Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent f...Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.展开更多
The structural modulation of the inner Helmholtz layer is crucial to enhance the cycling stability of Zn anode interface.A water-rich inner Helmholtz layer normally induces uncontrollable zinc dendrites,hydrogen evolu...The structural modulation of the inner Helmholtz layer is crucial to enhance the cycling stability of Zn anode interface.A water-rich inner Helmholtz layer normally induces uncontrollable zinc dendrites,hydrogen evolution and corrosion,severely compromising the cycle life of the zinc anode.Therefore,in this work,green and non-toxic dipropylene glycol dimethyl ether(DMM)is used as an additive to remodel the inner Helmholtz layer.Both experimental and computational results show that DMM is zincophilic and can preferential adsorb on the zinc surface for the occupation of the inner Helmholtz layer.Meanwhile,DMM contains two hydrophobic methyl groups,which can repel water molecules remaining after solvent removal,and build a lean-water inner Helmholtz layer to avoid continuous contact between water molecules and zinc anode.The quartz crystal microbalance with dissipation test intuitively and accurately reflected the adsorption behavior of DMM on the surface of zinc anode,and realized the leap from qualitative analysis to quantitative analysis.The Zn//Zn symmetric cells with DMM electrolytes have a stable cycle life of over 1100 cycles at 2 mA cm^(-2) and 0.5 mAh cm^(-2).In addition,Zn//PANI cell with DMM electrolyte can maintain 90%capacity retention over 1000 cycles at 1 A g^(-1).展开更多
基金Supported by the Natural Science Foundation of Shanxi Province(202203021221303)the Science and Technology Major Project of Shanxi Province(202005D121002)the Science and Technology Cooperation and Communication Project of Shanxi Province(202304041101016)。
文摘Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.
基金support from funding of Natural Science Foundation of Top Talent of SZTU(Grant No.GDRC202315)Guangdong Basic and Applied Basic Research Foundation(2024A1515012363)+3 种基金T.Y.is thankful for support from the project of the research on the electrochemical reaction mechanism of the anode of medium-low temperature direct ammonia SOFCs(2022ZDZX3024)The authors would also like to acknowledge financial support from Shenzhen Municipality under Stability Support Program of Shenzhen Colleges and Universities(Grant No.GXWD20220817150352006)Shenzhen Science and Technology Program(Grant No.RCBS20221008093222009)C.S.is thankful for support from the National Natural Science Foundation of China(Jiangsu University of Science and Technology-22309067,2174255,Shenzhen Technology University-22309036).
文摘The structural modulation of the inner Helmholtz layer is crucial to enhance the cycling stability of Zn anode interface.A water-rich inner Helmholtz layer normally induces uncontrollable zinc dendrites,hydrogen evolution and corrosion,severely compromising the cycle life of the zinc anode.Therefore,in this work,green and non-toxic dipropylene glycol dimethyl ether(DMM)is used as an additive to remodel the inner Helmholtz layer.Both experimental and computational results show that DMM is zincophilic and can preferential adsorb on the zinc surface for the occupation of the inner Helmholtz layer.Meanwhile,DMM contains two hydrophobic methyl groups,which can repel water molecules remaining after solvent removal,and build a lean-water inner Helmholtz layer to avoid continuous contact between water molecules and zinc anode.The quartz crystal microbalance with dissipation test intuitively and accurately reflected the adsorption behavior of DMM on the surface of zinc anode,and realized the leap from qualitative analysis to quantitative analysis.The Zn//Zn symmetric cells with DMM electrolytes have a stable cycle life of over 1100 cycles at 2 mA cm^(-2) and 0.5 mAh cm^(-2).In addition,Zn//PANI cell with DMM electrolyte can maintain 90%capacity retention over 1000 cycles at 1 A g^(-1).
