The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In t...The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In this work, we designed and synthesized a novel, solid-supported, and heterogeneous pseudo-single atom Pt catalyst with high activity and recyclability. Superparamagnetic Fe3O4-SiO2 core--shell nanoparticles （NPs） were used as the substrate. The functionalization of the SiO2 shell with silane coupling agents containing vinyl groups allows stabilizing Pt on the SiO2 surface through complexation. The as-prepared pseudosingle atom Pt displays high activity in the hydrosilylation of allyl-terminated polyether with polymethylhydrosiloxane and could be easily collected by applying a magnetic field. The Pt/vinyl/SiO2/Fe3O4 catalyst can be reused for up to four reaction cycles without appreciable decrease in activity. This work demonstrates a novel strategy for the design of pseudo-single atom noble metal catalysts for processes in high-viscosity media.展开更多
A magnetic porous carbon composite(MPC)was prepared from metal-organic frameworks(MOFs)by the onestep calcination method.The MPC was characterized by SEM,TEM,TG,DTG,Raman and XPS.The adsorption and degradation perform...A magnetic porous carbon composite(MPC)was prepared from metal-organic frameworks(MOFs)by the onestep calcination method.The MPC was characterized by SEM,TEM,TG,DTG,Raman and XPS.The adsorption and degradation performance of MPC towards four organic dyes were investigated.The maximum adsorption amount of magenta on MPC was 191.94 mg g^(-1) at 25℃.Furthermore,the MPC showed remarkable stability for it can be recycled 5 times through the facile magnetic separation without obvious loss of activity.The degradation efficiency of MPC toward four kinds of organic pollutants was nearly 100%within 36 min,which was much higher than that previously reported.展开更多
Waste plastics are serious environmental threats due to their low degradability and low recycling rate.Rapid and efficient waste plastics recycling technologies are urgently demanded for a sustainable future.Herein,we...Waste plastics are serious environmental threats due to their low degradability and low recycling rate.Rapid and efficient waste plastics recycling technologies are urgently demanded for a sustainable future.Herein,we report a rapid,closed-loop,and streamlined process to convert polyesters such as poly(ethylene terephthalate)(PET)back to its purified monomers.Using trifluoromethanesulfonic acid or metal triflates as the recyclable catalyst,polyesters such as PET can be completely depolymerized by simple carboxylic acids within 1 h.By coupling this acidolysis with a subsequent hydrogenolysis process,the consumed carboxylic acid was recovered and the closed-loop of PET depolymerization could be established.All catalysts and depolymerization agents are fully recycled while only PET and hydrogen are consumed.展开更多
We have developed an iron（III） phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excel...We have developed an iron（III） phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room‐tem‐perature conditions, short reaction time, high yields, simple work‐up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.展开更多
An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was d...An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.展开更多
An efficient reduction system of benzaldehyde with hydrogen under ambient pressure was developed using facile NiO catalyst. The non-aromatic solvents such as cyclohexane, tetrahydrofuran (THF) and n-hexane, and the ad...An efficient reduction system of benzaldehyde with hydrogen under ambient pressure was developed using facile NiO catalyst. The non-aromatic solvents such as cyclohexane, tetrahydrofuran (THF) and n-hexane, and the addi-tive with strong basicity e.g. KOH, were necessary for smooth conversion of the substrate. That the catalyst can be recov-ered and reused for nine times without loss of catalytic activity indicates that this catalyst is a recyclable one for benzal-dehyde reduction.展开更多
For the first time,we employed the halogen-free deep eutectic solvent(DES)into the Knoevenagel condensation between aromatic aldehydes and active methylene compounds at room temperature.The DESs[3Im:PTSA]and[4Im:PTSA]...For the first time,we employed the halogen-free deep eutectic solvent(DES)into the Knoevenagel condensation between aromatic aldehydes and active methylene compounds at room temperature.The DESs[3Im:PTSA]and[4Im:PTSA]were prepared by imidazole(Im)and p-tol-uenesulfonic acid(PTSA),which were experimentally screened from a series of organic acids with imidazole.a,b-Unsaturated carbonyl compounds were obtained in good to excellent yields under solvent-free conditions with fast reaction rate.These two DESs can be reused for multiple times with no loss of catalytic activity.展开更多
An efficient solvent free method for the synthesis of various 3,4-dihydropyrimidin-2（1H）-one/thiones in excellent yields using sulfonatedβ-cyclodextrine as recyclable catalyst is described.Sulfonatedβ-cyclodextrin...An efficient solvent free method for the synthesis of various 3,4-dihydropyrimidin-2（1H）-one/thiones in excellent yields using sulfonatedβ-cyclodextrine as recyclable catalyst is described.Sulfonatedβ-cyclodextrine was found to be efficient,recyclable heterogeneous catalyst and showed rate enhancements,high yields and short reaction times in this transformation.展开更多
1,8-Dioxo-octahydroxanthenes (4a-4f) and 1,8-dioxohexahydroacridines (5a-5c) were synthesized by novel, simple and eco-friendly method with higher yields in the presence of magnetically separable nano nickel-cobalt fe...1,8-Dioxo-octahydroxanthenes (4a-4f) and 1,8-dioxohexahydroacridines (5a-5c) were synthesized by novel, simple and eco-friendly method with higher yields in the presence of magnetically separable nano nickel-cobalt ferrite catalyst (Ni0.5Co0.5Fe2O4). The former, 1,8-dioxo-octahydroxanthenes have been synthesized from dimedone and different aromatic aldehydes, while the latter from this mixture are along with ammonium acetate. The main advantage of this method is that the nano catalyst can be reused up to five reaction cycles without losing the catalytic activity.展开更多
基金This work is partially supported by the National Natural Science Foundation of China （No. 21303265） and Ph.D. Programs Foundation of Ministry of Education of China （No. 20130007120012）.
文摘The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In this work, we designed and synthesized a novel, solid-supported, and heterogeneous pseudo-single atom Pt catalyst with high activity and recyclability. Superparamagnetic Fe3O4-SiO2 core--shell nanoparticles （NPs） were used as the substrate. The functionalization of the SiO2 shell with silane coupling agents containing vinyl groups allows stabilizing Pt on the SiO2 surface through complexation. The as-prepared pseudosingle atom Pt displays high activity in the hydrosilylation of allyl-terminated polyether with polymethylhydrosiloxane and could be easily collected by applying a magnetic field. The Pt/vinyl/SiO2/Fe3O4 catalyst can be reused for up to four reaction cycles without appreciable decrease in activity. This work demonstrates a novel strategy for the design of pseudo-single atom noble metal catalysts for processes in high-viscosity media.
基金supported by the National Natural Science Foundation of China(Nos.21305112,22066021,and 22174110)West Light Foundation of the Chinese Academy of Sciences(2021)+1 种基金the Special Fund Project for the Central Government to Guide Local Science and Technology Development(No.2020-2060503-17)the Industrial Support Plan of Gansu Provincial Department of Education,China(No.2021CYZC-01).
文摘A magnetic porous carbon composite(MPC)was prepared from metal-organic frameworks(MOFs)by the onestep calcination method.The MPC was characterized by SEM,TEM,TG,DTG,Raman and XPS.The adsorption and degradation performance of MPC towards four organic dyes were investigated.The maximum adsorption amount of magenta on MPC was 191.94 mg g^(-1) at 25℃.Furthermore,the MPC showed remarkable stability for it can be recycled 5 times through the facile magnetic separation without obvious loss of activity.The degradation efficiency of MPC toward four kinds of organic pollutants was nearly 100%within 36 min,which was much higher than that previously reported.
基金provided by the National Natural Science Foundation of China(Grant No.21673141)ShanghaiTech University start-up fundingsupport from the Analytical Instrumentation Center(Grant No.SPST-AIC10112914),SPST,ShanghaiTech University,for compound characterization
文摘Waste plastics are serious environmental threats due to their low degradability and low recycling rate.Rapid and efficient waste plastics recycling technologies are urgently demanded for a sustainable future.Herein,we report a rapid,closed-loop,and streamlined process to convert polyesters such as poly(ethylene terephthalate)(PET)back to its purified monomers.Using trifluoromethanesulfonic acid or metal triflates as the recyclable catalyst,polyesters such as PET can be completely depolymerized by simple carboxylic acids within 1 h.By coupling this acidolysis with a subsequent hydrogenolysis process,the consumed carboxylic acid was recovered and the closed-loop of PET depolymerization could be established.All catalysts and depolymerization agents are fully recycled while only PET and hydrogen are consumed.
基金supported by the Industrial Research Project of Shaanxi Science and Technology Department(2014K08-29)Science and Technology Plan Project of Xi’an(CXY1511(7))Scientific Research Foundation of Northwest University~~
文摘We have developed an iron（III） phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room‐tem‐perature conditions, short reaction time, high yields, simple work‐up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.
文摘An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.
基金Supported by the National Natural Science Foundation of China (Nos.20576045, 20306009 and 202225620).
文摘An efficient reduction system of benzaldehyde with hydrogen under ambient pressure was developed using facile NiO catalyst. The non-aromatic solvents such as cyclohexane, tetrahydrofuran (THF) and n-hexane, and the addi-tive with strong basicity e.g. KOH, were necessary for smooth conversion of the substrate. That the catalyst can be recov-ered and reused for nine times without loss of catalytic activity indicates that this catalyst is a recyclable one for benzal-dehyde reduction.
基金The financial support from National Natural Science Foundation of China(21576081,21776074 and 2181101120)is greatly acknowledged.
文摘For the first time,we employed the halogen-free deep eutectic solvent(DES)into the Knoevenagel condensation between aromatic aldehydes and active methylene compounds at room temperature.The DESs[3Im:PTSA]and[4Im:PTSA]were prepared by imidazole(Im)and p-tol-uenesulfonic acid(PTSA),which were experimentally screened from a series of organic acids with imidazole.a,b-Unsaturated carbonyl compounds were obtained in good to excellent yields under solvent-free conditions with fast reaction rate.These two DESs can be reused for multiple times with no loss of catalytic activity.
基金supported by Natural Science Foundation of China(21107071,51273112)Shanghai Government(10dj1400100,10PJ1408200,11YZ88,12CG52 and ssd10014)Shanghai Key Laboratory of Rare Earth Functional Materials
基金Financial support of this work from the Research Council of Mazandaran University
文摘An efficient solvent free method for the synthesis of various 3,4-dihydropyrimidin-2（1H）-one/thiones in excellent yields using sulfonatedβ-cyclodextrine as recyclable catalyst is described.Sulfonatedβ-cyclodextrine was found to be efficient,recyclable heterogeneous catalyst and showed rate enhancements,high yields and short reaction times in this transformation.
文摘1,8-Dioxo-octahydroxanthenes (4a-4f) and 1,8-dioxohexahydroacridines (5a-5c) were synthesized by novel, simple and eco-friendly method with higher yields in the presence of magnetically separable nano nickel-cobalt ferrite catalyst (Ni0.5Co0.5Fe2O4). The former, 1,8-dioxo-octahydroxanthenes have been synthesized from dimedone and different aromatic aldehydes, while the latter from this mixture are along with ammonium acetate. The main advantage of this method is that the nano catalyst can be reused up to five reaction cycles without losing the catalytic activity.
