Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate o...Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm.展开更多
Micro-interface intensified reactor(MIR)can be applied in series/parallel in the absorption of CO_(2)in industrial gases by Na_(2)CO_(3)due to the ability to produce large numbers of stable microbubbles.This work focu...Micro-interface intensified reactor(MIR)can be applied in series/parallel in the absorption of CO_(2)in industrial gases by Na_(2)CO_(3)due to the ability to produce large numbers of stable microbubbles.This work focuses on the variation pattern of mass transfer characteristics parameters of the reaction gas in Na_(2)CO_(3) solution under the influence of different solution properties and operating parameters in the reaction of CO_(2)absorption by Na2CO3.The mass transfer characteristics parameters include bubble Sauter mean diameter,gas holdup,interfacial area,liquid side mass transfer coefficient,and liquid side volume mass transfer coefficient kLa.The solution properties and operating parameters include Na2CO3 concentration(0.05–2.0 mol·L^(-1)),superficial gas velocity(0.00221–0.01989 m·s^(-1)),superficial liquid velocity(0.00332–0.02984 m·s^(-1)),and ionic strength(1.42456–1.59588 mol·kg^(-1)).And volumetric mass transfer coeffi-cients kLa and superficial reaction rates r of the MIR and the bubble column reactor are compared in the reaction of sodium carbonate absorption of carbon dioxide,and the former shows a greater improvement under different solution properties and operating parameters.The enhanced role of MIR in mass transfer in non-homogeneous reactions is verified and the feasibility of industrial practical applications of MIR is demonstrated.展开更多
Metal-free carbon-based catalysts exhibit diverse electrocatalytic performances in CO_(2) reduction reaction(CO_(2)RR),but the attributions and contributions of active sites are still confusing to date.Herein,the hier...Metal-free carbon-based catalysts exhibit diverse electrocatalytic performances in CO_(2) reduction reaction(CO_(2)RR),but the attributions and contributions of active sites are still confusing to date.Herein,the hierarchical carbon nanocages(hCNC)doped with different heteroatoms(B,N,P,S)are prepared to examine the impact of dopants on the competitive CO_(2)RR and hydrogen evolution reaction(HER).The hCNC and P-doped hCNC show little CO_(2)RR activity,B-and S-doped hCNC show weak CO_(2)RR activity,while N-doped hCNC presents high CO_(2)RR activity.The CO Faradaic efficiency(FECO)of N-containing hCNC increases almost linearly with increasing the N content,even with the co-existing B or P.S and SN-doped hCNC more facilitate the HER.16 doping configurations are constructed,and up to 53 sites are examined CO_(2) H2O H2 CO*H*COOH*CO for the electrochemical activities with a constant potential modelling method.The pyridinic-N(N^(*))is the best active site for CO_(2)RR to CO,while CBO_(2)H_(2)-1(αC^(*)),CBO_(2)H_(2)-2(γC^(*)),NO-1(βC^(*)),PO_(2)H-3(αC^(*))and SO_(3)H-3(δC^(*))are active for HER.The optimized FECO achieves 83.6%for N-doped hCNC with 9.54 at.%nitrogen,and S-doped hCNC reaches ca.30 mA·cm^(-2) current density for HER.This study unveils the structure-performance correlation of heteroatom-doped hCNC,which is conducive to the rational design of advanced metal-free carbon-based catalysts.展开更多
Efficient,durable and economic electrocatalysts are crucial for commercializing water electrolysis technology.Herein,we report an advanced bifunctional electrocatalyst for alkaline water splitting by growing NiFe-laye...Efficient,durable and economic electrocatalysts are crucial for commercializing water electrolysis technology.Herein,we report an advanced bifunctional electrocatalyst for alkaline water splitting by growing NiFe-layered double hydroxide(NiFe-LDH)nanosheet arrays on the conductive NiMo-based nanorods deposited on Ni foam to form a three-dimensional(3D)architecture,which exhibits exceptional performances for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In overall water splitting,only the low operation voltages of 1.45/1.61 V are required to reach the current density of 10/500 mA·cm^(-2),and the continuous water splitting at an industrial-level current density of 500 mA·cm^(-2) shows a negligible degradation(1.8%)of the cell voltage over 1000 h.The outstanding performance is ascribed to the synergism of the HER-active NiMo-based nanorods and the OER-active NiFe-LDH nanosheet arrays of the hybridized 3D architecture.Specifically,the dense NiFe-LDH nanosheet arrays enhance the local pH on cathode by retarding OH-diffusion and enlarge the electrochemically active surface area on anode,while the conductive NiMo-based nanorods on Ni foam much decrease the charge-transfer resistances of both electrodes.This study provides an efficient strategy to explore advanced bifunctional electrocatalysts for overall water splitting by rationally hybridizing HER-and OER-active components.展开更多
Potassium-ion batteries(PIBs)are appealing alternatives to conventional lithium-ion batteries(LIBs)because of their wide potential window,fast ionic conductivity in the electrolyte,and reduced cost.However,PIBs suffer...Potassium-ion batteries(PIBs)are appealing alternatives to conventional lithium-ion batteries(LIBs)because of their wide potential window,fast ionic conductivity in the electrolyte,and reduced cost.However,PIBs suffer from sluggish K+reaction kinetics in electrode materials,large volume expansion of electroactive materials,and the unstable solid electrolyte interphase.Various strategies,especially in terms of electrode design,have been proposed to address these issues.In this review,the recent progress on advanced anode materials of PIBs is systematically discussed,ranging from the design principles,and nanoscale fabrication and engineering to the structure-performance relationship.Finally,the remaining limitations,potential solutions,and possible research directions for the development of PIBs towards practical applications are presented.This review will provide new insights into the lab development and real-world applications of PIBs.展开更多
基金financial support of the National Natural Science Foundation of China(21776122).
文摘Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm.
基金Natural Science Foundation of Jiangsu Province(BK20210185)National Natural Science Foundation of China(22278202).
文摘Micro-interface intensified reactor(MIR)can be applied in series/parallel in the absorption of CO_(2)in industrial gases by Na_(2)CO_(3)due to the ability to produce large numbers of stable microbubbles.This work focuses on the variation pattern of mass transfer characteristics parameters of the reaction gas in Na_(2)CO_(3) solution under the influence of different solution properties and operating parameters in the reaction of CO_(2)absorption by Na2CO3.The mass transfer characteristics parameters include bubble Sauter mean diameter,gas holdup,interfacial area,liquid side mass transfer coefficient,and liquid side volume mass transfer coefficient kLa.The solution properties and operating parameters include Na2CO3 concentration(0.05–2.0 mol·L^(-1)),superficial gas velocity(0.00221–0.01989 m·s^(-1)),superficial liquid velocity(0.00332–0.02984 m·s^(-1)),and ionic strength(1.42456–1.59588 mol·kg^(-1)).And volumetric mass transfer coeffi-cients kLa and superficial reaction rates r of the MIR and the bubble column reactor are compared in the reaction of sodium carbonate absorption of carbon dioxide,and the former shows a greater improvement under different solution properties and operating parameters.The enhanced role of MIR in mass transfer in non-homogeneous reactions is verified and the feasibility of industrial practical applications of MIR is demonstrated.
基金This work was jointly supported by the National Key Research and Development Program of China(No.2021YFA1500900)the National Natural Science Foundation of China(No.52071174)the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005)。
文摘Metal-free carbon-based catalysts exhibit diverse electrocatalytic performances in CO_(2) reduction reaction(CO_(2)RR),but the attributions and contributions of active sites are still confusing to date.Herein,the hierarchical carbon nanocages(hCNC)doped with different heteroatoms(B,N,P,S)are prepared to examine the impact of dopants on the competitive CO_(2)RR and hydrogen evolution reaction(HER).The hCNC and P-doped hCNC show little CO_(2)RR activity,B-and S-doped hCNC show weak CO_(2)RR activity,while N-doped hCNC presents high CO_(2)RR activity.The CO Faradaic efficiency(FECO)of N-containing hCNC increases almost linearly with increasing the N content,even with the co-existing B or P.S and SN-doped hCNC more facilitate the HER.16 doping configurations are constructed,and up to 53 sites are examined CO_(2) H2O H2 CO*H*COOH*CO for the electrochemical activities with a constant potential modelling method.The pyridinic-N(N^(*))is the best active site for CO_(2)RR to CO,while CBO_(2)H_(2)-1(αC^(*)),CBO_(2)H_(2)-2(γC^(*)),NO-1(βC^(*)),PO_(2)H-3(αC^(*))and SO_(3)H-3(δC^(*))are active for HER.The optimized FECO achieves 83.6%for N-doped hCNC with 9.54 at.%nitrogen,and S-doped hCNC reaches ca.30 mA·cm^(-2) current density for HER.This study unveils the structure-performance correlation of heteroatom-doped hCNC,which is conducive to the rational design of advanced metal-free carbon-based catalysts.
基金supported by the National Key Research and Development Program of China(No.2021YFA1500900)the National Natural Science Foundation of China(Nos.52071174,21832003,21972061)+1 种基金the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005)the Foundation of Science and Technology of Suzhou(No.SYC2022102).
文摘Efficient,durable and economic electrocatalysts are crucial for commercializing water electrolysis technology.Herein,we report an advanced bifunctional electrocatalyst for alkaline water splitting by growing NiFe-layered double hydroxide(NiFe-LDH)nanosheet arrays on the conductive NiMo-based nanorods deposited on Ni foam to form a three-dimensional(3D)architecture,which exhibits exceptional performances for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In overall water splitting,only the low operation voltages of 1.45/1.61 V are required to reach the current density of 10/500 mA·cm^(-2),and the continuous water splitting at an industrial-level current density of 500 mA·cm^(-2) shows a negligible degradation(1.8%)of the cell voltage over 1000 h.The outstanding performance is ascribed to the synergism of the HER-active NiMo-based nanorods and the OER-active NiFe-LDH nanosheet arrays of the hybridized 3D architecture.Specifically,the dense NiFe-LDH nanosheet arrays enhance the local pH on cathode by retarding OH-diffusion and enlarge the electrochemically active surface area on anode,while the conductive NiMo-based nanorods on Ni foam much decrease the charge-transfer resistances of both electrodes.This study provides an efficient strategy to explore advanced bifunctional electrocatalysts for overall water splitting by rationally hybridizing HER-and OER-active components.
基金This project was financially supported by the National Key Research and Development Program of China(No.2017YFA0208200)the National Natural Science Foundation of China(Nos.22005003,22022505,and 21872069)+4 种基金the Fundamental Research Funds for the Central Universities(Nos.0205-14380219 and 0205-14913212)the Scientific Research Foundation of Anhui University of Technology for Talent Introduction(No.DT19100069)the Yong Scientific Research Foundation of Anhui University of Technology(No.QZ202003)the Natural Science Foundation of Jiangsu Province(No.BK20180008)the Shenzhen Fundamental Research Program of Science,Technology,and Innovation Commission of Shenzhen Municipality(No.JCYJ20180307155007589).
文摘Potassium-ion batteries(PIBs)are appealing alternatives to conventional lithium-ion batteries(LIBs)because of their wide potential window,fast ionic conductivity in the electrolyte,and reduced cost.However,PIBs suffer from sluggish K+reaction kinetics in electrode materials,large volume expansion of electroactive materials,and the unstable solid electrolyte interphase.Various strategies,especially in terms of electrode design,have been proposed to address these issues.In this review,the recent progress on advanced anode materials of PIBs is systematically discussed,ranging from the design principles,and nanoscale fabrication and engineering to the structure-performance relationship.Finally,the remaining limitations,potential solutions,and possible research directions for the development of PIBs towards practical applications are presented.This review will provide new insights into the lab development and real-world applications of PIBs.
