the Science and Technology Directorate Project of Tianjin City(No.19YFZCSF00960)CATARC(Tianjin)Central Guide Project(No.21243409)CATARC(Tianjin)Youth Science and Technology Talents Project(No.21226303)。
文摘Air contamination caused by the ammonia slip phenomenon has gradually captured the researcher’s extensive attention.An effective strategy for controlling fugitive NH_(2)is critical to improving the air quality and living environment.In the present work,CuO_(x)/La_(2)Ce_(2)O_(7)composite as a potential candidate catalyst is synthesized through the electrostatic adsorption method for the selective catalytic oxidation(SCO_(2))of NH_(2)to N.The 5%Cu Ox/La_(2)Ce_(2)O_(7)exhibits the best catalytic activity(T=243℃)and ammonia conversion efficiency.The improvement of performance is mainly attributed to the superficial connection of[Ce-O-Cu],which enhances the capturing ability of ammonia molecule and accelerates the dissociating efficiency of N–H bonding for Nevolution,simultaneously.This work provides a facile method to synthesis pyrochlore-like composite catalyst of NH_(2)-SCO_(2) for solving the problem of ammonia slip pollution in the future.
基金supported by the National Natural Science Foundation of China(Nos.22025604,22106171,21936005,and 21976196)the Jinan“20 Universities”Funding Project(No.2020GXRC027)。
文摘Formaldehyde(HCHO)is a common indoor pollutant that is detrimental to human health.Its efficient removal has become an urgent demand to reduce the public health risk.In this work,Ag-MnO_(x)-based catalysts were prepared and activated under different atmosphere(i.e.,air,hydrogen(H_(2))and carbon monoxide(CO))for efficient oxidation of HCHO.The catalyst activated with CO(Ag/Mn-CO)displayed the highest activity among the tested samples with 90% conversion at 100℃ under a gas space velocity of 75,000 mL/(g_(cat)·hr).Complementary characterizations demonstrate that CO reduction treatment resulted in synergically regulated content of surface oxygen on support to adsorb/activate HCHO and size of Ag particle to dissociate oxygen to oxidize the adsorbed HCHO.In contrast,other catalysts lack for either abundant surface oxygen species or metallic silver with the appropriate particle size,so that the integrate activity is limited by one specific reaction step.This study contributes to elucidating the mechanisms regulating the oxidation activity of Ag-based catalysts.
