The synthesis of 2, 4-diisopropyl-5,5-dimethy1- 1.3-dioxane through the acetalization of isobutyraldehyde with 2, 2, 4-trimethy1-1,3-pentanediol （TMPD） catalyzed by the novel carbon based acid was first carried out....The synthesis of 2, 4-diisopropyl-5,5-dimethy1- 1.3-dioxane through the acetalization of isobutyraldehyde with 2, 2, 4-trimethy1-1,3-pentanediol （TMPD） catalyzed by the novel carbon based acid was first carried out. High conversion （≥98%） and specific selectivity were obtained using the novel carbon based acid, which kept high activity after it was reused 5 times. Moreover. the catalyst could be used to catalyze the acetalization and ketalization of different aldehydes and ketones with superior yield. The yield of several products was over 90%. The novel heterogeneous catalyst has the distinct advantages of high activity, strikingly simple workup procedure, non-pollution, and reusability, which will contribute to the success of the green process greatly.展开更多
[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separa...[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.展开更多
The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated throug...The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated through the acetalization. The results showed that the novel solid acid was very efficient for the reactions with the high yields. The high acidity, high stability and reusability were the key feature of the novel solid acid. Moreover, the sulfonic and carbonyl acid groups could cooperate during the catalytic process, which improved its catalytic activities. The catalyst shows recyclability, and hold great potential for replacement of homogeneous catalysts.展开更多
A new complex (1) was prepared by mixing pyridinium polystyrylsulfonate resin and aqueous fluoboric acid, followed by being dehydrated. 1 can be used as an acidic catalyst for the acetalization of benzaldehyde with n-...A new complex (1) was prepared by mixing pyridinium polystyrylsulfonate resin and aqueous fluoboric acid, followed by being dehydrated. 1 can be used as an acidic catalyst for the acetalization of benzaldehyde with n-butanol with a highly catalytic activity. The characterization and reusability of 1 are discussed.展开更多
Acetalizatioin on the blend fibers of poly(vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square e...Acetalizatioin on the blend fibers of poly(vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared (FTIR) spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.展开更多
A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H3P...A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H3PW12O40/MCM-48 was studied with butyraldehyde and glycol as reactants. H3PW12O40/MCM-48 was an excellent catalyst for the synthesizing butyraldehyde glycol acetal and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n（butyraldehyde）： n（glycol）, catalyst dosage, cyclohexane（water-stripped reagent） and reaction time on yields of the product were investigated. The optimum conditions had been found, that was, molar ratio of butyraldehyde to glycol was 1： 1.6, mass ratio of catalyst used to the reactants was 0.25% and reaction time was 75 min. Under these conditions, the yield of butyraldehyde glycol acetal can reach 79.74%.展开更多
The reaction of 2-formylpyrrole acetals with sodium alkoxide in alcohols at reflux temperature smoothly proceeded to generate corresponding transacetalization products in nearly quantitative yields.A plausible mechani...The reaction of 2-formylpyrrole acetals with sodium alkoxide in alcohols at reflux temperature smoothly proceeded to generate corresponding transacetalization products in nearly quantitative yields.A plausible mechanism involving the formation of a highly reactive intermediate azafulvene species was proposed to explain the observed transformation.展开更多
The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with...The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with highfraxnework Si/A1 ratio was proven to be suitable cataipst for the acetabotion ofunsaturated carbonyl compounds, during which the C =C double bond was notperturbed展开更多
Abstract Heterogeneous catalysts with convenient recyclability and reusability are vitally important to reduce the cost of catalysts as well as to avoid complex separation and recovery operations. In this regard, magn...Abstract Heterogeneous catalysts with convenient recyclability and reusability are vitally important to reduce the cost of catalysts as well as to avoid complex separation and recovery operations. In this regard, magnetic MIL-100 （Fe）@SiO2@Fe3O4 microspheres with a novel core-shell structure were fabricated by the in-situ self-assembly of a metal-organic MIL- 100（Fe） framework around pre-synthesized magnetic SiO2@Fe3O4 particles under relatively mild and environmentally benign conditions. The catalytic activity of the MIL-100（Fe）@SiO2@Fe3O4 catalyst was tested for the liquid-phase acetalization of benzaldehyde and glycol. The MIL-100（Fe）@SiO2@Fe3O4 catalyst has a significant amount of accessible Lewis acid sites and therefore exhibited good acetalization catalytic activity. Moreover, due to its superparamagnetism properties, the heterogeneous MIL-100（Fe）@SiO2@Fe3O4 catalyst can be easily isolated from the reaction system within a few seconds by simply using an external magnet. The catalyst could then be reused at least eight times without significant loss in catalytic efficiency.展开更多
Acetalization of glycol with carbonyl compounds was carded out catalyzed by cupric p-toluenesulfonate. These carbonyl compounds included cyclohexanone, propionoaldehyde, n-butyraldehyde, /so-butyraldehyde, n-valeralde...Acetalization of glycol with carbonyl compounds was carded out catalyzed by cupric p-toluenesulfonate. These carbonyl compounds included cyclohexanone, propionoaldehyde, n-butyraldehyde, /so-butyraldehyde, n-valeraldehyde, benzaldehyde and butanone. Satisfactory results were obtained： the conversions of these carbonyl compounds were more than 90%, the selectivities were higher than 99.1%, only 0.1% mole ratio of catalyst to substrate and 90 min were sufficient in most cases. The catalyst and products were separated easily by phase separation.展开更多
Hierarchical core/shell Zeolite Socony Mobil-five(ZSM-5)zeolite was hydrothermally postsythesized in the solution of NaOH and diammonium surfactant via a dissolution-reassembly strategy.The silica and alumina species ...Hierarchical core/shell Zeolite Socony Mobil-five(ZSM-5)zeolite was hydrothermally postsythesized in the solution of NaOH and diammonium surfactant via a dissolution-reassembly strategy.The silica and alumina species were firstly dissolved partially from the bulky ZSM-5 crystals and then were reassembled into the MFI-type nanosheets with the structure-directing effect of diammonium surfactant,attaching to the out-surface of ZSM-5 core crystals.The mesopores thus were generated in both the core and shell part,giving rise to a micropore/mesopore composite material.The micropore volume and the acidity of the resultant hybrid were well-preserved during this recrystallization process.Possessing the multiple mesopores and enlarged external surface area,the core/shell ZSM-5 zeolite exhibited higher activity in the ketalation and acetalization reactions involving bulky molecules in comparison to the pristine ZSM-5.展开更多
This paper reports a practical and green method for the acetalization of carbonyl compounds as pentaerythritol diacetals and diketals derivatives using cellulose sulfuric acid as a biodegradable and reusable solid aci...This paper reports a practical and green method for the acetalization of carbonyl compounds as pentaerythritol diacetals and diketals derivatives using cellulose sulfuric acid as a biodegradable and reusable solid acid catalyst under thermal solvent-free conditions.展开更多
O,O＇Diethyl acetals were prepared in high yields under mild conditions via the reaction of triethyl orthoformate with aldehydes and ketones in absolute ethanol in the presence of as low as 0.1 tool% of Yb（OTf）3. Us...O,O＇Diethyl acetals were prepared in high yields under mild conditions via the reaction of triethyl orthoformate with aldehydes and ketones in absolute ethanol in the presence of as low as 0.1 tool% of Yb（OTf）3. Using the same catalyst in THF-H2O, these O,O＇-diethyl acetals could be converted to the corresponding carbonyl compounds efficiently. This new protection-deprotection protocol presents the advantages of ease of execution, high efficiency and good chemoselectivity.展开更多
In this work,we have reported the synthesis of a series of heterogeneous catalysts,viz.,[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe,[HMIm]_(3)[PMo_(12)O_(40)]@MOF-Fe,and[HMIm]_(4)[SiW_(12)O_(40)]@MOFFe,by a simple impregnation m...In this work,we have reported the synthesis of a series of heterogeneous catalysts,viz.,[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe,[HMIm]_(3)[PMo_(12)O_(40)]@MOF-Fe,and[HMIm]_(4)[SiW_(12)O_(40)]@MOFFe,by a simple impregnation method.The catalysts were characterized by several techniques,such as FTIR,EDX,XRD,SEM,elemental mapping,and TGA.Among these materials,[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe had more acidic sites(confirmed by potentiometric titration)and high stability around 598℃(confirmed by TGA).The catalytic prospect of the materials was examined through selective acetalization of glycerol to solketal as a fuel additive under solvent-free and room-temperature conditions.[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe exhibited the highest catalytic activity among the three catalysts in terms of glycerol conversion(100%),solketal selectivity(100%),and solketal yield(100%).A recyclability study of[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe showed that the material could be reused for up to 7 cycles with insignificant loss in its catalytic performance.展开更多
Acetalization represents an appealing approach for the valorization of biobased platform molecules into valuable chemicals and fuels.Typically,it serves as both a synthesis tool for renewable cyclic acetals and a prot...Acetalization represents an appealing approach for the valorization of biobased platform molecules into valuable chemicals and fuels.Typically,it serves as both a synthesis tool for renewable cyclic acetals and a protection strategy to improve selectivity in biomass conversion.This contribution provides an overview on the application of the acetalization strategy in biomass valorization including synthesis of cyclic acetal fuel additives from the acetalization of biobased furanic compounds with biogenic ethylene glycol/glycerol and acetalization as a protection approach to improve product selectivity in biomass valorization.The latest progresses in the development of catalytic systems for the acetalization of biobased furanic compounds and biogenic ethylene glycol/glycerol are systematically summarized and discussed,with an emphasis on the reaction pathway,relationship between catalyst structures and their performance,and relevant catalytic mechanism.Moreover,the application of the acetalization strategy for protecting carbonyl groups/diol structure functionalities to improve the target products'selectivity in lignin depolymerization,5-hydroxymethylfurfural oxidation,sorbitol dehydration,and xylose hydrogenation is also highlighted.Eventually,the prospects and challenges in the synthesis of cyclic acetal fuel additives as well as applying acetalization as a protection strategy in biomass valorization are outlined.展开更多
Skin injury repair is a complicated process that involves wound healing.Effective wound dressings play a crucial role in enhancing this process by providing multiple functions,such as wettability,antibacterial activit...Skin injury repair is a complicated process that involves wound healing.Effective wound dressings play a crucial role in enhancing this process by providing multiple functions,such as wettability,antibacterial activity,and drug release.In this study,Calophyllum inophyllum oil(CIO)is incorporated into polyethylene oxide-polyvinyl acetate(PEO-PVAc)nanofibers using an electrospinning technique.The successful incorporation is verified by Fourier-transform infrared spectroscopy,while the morphology is observed by scanning electron microscopy.The fabricated nanofibers are beadless and have fiber diameter distributions of 333–472 nm.The addition of CIO significantly improves the wettability of the nanofibers,as indicated by a decrease in water contact angle,which is crucial for accelerating the healing process.Additionally,the CIO exhibits potent antibacterial activity against both Gram-positive(Escherichia coli)and Gram-negative(Staphylococcus aureus)bacteria,with expanding inhibition zones as the CIO concentration is increased.These findings highlight the great potential of PEO-PVAc/CIO nanofibers for advanced wound healing applications.展开更多
Efficiency of C-C bond coupling in highly inert CO_(2)is relatively low,which severely limits its efficient conversion to acetate.Here,we successfully developed a highly stable NF@CoMn_(2)O_(4)@Cu_(2)O-Ag bimetallic a...Efficiency of C-C bond coupling in highly inert CO_(2)is relatively low,which severely limits its efficient conversion to acetate.Here,we successfully developed a highly stable NF@CoMn_(2)O_(4)@Cu_(2)O-Ag bimetallic active site catalyst by anchoring Ag on the Cu_(2)O surface.In this catalyst,the Co^(3+)/Mn^(3+)-Mn^(4+)removes excess electrons from the Cu+sites via strong electronic interactions,preventing the reduction of Cu_(2)O to metallic Cu^(0),which ensures the NF@CoMn_(2)O_(4)@Cu_(2)O-Ag exhibits a high resistance to deactivation.The Cu+active sites of NF@CoMn_(2)O_(4)@Cu_(2)O-Ag efficiently electroreduce CO_(2)to the*COatop intermediate,while the Ag active sites efficiently electroreduce CO_(2)to the^(*)CO_(bridge)intermediate.The proximity of Cu+/Ag bimetallic sites shortens the distance for C-C bond coupling between the*COatop and^(*)CO_(bridge)intermediates,facilitating the efficient electrocatalytic coupling of CO_(2)to synthesize acetate.DFT analysis indicates that theΔG required for C-C bond coupling on the short-distance Cu+/Ag bimetallic sites of NF@CoMn_(2)O_(4)@Cu_(2)O-Ag is significantly lower than that of NF@CoMn_(2)O_(4)@Cu_(2)O,enabling a high Faradaic efficiency of 64.97%for acetate production at-0.3 V vs.RHE.This study provides an effective strategy for the rational design of synergistic catalysis between heterometallic catalytic sites to efficiently achieve C-C coupling for the synthesis of C2+products.展开更多
In order to address the evolving emission characteristics of oxygenated volatile organic compounds(OVOCs),it is essential to develop adsorbent materials specifically designed for the efficient adsorption of OVOCs with...In order to address the evolving emission characteristics of oxygenated volatile organic compounds(OVOCs),it is essential to develop adsorbent materials specifically designed for the efficient adsorption of OVOCs with large kinetic diameters.In this study,we used co-pyrolysis to prepare a series of graded porous carbon materials with well-developed micropores by adjusting the doping ratios of root nodules and pretreated cellulose.The material with root nodule to cellulose mass ratio of 1:1(TCC-RN-1)exhibited the highest saturated adsorption capacity for butyl acetate(834 mg/g).This can be attributed to enhanced pore size distribution from nodule doping,which facilitates the development of a micropore-graded structure.Additionally,the nodules acted as auxiliary activating agents that enhanced the KOH micropore regulation effect during the activation stage,resulting in the highest micropore volume(0.863 cm^(3)/g).The doping of root nodules facilitated the formation of additional defects on the surface of the porous carbon material,leading to a more disordered arrangement that improved pollutant adsorption.Furthermore,TCC-RN-1 demonstrated good thermal stability in an air atmosphere,main-taining a butyl acetate adsorption capacity exceeding 95%after five adsorption-desorption cycles.This indicates its favorable potential for industrial applications.展开更多
Photothermal synergistic catalytic systems for treating volatile organic compounds(VOCs)have attracted signif-icant attention due to their energy efficiency and potential to reduce carbon emissions.However,the mechani...Photothermal synergistic catalytic systems for treating volatile organic compounds(VOCs)have attracted signif-icant attention due to their energy efficiency and potential to reduce carbon emissions.However,the mechanism underlying the synergistic reaction remains a critical issue.This study introduces a photothermal synergistic system for the removal of ethyl acetate(EA)by synthesizing Cu-doped OMS-2(denoted as Cu-OMS-2).Under ultraviolet-visible(UV–Vis)irradiation in a flow system,the Cu-OMS-2 catalyst exhibited significantly enhanced performance in the EA degradation process,nearly doubling the effectiveness of pure OMS-2,and increasing carbon dioxide yield by 20%.This exceptional performance is attributed to the synergistic effect of increased oxygen vacancies(OV)at OMS-2 active sites and Cu doping,as confirmed by H2-TPR,O_(2)-TPD,and CO consump-tion measurements.This study clarifies the catalytic mechanism of light-assisted thermocatalysis and offers a novel strategy for designing photothermal catalysts with homogeneous Cu-doped nanorods for VOC removal.展开更多
As the core of cathode materials,sensitive metals play important roles in the optimization of acetate production from carbon dioxide(CO_(2))in microbial electrochemical system(MES).In this work,iron(Fe),copper(Cu),and...As the core of cathode materials,sensitive metals play important roles in the optimization of acetate production from carbon dioxide(CO_(2))in microbial electrochemical system(MES).In this work,iron(Fe),copper(Cu),and nickel(Ni)as sensitive metal cathode materials were evaluated for CO_(2) conversion in MES.The MES with Feelectrode as a promising electrode material demonstrated a superior CO_(2) reduction performance with a maximum acetate accumulation of 417.9±39.2 mg/L,which was 1.5 and 1.7 folds higher than that in the Ni-electrode and Cu-electrode groups,respectively.Furthermore,an outstanding electron recovery efficiency of 67.7%was shown in the Fe-electrode group.The electron transfer between electrode-suspended sludge was systematically cross-evaluated by the electrochemical behavior and extracellular polymeric substances.The Fe-electrode group had the highest electron transfer rate with 0.194 s-1(k_(app)),which was 17.6 and 21.5 times higher than that of the Cu-and Ni-electrode groups,respectively.Fe-electrode was beneficial for reducing electrochemical impedance between the electrode and suspended sludge.Additionally,redox substances in extracellular polymeric substances of the Fe-electrode group were increased,implying more favorable electron transport dynamics.Simultaneously,enrichments of functional bacteria Acetoanerobium and increased key enzymes involved in the carbonyl pathway of the Fe-electrode group were observed,which also promoted CO_(2) conversion in MES.This study provides a perspective on evaluating the promising sensitive metal electrode material for the process of CO_(2) valorization in MES and offers a reference for the subsequent electrode modification.展开更多
基金the National Key Project ofScientific and Technical SupportingPrograms Funded by the Ministry of Science & Technology of China (No.2006BAE03B06)the Shanghai International Cooperation of Science and Technology Project (No.06SR07101).
文摘The synthesis of 2, 4-diisopropyl-5,5-dimethy1- 1.3-dioxane through the acetalization of isobutyraldehyde with 2, 2, 4-trimethy1-1,3-pentanediol （TMPD） catalyzed by the novel carbon based acid was first carried out. High conversion （≥98%） and specific selectivity were obtained using the novel carbon based acid, which kept high activity after it was reused 5 times. Moreover. the catalyst could be used to catalyze the acetalization and ketalization of different aldehydes and ketones with superior yield. The yield of several products was over 90%. The novel heterogeneous catalyst has the distinct advantages of high activity, strikingly simple workup procedure, non-pollution, and reusability, which will contribute to the success of the green process greatly.
基金support from Nanjing University of Science and Technology
文摘[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.
基金Supported by the Chinese National General Administration of Quality Supervision,Inspection and Quarantine(2012IK048,2011IK041)the National Natural Science Foundation of China(21103111)
文摘The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated through the acetalization. The results showed that the novel solid acid was very efficient for the reactions with the high yields. The high acidity, high stability and reusability were the key feature of the novel solid acid. Moreover, the sulfonic and carbonyl acid groups could cooperate during the catalytic process, which improved its catalytic activities. The catalyst shows recyclability, and hold great potential for replacement of homogeneous catalysts.
基金Supported by the National Natural Science Foundation of China Natural Science Founclation of Tianjin
文摘A new complex (1) was prepared by mixing pyridinium polystyrylsulfonate resin and aqueous fluoboric acid, followed by being dehydrated. 1 can be used as an acidic catalyst for the acetalization of benzaldehyde with n-butanol with a highly catalytic activity. The characterization and reusability of 1 are discussed.
文摘Acetalizatioin on the blend fibers of poly(vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared (FTIR) spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.
基金This work was financially supported by the Natural Science Foundation of Hubei Province, China （No. 2005ABA053）.
文摘A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H3PW12O40/MCM-48 was studied with butyraldehyde and glycol as reactants. H3PW12O40/MCM-48 was an excellent catalyst for the synthesizing butyraldehyde glycol acetal and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n（butyraldehyde）： n（glycol）, catalyst dosage, cyclohexane（water-stripped reagent） and reaction time on yields of the product were investigated. The optimum conditions had been found, that was, molar ratio of butyraldehyde to glycol was 1： 1.6, mass ratio of catalyst used to the reactants was 0.25% and reaction time was 75 min. Under these conditions, the yield of butyraldehyde glycol acetal can reach 79.74%.
基金The Ministry of Education of The People's Republic of ChinaDepartment of education of Jiangxi ProvinceJiangxi Provincial Natural Science Foundation for financial support
文摘The reaction of 2-formylpyrrole acetals with sodium alkoxide in alcohols at reflux temperature smoothly proceeded to generate corresponding transacetalization products in nearly quantitative yields.A plausible mechanism involving the formation of a highly reactive intermediate azafulvene species was proposed to explain the observed transformation.
文摘The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with highfraxnework Si/A1 ratio was proven to be suitable cataipst for the acetabotion ofunsaturated carbonyl compounds, during which the C =C double bond was notperturbed
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 21576243） and the Public Project of Zhejiang Province of China （2016C37057）.
文摘Abstract Heterogeneous catalysts with convenient recyclability and reusability are vitally important to reduce the cost of catalysts as well as to avoid complex separation and recovery operations. In this regard, magnetic MIL-100 （Fe）@SiO2@Fe3O4 microspheres with a novel core-shell structure were fabricated by the in-situ self-assembly of a metal-organic MIL- 100（Fe） framework around pre-synthesized magnetic SiO2@Fe3O4 particles under relatively mild and environmentally benign conditions. The catalytic activity of the MIL-100（Fe）@SiO2@Fe3O4 catalyst was tested for the liquid-phase acetalization of benzaldehyde and glycol. The MIL-100（Fe）@SiO2@Fe3O4 catalyst has a significant amount of accessible Lewis acid sites and therefore exhibited good acetalization catalytic activity. Moreover, due to its superparamagnetism properties, the heterogeneous MIL-100（Fe）@SiO2@Fe3O4 catalyst can be easily isolated from the reaction system within a few seconds by simply using an external magnet. The catalyst could then be reused at least eight times without significant loss in catalytic efficiency.
基金Project supported by the National Natural Science Foundation of China （No. G2000048）.
文摘Acetalization of glycol with carbonyl compounds was carded out catalyzed by cupric p-toluenesulfonate. These carbonyl compounds included cyclohexanone, propionoaldehyde, n-butyraldehyde, /so-butyraldehyde, n-valeraldehyde, benzaldehyde and butanone. Satisfactory results were obtained： the conversions of these carbonyl compounds were more than 90%, the selectivities were higher than 99.1%, only 0.1% mole ratio of catalyst to substrate and 90 min were sufficient in most cases. The catalyst and products were separated easily by phase separation.
基金the financial support from Ministry of Science and Technology of China(Grant No.2016YFA0202804)the National Natural Science Foundation of China(Grant Nos.21872052,21533002,21571128 and 21603075).
文摘Hierarchical core/shell Zeolite Socony Mobil-five(ZSM-5)zeolite was hydrothermally postsythesized in the solution of NaOH and diammonium surfactant via a dissolution-reassembly strategy.The silica and alumina species were firstly dissolved partially from the bulky ZSM-5 crystals and then were reassembled into the MFI-type nanosheets with the structure-directing effect of diammonium surfactant,attaching to the out-surface of ZSM-5 core crystals.The mesopores thus were generated in both the core and shell part,giving rise to a micropore/mesopore composite material.The micropore volume and the acidity of the resultant hybrid were well-preserved during this recrystallization process.Possessing the multiple mesopores and enlarged external surface area,the core/shell ZSM-5 zeolite exhibited higher activity in the ketalation and acetalization reactions involving bulky molecules in comparison to the pristine ZSM-5.
文摘This paper reports a practical and green method for the acetalization of carbonyl compounds as pentaerythritol diacetals and diketals derivatives using cellulose sulfuric acid as a biodegradable and reusable solid acid catalyst under thermal solvent-free conditions.
基金Project supported by the National Natural Science Foundation of China （Nos. 20425205, 20321202） and the Shanghai Municipal Commission of Science and Technology （Nos. 04DZ 14901, 06QH 14016）.
文摘O,O＇Diethyl acetals were prepared in high yields under mild conditions via the reaction of triethyl orthoformate with aldehydes and ketones in absolute ethanol in the presence of as low as 0.1 tool% of Yb（OTf）3. Using the same catalyst in THF-H2O, these O,O＇-diethyl acetals could be converted to the corresponding carbonyl compounds efficiently. This new protection-deprotection protocol presents the advantages of ease of execution, high efficiency and good chemoselectivity.
文摘In this work,we have reported the synthesis of a series of heterogeneous catalysts,viz.,[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe,[HMIm]_(3)[PMo_(12)O_(40)]@MOF-Fe,and[HMIm]_(4)[SiW_(12)O_(40)]@MOFFe,by a simple impregnation method.The catalysts were characterized by several techniques,such as FTIR,EDX,XRD,SEM,elemental mapping,and TGA.Among these materials,[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe had more acidic sites(confirmed by potentiometric titration)and high stability around 598℃(confirmed by TGA).The catalytic prospect of the materials was examined through selective acetalization of glycerol to solketal as a fuel additive under solvent-free and room-temperature conditions.[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe exhibited the highest catalytic activity among the three catalysts in terms of glycerol conversion(100%),solketal selectivity(100%),and solketal yield(100%).A recyclability study of[HMIm]_(3)[PW_(12)O_(40)]@MOF-Fe showed that the material could be reused for up to 7 cycles with insignificant loss in its catalytic performance.
基金The authors gratefully acknowledge financial support from National Key R&D Program of China(2019YFC1905300)National Natural Science Foundation of China(No.22268019)Hunan Provincial Natural Science Foundation of China(No.2021JJ40436)。
文摘Acetalization represents an appealing approach for the valorization of biobased platform molecules into valuable chemicals and fuels.Typically,it serves as both a synthesis tool for renewable cyclic acetals and a protection strategy to improve selectivity in biomass conversion.This contribution provides an overview on the application of the acetalization strategy in biomass valorization including synthesis of cyclic acetal fuel additives from the acetalization of biobased furanic compounds with biogenic ethylene glycol/glycerol and acetalization as a protection approach to improve product selectivity in biomass valorization.The latest progresses in the development of catalytic systems for the acetalization of biobased furanic compounds and biogenic ethylene glycol/glycerol are systematically summarized and discussed,with an emphasis on the reaction pathway,relationship between catalyst structures and their performance,and relevant catalytic mechanism.Moreover,the application of the acetalization strategy for protecting carbonyl groups/diol structure functionalities to improve the target products'selectivity in lignin depolymerization,5-hydroxymethylfurfural oxidation,sorbitol dehydration,and xylose hydrogenation is also highlighted.Eventually,the prospects and challenges in the synthesis of cyclic acetal fuel additives as well as applying acetalization as a protection strategy in biomass valorization are outlined.
基金funded by Rekognisi Tugas Akhir(RTA)program(Contract No.5286/UN1.P1/PT.01.03/2024)supported by Universitas Gadjah Mada,Indonesia.
文摘Skin injury repair is a complicated process that involves wound healing.Effective wound dressings play a crucial role in enhancing this process by providing multiple functions,such as wettability,antibacterial activity,and drug release.In this study,Calophyllum inophyllum oil(CIO)is incorporated into polyethylene oxide-polyvinyl acetate(PEO-PVAc)nanofibers using an electrospinning technique.The successful incorporation is verified by Fourier-transform infrared spectroscopy,while the morphology is observed by scanning electron microscopy.The fabricated nanofibers are beadless and have fiber diameter distributions of 333–472 nm.The addition of CIO significantly improves the wettability of the nanofibers,as indicated by a decrease in water contact angle,which is crucial for accelerating the healing process.Additionally,the CIO exhibits potent antibacterial activity against both Gram-positive(Escherichia coli)and Gram-negative(Staphylococcus aureus)bacteria,with expanding inhibition zones as the CIO concentration is increased.These findings highlight the great potential of PEO-PVAc/CIO nanofibers for advanced wound healing applications.
文摘Efficiency of C-C bond coupling in highly inert CO_(2)is relatively low,which severely limits its efficient conversion to acetate.Here,we successfully developed a highly stable NF@CoMn_(2)O_(4)@Cu_(2)O-Ag bimetallic active site catalyst by anchoring Ag on the Cu_(2)O surface.In this catalyst,the Co^(3+)/Mn^(3+)-Mn^(4+)removes excess electrons from the Cu+sites via strong electronic interactions,preventing the reduction of Cu_(2)O to metallic Cu^(0),which ensures the NF@CoMn_(2)O_(4)@Cu_(2)O-Ag exhibits a high resistance to deactivation.The Cu+active sites of NF@CoMn_(2)O_(4)@Cu_(2)O-Ag efficiently electroreduce CO_(2)to the*COatop intermediate,while the Ag active sites efficiently electroreduce CO_(2)to the^(*)CO_(bridge)intermediate.The proximity of Cu+/Ag bimetallic sites shortens the distance for C-C bond coupling between the*COatop and^(*)CO_(bridge)intermediates,facilitating the efficient electrocatalytic coupling of CO_(2)to synthesize acetate.DFT analysis indicates that theΔG required for C-C bond coupling on the short-distance Cu+/Ag bimetallic sites of NF@CoMn_(2)O_(4)@Cu_(2)O-Ag is significantly lower than that of NF@CoMn_(2)O_(4)@Cu_(2)O,enabling a high Faradaic efficiency of 64.97%for acetate production at-0.3 V vs.RHE.This study provides an effective strategy for the rational design of synergistic catalysis between heterometallic catalytic sites to efficiently achieve C-C coupling for the synthesis of C2+products.
基金supported by the National Natural Science Foundation of China(No.52370112).
文摘In order to address the evolving emission characteristics of oxygenated volatile organic compounds(OVOCs),it is essential to develop adsorbent materials specifically designed for the efficient adsorption of OVOCs with large kinetic diameters.In this study,we used co-pyrolysis to prepare a series of graded porous carbon materials with well-developed micropores by adjusting the doping ratios of root nodules and pretreated cellulose.The material with root nodule to cellulose mass ratio of 1:1(TCC-RN-1)exhibited the highest saturated adsorption capacity for butyl acetate(834 mg/g).This can be attributed to enhanced pore size distribution from nodule doping,which facilitates the development of a micropore-graded structure.Additionally,the nodules acted as auxiliary activating agents that enhanced the KOH micropore regulation effect during the activation stage,resulting in the highest micropore volume(0.863 cm^(3)/g).The doping of root nodules facilitated the formation of additional defects on the surface of the porous carbon material,leading to a more disordered arrangement that improved pollutant adsorption.Furthermore,TCC-RN-1 demonstrated good thermal stability in an air atmosphere,main-taining a butyl acetate adsorption capacity exceeding 95%after five adsorption-desorption cycles.This indicates its favorable potential for industrial applications.
基金supported by the Qilu University of Technology(Shandong Academy of Sciences),the Basic Research Project of Science,Education and Industry Integration Pilot Project(No.2022PY047).
文摘Photothermal synergistic catalytic systems for treating volatile organic compounds(VOCs)have attracted signif-icant attention due to their energy efficiency and potential to reduce carbon emissions.However,the mechanism underlying the synergistic reaction remains a critical issue.This study introduces a photothermal synergistic system for the removal of ethyl acetate(EA)by synthesizing Cu-doped OMS-2(denoted as Cu-OMS-2).Under ultraviolet-visible(UV–Vis)irradiation in a flow system,the Cu-OMS-2 catalyst exhibited significantly enhanced performance in the EA degradation process,nearly doubling the effectiveness of pure OMS-2,and increasing carbon dioxide yield by 20%.This exceptional performance is attributed to the synergistic effect of increased oxygen vacancies(OV)at OMS-2 active sites and Cu doping,as confirmed by H2-TPR,O_(2)-TPD,and CO consump-tion measurements.This study clarifies the catalytic mechanism of light-assisted thermocatalysis and offers a novel strategy for designing photothermal catalysts with homogeneous Cu-doped nanorods for VOC removal.
基金supported by the Science and Technology Commission of Shanghai Municipality Foundation(No.22230710500)the Interdisciplinary joint research project of Tongji University(No.2023-3-YB-07).
文摘As the core of cathode materials,sensitive metals play important roles in the optimization of acetate production from carbon dioxide(CO_(2))in microbial electrochemical system(MES).In this work,iron(Fe),copper(Cu),and nickel(Ni)as sensitive metal cathode materials were evaluated for CO_(2) conversion in MES.The MES with Feelectrode as a promising electrode material demonstrated a superior CO_(2) reduction performance with a maximum acetate accumulation of 417.9±39.2 mg/L,which was 1.5 and 1.7 folds higher than that in the Ni-electrode and Cu-electrode groups,respectively.Furthermore,an outstanding electron recovery efficiency of 67.7%was shown in the Fe-electrode group.The electron transfer between electrode-suspended sludge was systematically cross-evaluated by the electrochemical behavior and extracellular polymeric substances.The Fe-electrode group had the highest electron transfer rate with 0.194 s-1(k_(app)),which was 17.6 and 21.5 times higher than that of the Cu-and Ni-electrode groups,respectively.Fe-electrode was beneficial for reducing electrochemical impedance between the electrode and suspended sludge.Additionally,redox substances in extracellular polymeric substances of the Fe-electrode group were increased,implying more favorable electron transport dynamics.Simultaneously,enrichments of functional bacteria Acetoanerobium and increased key enzymes involved in the carbonyl pathway of the Fe-electrode group were observed,which also promoted CO_(2) conversion in MES.This study provides a perspective on evaluating the promising sensitive metal electrode material for the process of CO_(2) valorization in MES and offers a reference for the subsequent electrode modification.
