Fuel cell stacks as the automotive power source can be severely poisoned by a trace amount of NOx in atmosphere,which makes it necessary to provide clean air for fuel cell vehicles.In this work,activating commercial a...Fuel cell stacks as the automotive power source can be severely poisoned by a trace amount of NOx in atmosphere,which makes it necessary to provide clean air for fuel cell vehicles.In this work,activating commercial activated carbons with K2CO3 for the large enhancement of NO capture was studied.K2CO3 modified activated carbons(K2CO3 ACs)were prepared by impregnating activate carbons in K2CO3 solution under ultrasound treatment,followed by temperature programmed baking at 800 oC.The dynamic NO flow tests on K2CO3 ACs at room temperature indicated that NO adsorption capacity reached the maximum(96 mg/g)when K2CO3 loading was 19.5 wt%,which corresponded to a specific surface area of 1196.1 m2/g and total pore volume of 0.70 cm3/g.The ten-fold enhancement of NO adsorption on K2CO3 ACs compared to the unimpregnated activated carbon was mainly attributed to the formation of potassium nitrite,which was confirmed by FTIR and temperature programmed desorption measurements.Regeneration tests of NO adsorption on the optimum sample revealed that 76%of the NO adsorption capacity could be remained after the fourth cycle.展开更多
s: Three kinds of Co sites,i.e. tetrahedral(Co[o]), cobalt cobalt sites and bulk Co3O4 are characterized by infrared spechoscopy of CO and NO adsothed on reduced and sueded Co/Al2O3 at room temperature.
The activities of neutral, anionic, and cationic Au（111）, Au（100）, surface towards NO adsorption have been studied by performing and Au（310） surfaces, as well as an Au adatom on Au（111） density functional theo...The activities of neutral, anionic, and cationic Au（111）, Au（100）, surface towards NO adsorption have been studied by performing and Au（310） surfaces, as well as an Au adatom on Au（111） density functional theory calculations. It was found that the activity of gold increases as the coordination number of the gold atoms decreases, and that the cationic surfaces are generally more active than the neutral and anionic surfaces. The activity of Au surfaces towards NO adsorption is attributable to the presence of low coordinated gold atoms and the concentration of positive charges on the surface. The results may enrich the understanding of NO adsorption on Au surfaces.展开更多
Thee adsorption of CO and NO on copper ion-exchanged zeolite Beta was investigated using IR method.It was found that the thermalvacuum pretreatment procedure could result in the reduction of Cu2+ions in zeolite Beta.T...Thee adsorption of CO and NO on copper ion-exchanged zeolite Beta was investigated using IR method.It was found that the thermalvacuum pretreatment procedure could result in the reduction of Cu2+ions in zeolite Beta.The adsorption of CO on Cu+sites in zeolite Beta closely follows Langmuir isotherm.Another Cu+species may form during the reaction between water and CO.The catalytic decomposition of NO on the zeolite was observed at room temperature,indicating that the decomposition reaction may occur between two coordinated NO ligands of the same dinitrosyhc complex.Furthermore,the appearance of two series of NO adsorption bands reveals that copper ions existing at different cation sites may have different effect on the adsorption and decomposition of NO molecules.展开更多
CMK-3 and C-FDU-15 samples were synthesized using hard-templating and evaporationinduced self-assembly(EISA)methods,respectively.The pore structures of CMK-3 and CFDU-15 as well as commercial activated carbon were cha...CMK-3 and C-FDU-15 samples were synthesized using hard-templating and evaporationinduced self-assembly(EISA)methods,respectively.The pore structures of CMK-3 and CFDU-15 as well as commercial activated carbon were characterized by means of X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and N2 adsorption–desorption.Adsorption of NO was investigated by means of thermogravimetric analysis,temperature-programmed desorption of NO+O2,and in situ diffuse reflectance Fourier transform infrared spectroscopy.The results show that the CMK-3 and C-FDU-15 materials possessed ordered and uniform structures.The coadsorption capacity of NO and O2 decreased in the sequence CMK-3(88.6 mg/g)>C-FDU-15(71.7 mg/g)>AC(25.3 mg/g).There were two main adsorption species on CMK-3 and CFDU-15:nitrite and nitrate.Nitrite is converted to nitrate easily.However,the adsorption species were more complex on AC,with nitrite being the main species.Moreover,CMK-3 and C-FDU-15 exhibit excellent regeneration efficiency compared with AC.The excellent NO adsorption performance of CMK-3 and C-FDU-15 was associated with their ordered mesoporous structures and high surface areas.The research provides more options for NO adsorption in the future.展开更多
基金Project(2018YFB0105303)supported by the Ministry of Science and Technology of ChinaProject(17DZ1200702)supported by the Shanghai Science and Technology Committee,China
文摘Fuel cell stacks as the automotive power source can be severely poisoned by a trace amount of NOx in atmosphere,which makes it necessary to provide clean air for fuel cell vehicles.In this work,activating commercial activated carbons with K2CO3 for the large enhancement of NO capture was studied.K2CO3 modified activated carbons(K2CO3 ACs)were prepared by impregnating activate carbons in K2CO3 solution under ultrasound treatment,followed by temperature programmed baking at 800 oC.The dynamic NO flow tests on K2CO3 ACs at room temperature indicated that NO adsorption capacity reached the maximum(96 mg/g)when K2CO3 loading was 19.5 wt%,which corresponded to a specific surface area of 1196.1 m2/g and total pore volume of 0.70 cm3/g.The ten-fold enhancement of NO adsorption on K2CO3 ACs compared to the unimpregnated activated carbon was mainly attributed to the formation of potassium nitrite,which was confirmed by FTIR and temperature programmed desorption measurements.Regeneration tests of NO adsorption on the optimum sample revealed that 76%of the NO adsorption capacity could be remained after the fourth cycle.
文摘s: Three kinds of Co sites,i.e. tetrahedral(Co[o]), cobalt cobalt sites and bulk Co3O4 are characterized by infrared spechoscopy of CO and NO adsothed on reduced and sueded Co/Al2O3 at room temperature.
基金supported by the National Natural Science Foundation of China (20873076 and 20873075)
文摘The activities of neutral, anionic, and cationic Au（111）, Au（100）, surface towards NO adsorption have been studied by performing and Au（310） surfaces, as well as an Au adatom on Au（111） density functional theory calculations. It was found that the activity of gold increases as the coordination number of the gold atoms decreases, and that the cationic surfaces are generally more active than the neutral and anionic surfaces. The activity of Au surfaces towards NO adsorption is attributable to the presence of low coordinated gold atoms and the concentration of positive charges on the surface. The results may enrich the understanding of NO adsorption on Au surfaces.
文摘Thee adsorption of CO and NO on copper ion-exchanged zeolite Beta was investigated using IR method.It was found that the thermalvacuum pretreatment procedure could result in the reduction of Cu2+ions in zeolite Beta.The adsorption of CO on Cu+sites in zeolite Beta closely follows Langmuir isotherm.Another Cu+species may form during the reaction between water and CO.The catalytic decomposition of NO on the zeolite was observed at room temperature,indicating that the decomposition reaction may occur between two coordinated NO ligands of the same dinitrosyhc complex.Furthermore,the appearance of two series of NO adsorption bands reveals that copper ions existing at different cation sites may have different effect on the adsorption and decomposition of NO molecules.
基金supported by the National Natural Science Foundation of China(Nos.21277008 and 20777005)the National Key Research and Development Program of China(No.2017YFC0209905)
文摘CMK-3 and C-FDU-15 samples were synthesized using hard-templating and evaporationinduced self-assembly(EISA)methods,respectively.The pore structures of CMK-3 and CFDU-15 as well as commercial activated carbon were characterized by means of X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and N2 adsorption–desorption.Adsorption of NO was investigated by means of thermogravimetric analysis,temperature-programmed desorption of NO+O2,and in situ diffuse reflectance Fourier transform infrared spectroscopy.The results show that the CMK-3 and C-FDU-15 materials possessed ordered and uniform structures.The coadsorption capacity of NO and O2 decreased in the sequence CMK-3(88.6 mg/g)>C-FDU-15(71.7 mg/g)>AC(25.3 mg/g).There were two main adsorption species on CMK-3 and CFDU-15:nitrite and nitrate.Nitrite is converted to nitrate easily.However,the adsorption species were more complex on AC,with nitrite being the main species.Moreover,CMK-3 and C-FDU-15 exhibit excellent regeneration efficiency compared with AC.The excellent NO adsorption performance of CMK-3 and C-FDU-15 was associated with their ordered mesoporous structures and high surface areas.The research provides more options for NO adsorption in the future.
