With B-ZSM-5 zeolite from modified hydrothermal synthesis as precursor,Ti-ZSM-5 samples were synthesized under different gas-solid reaction temperature.The samples were characterized with TG,XRD,XRF,FT-IR,UV-Vis and s...With B-ZSM-5 zeolite from modified hydrothermal synthesis as precursor,Ti-ZSM-5 samples were synthesized under different gas-solid reaction temperature.The samples were characterized with TG,XRD,XRF,FT-IR,UV-Vis and so on.The phenol hydroxylation properties of Ti-ZSM-5 were also investigated.The results show that,the gas-solid reaction temperature affects the type and amount of titanium in Ti-ZSM-5.Ti-ZSM-5 samples from gas-solid synthesis with the gas-solid reaction temperature from 423 K to 873 K show similar properties in phenol hydroxylation.The effect of extra-framework titanium on phenol hydroxylation properties is neglectable.展开更多
The epoxidation of allyl chloride with H2O2 on Ti-ZSM-5 prepared by isomorphous substitution of HZSM-5 with TiCl4 gas was studied. The results show that Ti-ZSM-5 has a high catalytic efficiency for the epoxidation of ...The epoxidation of allyl chloride with H2O2 on Ti-ZSM-5 prepared by isomorphous substitution of HZSM-5 with TiCl4 gas was studied. The results show that Ti-ZSM-5 has a high catalytic efficiency for the epoxidation of allyl chloride. The H2O2 utilization reaches 99.50% when the allyl chloride/H2O2 molar ratio is > 1. The effect of solvent species, catalyst concentration, H2O2 and allyl chloride concentration and reaction temperature on the epoxidation was investigated simultaneously. It is found that methanol is the best solvent for the reaction. The reaction rate equation with v = k[Cat. ] [H2O2]1/2-[C3H5Cl] and the apparent activation energy with Ea = 63.462 kJ/mol are obtained according to the kinetics study.展开更多
The effect of Al3+, NH, Na+ on the Ti content in the preparation of Ti-ZSM-5 by the isomorphous substitution of ZSM-5 using gaseous TiCl4 as titanium resource has been investigated. It is surprisingly found that altho...The effect of Al3+, NH, Na+ on the Ti content in the preparation of Ti-ZSM-5 by the isomorphous substitution of ZSM-5 using gaseous TiCl4 as titanium resource has been investigated. It is surprisingly found that although the direct ratio exists between the Ti content and the content of the skeletal Al: y=0.08x2+0.57x+1.23(here y represents TiO2% and x represents Al2O3%). but the catalytic activities of Ti-ZSM-5 for the oxidation of styrene sharply rise with the decrease of TiO2%. The skeletal Al hinders the Ti incorporation into the framework of molecular sieves characterized by FT-IR technique. At the same . NH ion has no effect on the Ti incorporation. but Na+ ion does.展开更多
文摘With B-ZSM-5 zeolite from modified hydrothermal synthesis as precursor,Ti-ZSM-5 samples were synthesized under different gas-solid reaction temperature.The samples were characterized with TG,XRD,XRF,FT-IR,UV-Vis and so on.The phenol hydroxylation properties of Ti-ZSM-5 were also investigated.The results show that,the gas-solid reaction temperature affects the type and amount of titanium in Ti-ZSM-5.Ti-ZSM-5 samples from gas-solid synthesis with the gas-solid reaction temperature from 423 K to 873 K show similar properties in phenol hydroxylation.The effect of extra-framework titanium on phenol hydroxylation properties is neglectable.
文摘The epoxidation of allyl chloride with H2O2 on Ti-ZSM-5 prepared by isomorphous substitution of HZSM-5 with TiCl4 gas was studied. The results show that Ti-ZSM-5 has a high catalytic efficiency for the epoxidation of allyl chloride. The H2O2 utilization reaches 99.50% when the allyl chloride/H2O2 molar ratio is > 1. The effect of solvent species, catalyst concentration, H2O2 and allyl chloride concentration and reaction temperature on the epoxidation was investigated simultaneously. It is found that methanol is the best solvent for the reaction. The reaction rate equation with v = k[Cat. ] [H2O2]1/2-[C3H5Cl] and the apparent activation energy with Ea = 63.462 kJ/mol are obtained according to the kinetics study.
文摘The effect of Al3+, NH, Na+ on the Ti content in the preparation of Ti-ZSM-5 by the isomorphous substitution of ZSM-5 using gaseous TiCl4 as titanium resource has been investigated. It is surprisingly found that although the direct ratio exists between the Ti content and the content of the skeletal Al: y=0.08x2+0.57x+1.23(here y represents TiO2% and x represents Al2O3%). but the catalytic activities of Ti-ZSM-5 for the oxidation of styrene sharply rise with the decrease of TiO2%. The skeletal Al hinders the Ti incorporation into the framework of molecular sieves characterized by FT-IR technique. At the same . NH ion has no effect on the Ti incorporation. but Na+ ion does.
