The synthesis of pyridine from aldehydes and ammonia was performed over ZSM-5 catalyst. The catalytic activity in reaction was correlated with the acidity of the zeolite catalysts. A few of ZSM-5 (m(SiO2)/m(Al2O3)=120...The synthesis of pyridine from aldehydes and ammonia was performed over ZSM-5 catalyst. The catalytic activity in reaction was correlated with the acidity of the zeolite catalysts. A few of ZSM-5 (m(SiO2)/m(Al2O3)=120) were prepared and modified with Co2+, Fe3+. The surface acidity was determined by Py-IR technique. It was found that CoZSM-5 and FeZSM-5 have fewer Lewis acid sites than HZSM-5. The decrease of Lewis acid sites leads to decreasing the ability of NH3 adsorption, this phenomenon insures that there are adequate acid sites discovering and reacting with aldehydes. It is advantageous to the reaction. By using a CoZSM-5 catalyst, the yields of pyridine base can reach 78%. The study provides a theoretical base for preparing high activity and high selective catalyst for pyridine synthesis.展开更多
Abstract A novel polyglycidylmethacrylate （PGMA） microspheres with high adsorption capacity of Cr（VI） was prepared by cerium（IV） initiated graft polymerization of tentacle-type polymer chains with amino group on...Abstract A novel polyglycidylmethacrylate （PGMA） microspheres with high adsorption capacity of Cr（VI） was prepared by cerium（IV） initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups. The micron-sized PGMA microspheres were prepared by a dispersion polym erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups. The polymer microspheres were characterized by scanning electron microscopy （SEM） and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the polymer microspheres had an average diameter of 5 m with uniform size distribution. The free amino group content was determined to be 5.13 mmol·g^-1 for g;PGMA-NH2 microspheres by potentiometric and conductometric titration methods. The Cr（VI） adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity （500 mg-g-l）. The polymer microspheres with grafted tentacle polymer chains have potenial application in large-scale removal of Cr（VI） in aqueous solution.展开更多
文摘The synthesis of pyridine from aldehydes and ammonia was performed over ZSM-5 catalyst. The catalytic activity in reaction was correlated with the acidity of the zeolite catalysts. A few of ZSM-5 (m(SiO2)/m(Al2O3)=120) were prepared and modified with Co2+, Fe3+. The surface acidity was determined by Py-IR technique. It was found that CoZSM-5 and FeZSM-5 have fewer Lewis acid sites than HZSM-5. The decrease of Lewis acid sites leads to decreasing the ability of NH3 adsorption, this phenomenon insures that there are adequate acid sites discovering and reacting with aldehydes. It is advantageous to the reaction. By using a CoZSM-5 catalyst, the yields of pyridine base can reach 78%. The study provides a theoretical base for preparing high activity and high selective catalyst for pyridine synthesis.
基金Supported by the National Natural Science Foundation of China (21106162)the National Key Natural Science Foundation of China (21136009)+1 种基金the National High Technology Research and Development Program of China (2009CB219904)the State Key Laboratory of Chemical Engineering (SKL-ChE-11A04)
文摘Abstract A novel polyglycidylmethacrylate （PGMA） microspheres with high adsorption capacity of Cr（VI） was prepared by cerium（IV） initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups. The micron-sized PGMA microspheres were prepared by a dispersion polym erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups. The polymer microspheres were characterized by scanning electron microscopy （SEM） and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the polymer microspheres had an average diameter of 5 m with uniform size distribution. The free amino group content was determined to be 5.13 mmol·g^-1 for g;PGMA-NH2 microspheres by potentiometric and conductometric titration methods. The Cr（VI） adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity （500 mg-g-l）. The polymer microspheres with grafted tentacle polymer chains have potenial application in large-scale removal of Cr（VI） in aqueous solution.
