One-step anodic acetoxylation of benzene to phenyl acetate was studied in acetic acid-water solution using a one-compartment electrochemical cell in galvanostatic mode. Compared to the anhydrous system, the addition o...One-step anodic acetoxylation of benzene to phenyl acetate was studied in acetic acid-water solution using a one-compartment electrochemical cell in galvanostatic mode. Compared to the anhydrous system, the addition of water improved the current efficiency for the electrosynthesis of phenyl acetate. The maximum efficiency reached 4.8% with the selectivity of 96% to phenyl acetate when the electrolysis was carried out under the optimal conditions. The investigation also indicated that the concentration of phenyl acetate increased linearly in 12 h and reached 1.07 g/L with the selectivity of 95%. Cyclic voltammetry experiments showed that the adsorption of benzene at Pt anode enhanced by the addition of water was critical to the formation of phenyl acetate. An activated benzene mechanism was proposed for the anodic acytoxylation, and the analysis of gas products demonstrated that Kolbe reaction was the main side reaction.展开更多
The knowledge of solubility of a salt in either the pure solvent or blend solvent is of great importance for studying or operating the crystallization,extraction,and distillation processes.The solubility of sodium ace...The knowledge of solubility of a salt in either the pure solvent or blend solvent is of great importance for studying or operating the crystallization,extraction,and distillation processes.The solubility of sodium acetate(NaAc)in four pure solvents(water,ethanol,acetic acid and 2,2,2-trifluoroethanol)and four binary solvents(water–ethanol,water-acetic acid,acetic acid–ethanol,and acetic acid-ethyl acetate)were measured by using the laser dynamic method at temperatures from 288.15 K to 338.15 K at 0.1 MPa.The results showed that the solubility of NaAc was influenced by either the solution temperature or solvent composition.The aqueous sodium acetate solution possessed the maximal solubility under the experimental conditions.The solubility of NaAc in 2,2,2-trifluoroethanol was found to be decreased with the increase of the solution temperature.While,the solubilities of NaAc in other seven solvents increased as the solution temperature was elevated.Besides,five correlation models,including the van’t Hoff model,modified Apelblat model,Yaws model,λh model,and modified Apelblat-Jouyban-Acree model were used to correlate the solubility data of those sodium acetate solutions with acceptable deviation,respectively.Finally,van’t Hoff analysis method was selected to analyze the change law of thermodynamic properties of a salt during the dissolution process.展开更多
Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorp...Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA.展开更多
The large-scale industrial production of acetic acid (HAc) from carbonylation of methanol has enabled intense research interest from direct hydrogenation of HAc to acetaldehyde (AA).Herein,a series of cerium-iron oxid...The large-scale industrial production of acetic acid (HAc) from carbonylation of methanol has enabled intense research interest from direct hydrogenation of HAc to acetaldehyde (AA).Herein,a series of cerium-iron oxide solid solution supported metallic cobalt catalysts were prepared by modified sol-gel method and were applied in gas-phase hydrogenation of HAc to AA.A synergistic effect between the hydrogenation metal cobalt and Ce-Fe oxide solid solution is revealed.Specifically,oxygen vacancies provide the active sites for adsorption of HAc,while highly uniformly dispersed metallic Co adsorbs H2 and activates the reduction of HAc into AA.Moreover,the metallic Co can also assist the cyclical conversion between Fe3+/Fe2+ and Ce3+/Ce4+ on the surface of Ce1.xFexO2-δ supports.The unique effect substantially enhances the ability of the support material to rapidly capture oxygen atoms from HAc.It is found that the catalyst of 5% Co/Ce0.8Fe0.2O2-δ with the highest concentration of oxygen vacancy presents the best catalytic performance (i.e.acetaldehyde yield reaches 49.9%) under the optimal reaction conditions (i.e.623 K and H2 flow rate =10 mL/min).This work indicates that the Co/Ce-Fe oxide solid solution catalyst can be potentially used for the selective hydrogenation from HAc to AA.The synergy between the metallic Co and Ce1-xFexO2-δ revealed can be extended to the design of other composite catalysts.展开更多
The mechanism for the production of acetic acid from ethanol and water mixture catalyzed by iridium catalyst has been theoretically investigated.The cooperation of the iridium center and bpyO ligand is highlighted,whi...The mechanism for the production of acetic acid from ethanol and water mixture catalyzed by iridium catalyst has been theoretically investigated.The cooperation of the iridium center and bpyO ligand is highlighted,which plays an important role in the catalytic activity.The hydrogen release from the iridium center is the rate-determining step,with an energy barrier of 22.5 kcal/mol.The electronic structure analysis suggests electron-donating substituents could decrease the energy barrier.展开更多
Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a l...Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a low temperature showed high catalytic activities.When calcined at high temperatures,the catalyst with Ce0.9Cu0.1O1.9 solid solution as precursor remained a high activity,while the catalyst with metal nitrates as precursors exhibited a suppressed reactivity.Therefore,the catalyst prepared with th...展开更多
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.21021001, No.20502017, and No.20872102）, and the Program for Changjiang Scholars and Innovative Research Team in University （No.0846）. The Analytic and Testing Center of Sichuan University are greatly appreciated.
文摘One-step anodic acetoxylation of benzene to phenyl acetate was studied in acetic acid-water solution using a one-compartment electrochemical cell in galvanostatic mode. Compared to the anhydrous system, the addition of water improved the current efficiency for the electrosynthesis of phenyl acetate. The maximum efficiency reached 4.8% with the selectivity of 96% to phenyl acetate when the electrolysis was carried out under the optimal conditions. The investigation also indicated that the concentration of phenyl acetate increased linearly in 12 h and reached 1.07 g/L with the selectivity of 95%. Cyclic voltammetry experiments showed that the adsorption of benzene at Pt anode enhanced by the addition of water was critical to the formation of phenyl acetate. An activated benzene mechanism was proposed for the anodic acytoxylation, and the analysis of gas products demonstrated that Kolbe reaction was the main side reaction.
基金Supported by the National Natural Science Foundation of China(52076026,51606024,51776029)the Project of the Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education,China(LOEC-201904)。
文摘The knowledge of solubility of a salt in either the pure solvent or blend solvent is of great importance for studying or operating the crystallization,extraction,and distillation processes.The solubility of sodium acetate(NaAc)in four pure solvents(water,ethanol,acetic acid and 2,2,2-trifluoroethanol)and four binary solvents(water–ethanol,water-acetic acid,acetic acid–ethanol,and acetic acid-ethyl acetate)were measured by using the laser dynamic method at temperatures from 288.15 K to 338.15 K at 0.1 MPa.The results showed that the solubility of NaAc was influenced by either the solution temperature or solvent composition.The aqueous sodium acetate solution possessed the maximal solubility under the experimental conditions.The solubility of NaAc in 2,2,2-trifluoroethanol was found to be decreased with the increase of the solution temperature.While,the solubilities of NaAc in other seven solvents increased as the solution temperature was elevated.Besides,five correlation models,including the van’t Hoff model,modified Apelblat model,Yaws model,λh model,and modified Apelblat-Jouyban-Acree model were used to correlate the solubility data of those sodium acetate solutions with acceptable deviation,respectively.Finally,van’t Hoff analysis method was selected to analyze the change law of thermodynamic properties of a salt during the dissolution process.
文摘Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA.
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 21576050 and 51602052)the Jiangsu Provincial Natural Science Foundation of China (BK20150604)+2 种基金the Fundamental Research Funds for the Central Universities of China (Nos. 3207045403,3207045409, 3207046414)Foundation of Jiangsu Key Laboratory for Biomass Energy and Material (JSBEM201805)Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and Zhongying Young Scholars of Southeast University.
文摘The large-scale industrial production of acetic acid (HAc) from carbonylation of methanol has enabled intense research interest from direct hydrogenation of HAc to acetaldehyde (AA).Herein,a series of cerium-iron oxide solid solution supported metallic cobalt catalysts were prepared by modified sol-gel method and were applied in gas-phase hydrogenation of HAc to AA.A synergistic effect between the hydrogenation metal cobalt and Ce-Fe oxide solid solution is revealed.Specifically,oxygen vacancies provide the active sites for adsorption of HAc,while highly uniformly dispersed metallic Co adsorbs H2 and activates the reduction of HAc into AA.Moreover,the metallic Co can also assist the cyclical conversion between Fe3+/Fe2+ and Ce3+/Ce4+ on the surface of Ce1.xFexO2-δ supports.The unique effect substantially enhances the ability of the support material to rapidly capture oxygen atoms from HAc.It is found that the catalyst of 5% Co/Ce0.8Fe0.2O2-δ with the highest concentration of oxygen vacancy presents the best catalytic performance (i.e.acetaldehyde yield reaches 49.9%) under the optimal reaction conditions (i.e.623 K and H2 flow rate =10 mL/min).This work indicates that the Co/Ce-Fe oxide solid solution catalyst can be potentially used for the selective hydrogenation from HAc to AA.The synergy between the metallic Co and Ce1-xFexO2-δ revealed can be extended to the design of other composite catalysts.
基金This work is supported by the National Natural Science Foundation of China (No. 21672018)the Fundamental Research Funds for the Central Universities (No. XK1802-6). We thank the National Supercomputing Center in Tianjin (TianHe-1) for providing part of the computational sources.
文摘The mechanism for the production of acetic acid from ethanol and water mixture catalyzed by iridium catalyst has been theoretically investigated.The cooperation of the iridium center and bpyO ligand is highlighted,which plays an important role in the catalytic activity.The hydrogen release from the iridium center is the rate-determining step,with an energy barrier of 22.5 kcal/mol.The electronic structure analysis suggests electron-donating substituents could decrease the energy barrier.
基金supported by the Plan Project of Science and Technology in Zhejiang Province of China (2008C21020)
文摘Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a low temperature showed high catalytic activities.When calcined at high temperatures,the catalyst with Ce0.9Cu0.1O1.9 solid solution as precursor remained a high activity,while the catalyst with metal nitrates as precursors exhibited a suppressed reactivity.Therefore,the catalyst prepared with th...
