The adsorption of methanol in the acid sites of zeolites has attracted a great deal of attention because of its relevance to the industrial methanol to gasoline conversion process. In this work, the B3LYP hybrid densi...The adsorption of methanol in the acid sites of zeolites has attracted a great deal of attention because of its relevance to the industrial methanol to gasoline conversion process. In this work, the B3LYP hybrid density functional method was used to investigate the adsorption behavior of methanol on Bronsted acid sites in B, Al, Ga and Fe isomorphously substituted ZSM-5 zeolites. The optimized structures reveal a physisorbed methanol interacting with the zeolite framework through two hydrogen bonds. The order of the computed adsorption energy correlates with the acid strength of the isomorphously substituted ZSM-5: B-ZSM-5《Fe-ZSM-5<Ga-ZSM-5<Al-ZSM-5. The adsorption difference between methanol and ammonia is compared.展开更多
Fe^(3+) substituted ZSM-5 zeolite was studied using EPR and ^(27)A1,^(29)Si MAS-NMR spectroscopy.The results showed that the synthe- sized sample has the typical ZSM-5 structure with Fe^(3+) ionsincorporated in tetrah...Fe^(3+) substituted ZSM-5 zeolite was studied using EPR and ^(27)A1,^(29)Si MAS-NMR spectroscopy.The results showed that the synthe- sized sample has the typical ZSM-5 structure with Fe^(3+) ionsincorporated in tetrahedric sites in the zeolite framework and there are some para- magnetic centers in the samples.展开更多
Reaction of heterocycle substituted telluronium salts with aroma- tic aldehydes under mild conditions gave corresponding chalcones.In the presence of dibutyl telluride,2-bromomethyl-5-nitrofuran condensed easily with ...Reaction of heterocycle substituted telluronium salts with aroma- tic aldehydes under mild conditions gave corresponding chalcones.In the presence of dibutyl telluride,2-bromomethyl-5-nitrofuran condensed easily with aromatic aldehydes in THF to afford corresponding olefin derivatives as one-pot reaction.展开更多
基金This work is supported by the National Natural Science Foundation of China(No.20073057)
文摘The adsorption of methanol in the acid sites of zeolites has attracted a great deal of attention because of its relevance to the industrial methanol to gasoline conversion process. In this work, the B3LYP hybrid density functional method was used to investigate the adsorption behavior of methanol on Bronsted acid sites in B, Al, Ga and Fe isomorphously substituted ZSM-5 zeolites. The optimized structures reveal a physisorbed methanol interacting with the zeolite framework through two hydrogen bonds. The order of the computed adsorption energy correlates with the acid strength of the isomorphously substituted ZSM-5: B-ZSM-5《Fe-ZSM-5<Ga-ZSM-5<Al-ZSM-5. The adsorption difference between methanol and ammonia is compared.
文摘Fe^(3+) substituted ZSM-5 zeolite was studied using EPR and ^(27)A1,^(29)Si MAS-NMR spectroscopy.The results showed that the synthe- sized sample has the typical ZSM-5 structure with Fe^(3+) ionsincorporated in tetrahedric sites in the zeolite framework and there are some para- magnetic centers in the samples.
文摘Reaction of heterocycle substituted telluronium salts with aroma- tic aldehydes under mild conditions gave corresponding chalcones.In the presence of dibutyl telluride,2-bromomethyl-5-nitrofuran condensed easily with aromatic aldehydes in THF to afford corresponding olefin derivatives as one-pot reaction.
