Storage-reduction of NOx by carbon monoxide was investigated over combined catalysts of Mn/Ba/Al2O3-Pt/Ba/Al2O3. Combination of Mn/Ba/Al2O3 and Pt/Ba/Al2O3 catalysts in different ways showed excellent NOx storage-redu...Storage-reduction of NOx by carbon monoxide was investigated over combined catalysts of Mn/Ba/Al2O3-Pt/Ba/Al2O3. Combination of Mn/Ba/Al2O3 and Pt/Ba/Al2O3 catalysts in different ways showed excellent NOx storage-reduction performance and the content of Pt could be reduced by 50%. Not only the addition of 5Mn/15Ba/Al2O3 to 1Pt/15Ba/Al2O3 could improve its storage ability, but also enhance the NOx conversion consequently. NOx conversion over the combined catalysts （the combined catalysts Ⅰ and Ⅱ） was increased under dynamic lean-rich burn conditions, the maximum NOx conversion increased from 69.4% to respectively 78.8% and 75.7% over two combined catalysts.展开更多
The new type heterogeneous combined catalyst system TiCl4-(α-diimine)nickel(Ⅱ) complexes/MgCl2-SiO2/AlR3 was prepared. Ethylene and 1-butene were copolymerized with the catalysts in slurry phase. It was found that w...The new type heterogeneous combined catalyst system TiCl4-(α-diimine)nickel(Ⅱ) complexes/MgCl2-SiO2/AlR3 was prepared. Ethylene and 1-butene were copolymerized with the catalysts in slurry phase. It was found that with combined catalyst, the copolymers with lower density and higher branched degree were obtained. 13CNMR results showed that in the obtained copolymers existed not only ethyl but also some other kinds of branches due to the fact that ethylene exhibits the behavior of oligomerization and copolymerization in-situ with combined catalysts.展开更多
Diimine)nickel {[C 6 H 5 -N = C(CH 3 ) - C(CH 3 ) = N - QH 5 ]NiBr 2 }-TiCl 4 , abbreviated as NiL-TiCl 4 combined catalyst which is supported on MgCl 2 -SiO 2 carrier has been prepared, by using alkyl aluminum (AlR 3...Diimine)nickel {[C 6 H 5 -N = C(CH 3 ) - C(CH 3 ) = N - QH 5 ]NiBr 2 }-TiCl 4 , abbreviated as NiL-TiCl 4 combined catalyst which is supported on MgCl 2 -SiO 2 carrier has been prepared, by using alkyl aluminum (AlR 3 ) as the cocatalyst in place of methylaluminoxane (MAO) to catalyze ethylene oligomerization and copolymerization in situ. The influences of procedure for supporting NiL-TiCl 4 , the molar ratio of NiL to TiCl 4 , cocatalyst type and polymerization temperature on the catalytic performance were studied. The degree of branching and the composition of the branched chain of polymers produced have been investigated by IR and 13C-NMR spectra. The results show that the combined catalyst can synthesize the branched polyethylene with various banched chains .The polymerization reaction was monitored by gas chromatography and mass spectrometry (GC-MS). The results show that this catalyst promotes the oligomerization and copolymerization in situ for ethylene.展开更多
A novel four-way combining catalysts containing double layers was applied to simultaneously remove four kinds of exhaust pollutants （NOx, CO, HC and PM） emitted from diesel engine. The four-way catalysts were charac...A novel four-way combining catalysts containing double layers was applied to simultaneously remove four kinds of exhaust pollutants （NOx, CO, HC and PM） emitted from diesel engine. The four-way catalysts were characterized using scanning electron microscope （SEM） and Ultraviolet visible diffuse reflectance spectroscopy （UV-Vis DRS）. Their catalytic performances were evaluated by temperature-programmed reaction technology. The double layer catalysts could effectively remove the four main pollutants. The highest catalytic activity was given by the two-layered catalysts of La0.6 K0.4CoO3/Al2O3 and W/HZSM-5. Under the simulated exhaust gases conditions, the peak temperature of the soot combustion was 421℃, the maximal conversion of NO to N2 was 74%, the temperature of the HC total conversion was 357℃, and the maximum conversion ratio of CO was 99%.展开更多
基金The National Natural Science Foundation of China(Grant No.20476032)the Natural Science Foundation of Guangdong Province(Grant No.06025654)are gratefully acknowledged for financial supports of this project.
文摘Storage-reduction of NOx by carbon monoxide was investigated over combined catalysts of Mn/Ba/Al2O3-Pt/Ba/Al2O3. Combination of Mn/Ba/Al2O3 and Pt/Ba/Al2O3 catalysts in different ways showed excellent NOx storage-reduction performance and the content of Pt could be reduced by 50%. Not only the addition of 5Mn/15Ba/Al2O3 to 1Pt/15Ba/Al2O3 could improve its storage ability, but also enhance the NOx conversion consequently. NOx conversion over the combined catalysts （the combined catalysts Ⅰ and Ⅱ） was increased under dynamic lean-rich burn conditions, the maximum NOx conversion increased from 69.4% to respectively 78.8% and 75.7% over two combined catalysts.
文摘The new type heterogeneous combined catalyst system TiCl4-(α-diimine)nickel(Ⅱ) complexes/MgCl2-SiO2/AlR3 was prepared. Ethylene and 1-butene were copolymerized with the catalysts in slurry phase. It was found that with combined catalyst, the copolymers with lower density and higher branched degree were obtained. 13CNMR results showed that in the obtained copolymers existed not only ethyl but also some other kinds of branches due to the fact that ethylene exhibits the behavior of oligomerization and copolymerization in-situ with combined catalysts.
基金This project was supported by the National Natural Science Foundation of China (No. 29874039) and the Foundation ofGuangdong Province (No. 031598).
文摘Diimine)nickel {[C 6 H 5 -N = C(CH 3 ) - C(CH 3 ) = N - QH 5 ]NiBr 2 }-TiCl 4 , abbreviated as NiL-TiCl 4 combined catalyst which is supported on MgCl 2 -SiO 2 carrier has been prepared, by using alkyl aluminum (AlR 3 ) as the cocatalyst in place of methylaluminoxane (MAO) to catalyze ethylene oligomerization and copolymerization in situ. The influences of procedure for supporting NiL-TiCl 4 , the molar ratio of NiL to TiCl 4 , cocatalyst type and polymerization temperature on the catalytic performance were studied. The degree of branching and the composition of the branched chain of polymers produced have been investigated by IR and 13C-NMR spectra. The results show that the combined catalyst can synthesize the branched polyethylene with various banched chains .The polymerization reaction was monitored by gas chromatography and mass spectrometry (GC-MS). The results show that this catalyst promotes the oligomerization and copolymerization in situ for ethylene.
基金supported by the Hi-Tech Research and Development Program (863) of China (No.SQ2009AA06Z313)the National Natural Science Foundation of China (No. 20803093,20833011)+1 种基金the Doctor Selected Foundation for the University of State Education Ministry of China (No. 200804251016)the Beijing Outstanding Ph.D Thesis Foundation (No. YB20091141401)
文摘A novel four-way combining catalysts containing double layers was applied to simultaneously remove four kinds of exhaust pollutants （NOx, CO, HC and PM） emitted from diesel engine. The four-way catalysts were characterized using scanning electron microscope （SEM） and Ultraviolet visible diffuse reflectance spectroscopy （UV-Vis DRS）. Their catalytic performances were evaluated by temperature-programmed reaction technology. The double layer catalysts could effectively remove the four main pollutants. The highest catalytic activity was given by the two-layered catalysts of La0.6 K0.4CoO3/Al2O3 and W/HZSM-5. Under the simulated exhaust gases conditions, the peak temperature of the soot combustion was 421℃, the maximal conversion of NO to N2 was 74%, the temperature of the HC total conversion was 357℃, and the maximum conversion ratio of CO was 99%.
