【摘 要】
：
Composite supports Zr0.5Al0.5O1.75 modified by metal oxides,such as La2O3,ZnO,Y2O3 or BaO,were prepared by co-precipitation method,and palladium catalysts suppo
【机 构】
：
Key Laboratory of Green Chemistry & Technology
论文部分内容阅读
Composite supports Zr0.5Al0.5O1.75 modified by metal oxides,such as La2O3,ZnO,Y2O3 or BaO,were prepared by co-precipitation method,and palladium catalysts supported on the modified composite supports were prepared by impregnation method.Their properties were characterized by X-ray diffraction (XRD),NH3 temperature-programmed desorption (NH3-TPD),H2 temperature-programmed reduction (H2-TPR),N2 adsorption/desorption,and CO-chemisorption.The catalytic activity and the resistance to water poisoning of the prepared Pd catalysts were tested in a simulated exhaust gas from lean-burn natural gas vehicles with and without water vapor.The results demonstrated that the modified supports had an apparent effect on the performance of Pd catalysts,compared with the Pd catalyst supported on the unmodified ZrAl.The addition of ZnO or Y2O3 promoted the conversion of CH4.In the absence of water vapor,Pd/ZnZrAl exhibited the best activity for CH4 conversion with the light-off temperature (T50) of 275 ℃ and the complete conversion temperature (T90) of 314 ℃,respectively.However,in the presence of water vapor,Pd/YZrAl was the best one over which the light-off temperature (T50) of methane was 339 ℃ and the complete conversion temperature (T90) was 371 ℃.These results indicated that Pd catalyst supported on the modified composite ZrAl support showed excellent catalytic activity at low temperature and high resistance to H2O poisoning for the exhaust purification of lean-burn natural gas vehicles.
其他文献
To find new extradiol dioxygenases(EDOs,EC 1.13.11.2),a metagenomics library was constructed from polychlorinated biphenyl-contaminated soil and was screened fo
A series of 5-substitued-3-(5-(4-(furan-2-yl)-6-methyl-2-oxo/thioxo-1,2,3,4-tetrahydropyrimidin-5-yl)-1,3,4-thiadiazol-2-ylimino)indolin-2-one derivatives were
Mixed iron-cobalt oxide (Co/Fe molar ratio=1/5) are prepared using a simple co-precipitation procedure and studied for the catalytic oxidation of carbon monoxid
A new series of N-arylquinoline derivatives 5a-x bearing 2-morpholinoquinoline moiety has been synthesized by one pot base catalyzed cyclocondensation reaction
Chiral organic-inorganic hybrid silicas can be prepared via the self-assemblies of chiral surfactants and gelators as templates.However,the relationship between
Mesoporous TiO2 nanofibers have been synthesized by a new method that combines sol-gel chemistry and electrospinning technique.The obtained mesoporous TiO2 nano
A simple and fast route for the synthesis of metal-organic framework(MOF) particles was presented.Cu3(BTC)2(HKUST-1,BTC=1,3,5-benzenetricarboxylate),one of the
We present new charge-coupled device (CCD) photometry for the triple star EF Draconis,obtained in 2009 and 2011.Using the updated Wilson-Devinney program,the ph
2-(Sulfooxy)propane-1,2,3-tricarboxylic acid (supported on silica gel) has been introduced as novel and green catalyst for the formylation of alcohols and amine
Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane der