We substituted several environmentally friendly catalysts which included HY and H- β zeolites, various cation-exchanged β zeolites, and solid-supported ferric chloride for conventional catalysts for the synth...We substituted several environmentally friendly catalysts which included HY and H- β zeolites, various cation-exchanged β zeolites, and solid-supported ferric chloride for conventional catalysts for the synthesis of 3-(1-cyclohexenyl)-2-butanone from the reaction of ethylidenecyclohexane with acetic anhydride at room temperature. HY zeolite was found to be the most effective for this reaction, and gave the acylated product in a 72% yield under the conditions of n (ethylidenecyclohexane)/ n (acetic anhydride)/ m (HY zeolite)=1 mmol/10 mmol/0 100 g, reaction temperature 25 ℃ and reaction time 2 h. The used HY zeolite can be recovered, regenerated and gave almost the same yield as the fresh one. The lifetime of the HY zeolite is over 80 h. The effect of different factors on the reaction has also been investigated.展开更多
The utilization of chelation reaction between metals and tannins is a common tanning method in leather chemistry.Herein,a novel combination tanning mechanism inspired environmentally benign catalyst(CMBT-Fe^(0))was sy...The utilization of chelation reaction between metals and tannins is a common tanning method in leather chemistry.Herein,a novel combination tanning mechanism inspired environmentally benign catalyst(CMBT-Fe^(0))was synthesized by immobilizing Fe nanoparticles onto bayberry tannin(BT)grafted chitosan microfibers(CM).The obtained catalyst featured a well-defined microfibrous structure,on which Fe^(0)nanoparticles were highly dispersed to exhibit exceptional catalytic activity for the degradation of tetracycline(TC).The catalytic activity of CMBT-Fe^(0)was 1.72 times higher than that of the commercial Fe^(0)nanoparticles without immobilization,with 95.03%of TC degraded within 90.0 min.The CMBT-Fe^(0)catalysts were recycled 6 times,with the removal rate of TC maintained at 82.56%.Furthermore,a possible mechanism responsible for the catalytic removal of TC was provided by analyzing the catalytic degradation products via liquid chromatography-mass spectrometry.Therefore,our investigation successfully developed efficient catalysts to address the concerned environmental issue of antibiotic pollution.展开更多
Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p-aminophenol in the environmentally benign pressurized CO2/H2O system.Among the bimetallic cataly...Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p-aminophenol in the environmentally benign pressurized CO2/H2O system.Among the bimetallic catalysts prepared,Pt-Pb/SiO2 is the best and nitrobenzene could be converted to paminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at110 ℃ under 5 MPa CO2 and 0.2 MPa H2.展开更多
基金Supported by the National Natural Science Foundation of China( No.2 0 1730 14 )
文摘We substituted several environmentally friendly catalysts which included HY and H- β zeolites, various cation-exchanged β zeolites, and solid-supported ferric chloride for conventional catalysts for the synthesis of 3-(1-cyclohexenyl)-2-butanone from the reaction of ethylidenecyclohexane with acetic anhydride at room temperature. HY zeolite was found to be the most effective for this reaction, and gave the acylated product in a 72% yield under the conditions of n (ethylidenecyclohexane)/ n (acetic anhydride)/ m (HY zeolite)=1 mmol/10 mmol/0 100 g, reaction temperature 25 ℃ and reaction time 2 h. The used HY zeolite can be recovered, regenerated and gave almost the same yield as the fresh one. The lifetime of the HY zeolite is over 80 h. The effect of different factors on the reaction has also been investigated.
基金supported by National Key R&D Program of China(2021YFC2103800)the Technical Development Project of Sichuan University(No.22H0798)Fundamental Research Funds for the Central Universities.
文摘The utilization of chelation reaction between metals and tannins is a common tanning method in leather chemistry.Herein,a novel combination tanning mechanism inspired environmentally benign catalyst(CMBT-Fe^(0))was synthesized by immobilizing Fe nanoparticles onto bayberry tannin(BT)grafted chitosan microfibers(CM).The obtained catalyst featured a well-defined microfibrous structure,on which Fe^(0)nanoparticles were highly dispersed to exhibit exceptional catalytic activity for the degradation of tetracycline(TC).The catalytic activity of CMBT-Fe^(0)was 1.72 times higher than that of the commercial Fe^(0)nanoparticles without immobilization,with 95.03%of TC degraded within 90.0 min.The CMBT-Fe^(0)catalysts were recycled 6 times,with the removal rate of TC maintained at 82.56%.Furthermore,a possible mechanism responsible for the catalytic removal of TC was provided by analyzing the catalytic degradation products via liquid chromatography-mass spectrometry.Therefore,our investigation successfully developed efficient catalysts to address the concerned environmental issue of antibiotic pollution.
文摘Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p-aminophenol in the environmentally benign pressurized CO2/H2O system.Among the bimetallic catalysts prepared,Pt-Pb/SiO2 is the best and nitrobenzene could be converted to paminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at110 ℃ under 5 MPa CO2 and 0.2 MPa H2.
