The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in ele...The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to date.Herein,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing treatment.Specifically,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V vs.reversible hydrogen electrode,outperforming than those of FCC Pd Cu MAs.Under the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR performance.Our work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.展开更多
The benzene and acetonitrile azeotropic mixture was proposed to be separated by extractive distillation using an ionic liquid(IL)as the entrainer.The suitable IL was selected by the COSMO-RS model,and 1-ethyl-3-methyl...The benzene and acetonitrile azeotropic mixture was proposed to be separated by extractive distillation using an ionic liquid(IL)as the entrainer.The suitable IL was selected by the COSMO-RS model,and 1-ethyl-3-methylimidazolium tetrafluoroborate([EMIM][BF_(4)])was considered as the suitable entrainer mainly due to its high selectivity,low viscosity,and low price.The experimental vapor pressure data of the IL-containing systems(benzene+[EMIM][BF_(4)]and acetonitrile+[EMIM][BF_(4)])were measured in the full concentration range.The results show that acetonitrile has a stronger interaction with IL than benzene,and the low deviations between the experimental and UNIFAC predicted values show the reliability of the UNFIAC model.The UNIFAC predicted vapor-liquid equilibrium data of the benzene+acetonitrile+dimethyl sulfoxide(DMSO)/[EMIM][BF_(4)]system show that the relative volatility of benzene to acetonitrile is higher when the entrainer is[EMIM][BF_(4)].The process simulation results show that[EMIM][BF_(4)]can reduce the material and energy consumptions compared with DMSO.展开更多
In the present work,a comparative study of the extractive distillation and pressure swing distillation for methanol-acetonitrile separation is performed for the first time.Different separation alternatives,including t...In the present work,a comparative study of the extractive distillation and pressure swing distillation for methanol-acetonitrile separation is performed for the first time.Different separation alternatives,including the conventional extractive distillation,the extractive distillation with vapor or liquid side-stream,the pressure-swing distillation with or without full heat integration,and the heat-pump assisted pressure-swing distillation are rigorously simulated and optimized based on the minimum total annual cost(TAC)via the sequential iterative strategy.The results show that TAC and CO2 emission of the new extractive distillation with vapor side-stream(Vapor-SED)are similar to those of the extractive distillation with liquid side-stream(Liquid-SED).Furthermore,the Vapor-SED and Liquid-SED can achieve 30.01%and 30.56%reduction in TAC and 23.32%and 23.49%reduction in CO2 emission,respectively,over the most competitive fully heat-integrated PSD configuration.Hence,the extractive distillation with vapor or liquid side-stream appears to be a better option economically and environmentally for the separation of methanol and acetonitrile.展开更多
The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibit...The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.展开更多
A femtosecond optical Kerr effect experiment has been used to study the dynamic process of third-order optical nonlinearity for organic solvents acetone,acetonitrile,alcohol,benzene,chloroform,dichlomathane,dimenthyl-...A femtosecond optical Kerr effect experiment has been used to study the dynamic process of third-order optical nonlinearity for organic solvents acetone,acetonitrile,alcohol,benzene,chloroform,dichlomathane,dimenthyl-sulfoxande,dioxane,ethanol,and methanol,etc.The nonlinear refractive index for the solvents at femtosecond time scale was measured.展开更多
Lithium-selenium(Li-Se) battery is a promising system with high theoretical gravimetric and volumetric energy densities, while its long-term cyclability is hard to realize, especially when a practical Se cathode with ...Lithium-selenium(Li-Se) battery is a promising system with high theoretical gravimetric and volumetric energy densities, while its long-term cyclability is hard to realize, especially when a practical Se cathode with high Se content, high Se loading, and high density is employed. The main obstacles are the sluggish conversion kinetics of the dense Se cathodes and the continuous deterioration of the Li-metal anodes.Here, by introducing an acetonitrile(AN)-based electrolyte and replacing the Li electrode with a lithiated graphite, we successfully build a hybrid conversion-intercalation system using a high-content(80 wt%),decent-loading(3.0 mg cm^(-2)), and low-porosity(44%) Se cathode. The as-designed lithiated graphite||Se(LG||Se) cell demonstrated a high Se utilization(97.4%), a long cycle life(3000 cycles), and an ultrahigh average Coulombic efficiency(99.98%). The cell also works well under lean-electrolyte(2 l L mg^(-1)) condition and shows outstanding safety performance in the nail-penetrating test. The combination affords the competitive comprehensive performances, including high volumetric and gravimetric energy densities, long cycling life, and superb safety of the LG||Se cell. In addition, with a newly-designed threeelectrode pouch cell, the lithiation of the graphite anodes could be done with an in-situ lithiation process,indicating the high potential of the as-proposed LG||Se cell for the practical applications.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52161135302,22105087)the Postdoctoral Research Foundation of China(Grant No.2022M721360)the Natural Science Foundation of Jiangsu Province(Grant No.BK20210446)。
文摘The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to date.Herein,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing treatment.Specifically,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V vs.reversible hydrogen electrode,outperforming than those of FCC Pd Cu MAs.Under the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR performance.Our work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.
基金financially supported by the National Key R&D Program of China(no.2018YFB0604902)
文摘The benzene and acetonitrile azeotropic mixture was proposed to be separated by extractive distillation using an ionic liquid(IL)as the entrainer.The suitable IL was selected by the COSMO-RS model,and 1-ethyl-3-methylimidazolium tetrafluoroborate([EMIM][BF_(4)])was considered as the suitable entrainer mainly due to its high selectivity,low viscosity,and low price.The experimental vapor pressure data of the IL-containing systems(benzene+[EMIM][BF_(4)]and acetonitrile+[EMIM][BF_(4)])were measured in the full concentration range.The results show that acetonitrile has a stronger interaction with IL than benzene,and the low deviations between the experimental and UNIFAC predicted values show the reliability of the UNFIAC model.The UNIFAC predicted vapor-liquid equilibrium data of the benzene+acetonitrile+dimethyl sulfoxide(DMSO)/[EMIM][BF_(4)]system show that the relative volatility of benzene to acetonitrile is higher when the entrainer is[EMIM][BF_(4)].The process simulation results show that[EMIM][BF_(4)]can reduce the material and energy consumptions compared with DMSO.
文摘In the present work,a comparative study of the extractive distillation and pressure swing distillation for methanol-acetonitrile separation is performed for the first time.Different separation alternatives,including the conventional extractive distillation,the extractive distillation with vapor or liquid side-stream,the pressure-swing distillation with or without full heat integration,and the heat-pump assisted pressure-swing distillation are rigorously simulated and optimized based on the minimum total annual cost(TAC)via the sequential iterative strategy.The results show that TAC and CO2 emission of the new extractive distillation with vapor side-stream(Vapor-SED)are similar to those of the extractive distillation with liquid side-stream(Liquid-SED).Furthermore,the Vapor-SED and Liquid-SED can achieve 30.01%and 30.56%reduction in TAC and 23.32%and 23.49%reduction in CO2 emission,respectively,over the most competitive fully heat-integrated PSD configuration.Hence,the extractive distillation with vapor or liquid side-stream appears to be a better option economically and environmentally for the separation of methanol and acetonitrile.
基金financially supported by the National Natural Science Foundation of China (No. 21573101)the Liaoning Provincial Natural Science Foundation (No. 2014020107)+1 种基金the Program for Liaoning Excellent Talents in Universities (No. LJQ2014041)sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (SRF for ROCS, SEM)
文摘The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.
基金Supported by the National Natural Science Foundation of China under Grant No.19525412National Science and Technology Commission of China。
文摘A femtosecond optical Kerr effect experiment has been used to study the dynamic process of third-order optical nonlinearity for organic solvents acetone,acetonitrile,alcohol,benzene,chloroform,dichlomathane,dimenthyl-sulfoxande,dioxane,ethanol,and methanol,etc.The nonlinear refractive index for the solvents at femtosecond time scale was measured.
基金supported by the National Natural Science Foundation of China under Grant No. 51802225the funding from the State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology (P2020-001)。
文摘Lithium-selenium(Li-Se) battery is a promising system with high theoretical gravimetric and volumetric energy densities, while its long-term cyclability is hard to realize, especially when a practical Se cathode with high Se content, high Se loading, and high density is employed. The main obstacles are the sluggish conversion kinetics of the dense Se cathodes and the continuous deterioration of the Li-metal anodes.Here, by introducing an acetonitrile(AN)-based electrolyte and replacing the Li electrode with a lithiated graphite, we successfully build a hybrid conversion-intercalation system using a high-content(80 wt%),decent-loading(3.0 mg cm^(-2)), and low-porosity(44%) Se cathode. The as-designed lithiated graphite||Se(LG||Se) cell demonstrated a high Se utilization(97.4%), a long cycle life(3000 cycles), and an ultrahigh average Coulombic efficiency(99.98%). The cell also works well under lean-electrolyte(2 l L mg^(-1)) condition and shows outstanding safety performance in the nail-penetrating test. The combination affords the competitive comprehensive performances, including high volumetric and gravimetric energy densities, long cycling life, and superb safety of the LG||Se cell. In addition, with a newly-designed threeelectrode pouch cell, the lithiation of the graphite anodes could be done with an in-situ lithiation process,indicating the high potential of the as-proposed LG||Se cell for the practical applications.
