For a cyclone, it is possible to improve separation efficiency and reduce pressure drop by increasing the cyclone height. However, an exceeded height increase could result in a dramatical drop in separation efficiency...For a cyclone, it is possible to improve separation efficiency and reduce pressure drop by increasing the cyclone height. However, an exceeded height increase could result in a dramatical drop in separation efficiency. In this study, experimental and computational fluid dynamics simulation results exhibit that the introduction of an apex cone at the dust outlet could avoid the risk of separation efficiency drop but lead to a continuous reducing of the pressure drop. Generally, the optimal cyclone height should be closely related to the natural vortex length. While, when the vortex end contracts into the separation space in the cyclone with an exceeded height, severe back-mixing of particles always occurs, which will result in the decrease of separation efficiency. Herein, it is found that when an apex cone is installed at the dust outlet, the vortex end can be grasped by the cone so as to weaken the back-mixing of particles.Meanwhile, the introduction of this apex cone can enhance the secondary separation to capture the back-mixed particles again so as to protect the efficiency. In addition, it is found that the enhanced secondary separation could come from either the stagnant current of axial velocity in the center or the improved tangential velocity of inner vortex whereas the forcibly extending the length of vortex to exceed its natural length will not significantly increase efficiency.展开更多
Soybean can serve as an efficient carbon and nitrogen source for in-situ fabrication of efficient composite electrocatalysts with conductive nitrogen-doped carbon(N-C)material.In this study,the iron-doped cobalt nitri...Soybean can serve as an efficient carbon and nitrogen source for in-situ fabrication of efficient composite electrocatalysts with conductive nitrogen-doped carbon(N-C)material.In this study,the iron-doped cobalt nitride/phosphide(Fe-Co_(3)N/CoP)nanosheet was composited with a conductive N-C material by using soybean as C and N source,as well as NH3 as additional nitrogen source.During the nitridation process of Fe-Co_(3)N,N-C bond was formed as a newly generated Co(Fe)-N-C active sites.Therefore,it fabricates a good microscopic contact interface between the catalyst and carbon material for charge transfer.Besides,the introduction of Fe-CoP by partially phosphating Fe-Co_(3)N further improved the OER activity due to the high catalytic activity of Co sites with high valence state.As a result,the obtained electrocatalyst exhibited overpotentials as low as 285 and 390 mV for supporting 10 and 100 mA/cm2 current densities.This work indicates that the design of materials with good interfaces could be an effective approach for the preparation of electrocatalysts for water electrolysis.展开更多
Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield...Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield as well as low selectivity.Herein,effective increase of higher alcohols proportion in the product is realized by direct conversion of syngas over electronically-modulated ZnO semiconductor via Cu doping.It is considered that the lower Fermi level and narrower band gap of catalysts by embedding Cu^(2+)into ZnO lattice could facilitate donor reaction by boosting the process for the reactants to obtain electrons on the catalyst surface for the formation of CH_(x) species and carbon chain growth,in which the Cu doping on ZnO lattice play important role in the promotion of CO adsorption.As a result,4 mol%Cu doped ZnO exhibits a highest C_(2+) OH/ROH fraction of 48.1%.Selectivity of catalysts from straight chain alcohol is better than from branch chain alcohol,which is different from promoted Cu/ZnO based catalyst.However,over-doping of Cu(7 mol%)on ZnO results in the aggregation Cu species on ZnO surface,leading to a sharp decrease of higher alcohols proportion to 3.2%.The results shed light on the nature that a direct correlation between semiconductor Fermi level and synthesis of higher alcohols,and the semiconductor-based catalysts mainly accelerate the hydrogenation reactions by enhancing thermally excited electron transfer.展开更多
Amorphous high-entropy materials with abundant defects,coordinatively unsaturated sites,and loosely bonded atoms could exhibit excellent electrocatalytic performance.However,how to fabricate such ma-terials with nanos...Amorphous high-entropy materials with abundant defects,coordinatively unsaturated sites,and loosely bonded atoms could exhibit excellent electrocatalytic performance.However,how to fabricate such ma-terials with nanostructure as well as amorphous structure is still full of challenges.In this work,high-entropy metal organic framework(HE-MOF)is employed as the self-sacrificial template to fabricate FeCoNiCuMnP x high-entropy phosphide/carbon(HEP/C)composites.The obtained composite shows a het-erostructured fusiform morphology,in which the HEP is encapsulated by a carbon layer,revealing high electron conductivity as well as rich catalytic active sites for oxygen evolution reaction(OER).Beside,it is found that there is a short-range ordered crystal structure in the amorphous phase,which is bene-ficial for revealing high OER catalytic activity as well as good stability.As a result,the optimum HEP/C composite shows an overpotential 239 mV@10 mA cm^(−2)with a small Tafel slope of 72.5 mV dec^(−1) for catalyzing OER in alkaline solution.展开更多
Development of catholytes with long-cycle lifespan,high interfacial stability,and fast electrochemical kinetics is crucial for the comprehensive deployment of high-energy density lithium metal batteries(LMBs)with cost...Development of catholytes with long-cycle lifespan,high interfacial stability,and fast electrochemical kinetics is crucial for the comprehensive deployment of high-energy density lithium metal batteries(LMBs)with cost-efficiency.In this study,a lithiated 2-mercaptopyridine(2-MP-Li)organosulfide was synthesized and used as the soluble catholyte for the first time.Under the routine working mode,the LMB using this 2-MP-Li catholyte possessed high capacity retention of 55.4%with a Coulombic efficiency(CE)of near 100%after 2,000 cycles.When a cell system was fully filled with 2-MP-Li catholyte,it yielded a double capacity with 15%improvement in the capacity retention,corresponding to 0.0182%capacity decay per cycle,as well as excellent rate performance even at 6 mA·cm^(−2).These superior achievements resulted from the enhanced interfacial stability of Li anode induced by the salt-type 2-MP-Li molecule and the avoiding of using neutral catholyte as the initial active material,thereby mitigating the side reactions originating from the polysulfide shuttle effect.Furthermore,density functional theory(DFT)calculation and kinetics investigations proved the pseudocapacitive characteristic and faster ion diffusion coefficient with this design.Besides,the fabricated energy storage device showed excellent performance but with low economic cost and easy processing.Such a LMB with an alterable amount of capacity has a high potential to be applied in flow-cell type batteries for large-scale grid energy storage in the future.展开更多
Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seaw...Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seawater,the chlorine evolution reaction always competes with the oxygen evolution reaction(OER)at the anode,and chloride corrosion occurs on both the anode and cathode.Thus,effective electrocatalysts with high selectivity toward the OER and excellent resistance to chloride corrosion should be developed.In this critical review,we focus on the prospects of state-of-the-art metal-oxide electrocatalysts,including noble metal oxides,non-noble metal oxides and their compounds,and spinel-and perovskite-type oxides,for seawater splitting.We elucidate their chemical properties,excellent OER selectivity,outstanding anti-chlorine-corrosion performance,and reaction mechanisms.In particular,we review metal oxides that operate at high current densities,near industrial application levels,based on special catalyst design strategies.展开更多
Earth-abundant seawater resource has become an attractive candidate to produce hydrogen from electrolysis,which is of great significance to realize hydrogen economy and carbon neutrality.Nonetheless,developing highly ...Earth-abundant seawater resource has become an attractive candidate to produce hydrogen from electrolysis,which is of great significance to realize hydrogen economy and carbon neutrality.Nonetheless,developing highly active and stable electrocatalysts to meet the needs of highly effective seawater splitting is still challenging for the sluggish oxygen evolution dynamics and the existed competitive reaction of chlorine evolution reaction(CER).To this end,some newly-developed electrocatalysts with superior performance,such as noble metals,alloy,transition metals,oxides,carbides,nitrides,phosphides,and so on,have been synthesized for the seawater splitting in recent years.This review starts from the historical background and fundamental mechanisms,and summarizes the most recent progress in the development of seawater electrolysis technologies.Some existing issues in the process of seawater electrolysis are enumerated and the corresponded solutions are presented.The future of hydrogen production from seawater electrolysis,especially the design and synthesis of novel catalysts for seawater electrolysis,is prospected.展开更多
As a new type of green solvent with non-volatility,high thermal stability,high conductivity and various adjustable properties,ionic liquid(IL)has been widely used in the capture and electrochemical reduction of carbon...As a new type of green solvent with non-volatility,high thermal stability,high conductivity and various adjustable properties,ionic liquid(IL)has been widely used in the capture and electrochemical reduction of carbon dioxide(CO_(2)).To date,many studies have been made to investigate CO_(2)capture by using different types of ILs and CO_(2)electrochemical reduction(CO_(2)ER)with ILs as either electrolyte or other catalytic active components.Some structure-activity relationships between the structure and adsorption or catalytic properties of ILs have been found.Herein,the absorption performances and mechanisms of conventional ILs,amino-functionalized ILs,non-amino functionalized ILs and supported ILs for CO_(2)capture,as well as the performances and action mechanisms of ILs as the electrolyte,electrolyte additive,and/or electrode modifier in the process of CO_(2)ER are summarized.Many researches indicate that the unique interaction between the anion or cation of IL and CO_(2)has a significant contribution to promote the absorption and conversion of CO_(2).However,the ILs used for CO_(2)capture and electrochemical reduction should be further explored.Especially,a more in-depth investigation of the adsorption and catalytic mechanisms with the help of quantum chemical calculation,molecular simulation,and in situ characterization techniques is necessary.It is expected to design and develop more efficient ILs used for CO_(2)capture and conversion on a large scale.展开更多
Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date...Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date,HEMs have been a new family of advanced electrocatalysts in the research field of water electrolysis.In this work,the structural features and synthesis strategies of high entropy catalysts are reviewed,especially,their performances for catalyzing hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in water electrolysis are presented,in which the crucial roles of structure,composition,multisites synergy,and“four core effects”for enhancing catalytic activity,stability,and resistance of electrochemical corrosion are introduced.Besides,the design tactics,main challenges,and future prospects of HEM-based electrocatalysts for HER and OER are discussed.It is expected to provide valuable information for the development of low-cost efficient HEM-based electrocatalysts in the field of water electrolysis.展开更多
Designing and fabricating of heterostructured materials with long-term cycling stability and high-rate capacity for the anode of sodium-ion batteries(SIBs)still remain a great challenge.Herein,micro-flower-like MoS_(2...Designing and fabricating of heterostructured materials with long-term cycling stability and high-rate capacity for the anode of sodium-ion batteries(SIBs)still remain a great challenge.Herein,micro-flower-like MoS_(2)-modified Co_(9)S_(8)(Co_(9)S_(8)/MoS_(2))with a three-dimensional(3D)heterostructure was first obtained via a simple solvothermal synthesis followed by a solid sulfidation treatment process.As a material for the anode of SIBs,the Co_(9)S_(8)/MoS_(2)-based electrode with an initial Co/Mo molar ratio of 1/1(denoted as CM55-S)exhibits the best sodium storage performance with a boosted capacity,superior reversibility(424.5 mAh g^(-1)@2 A g^(-1)at the 1600th cycle,401.1 mAh g^(-1)@5 A g^(-1)at the 800th cycle),and an excellent rate capacity(210.1 mAh g^(-1)@20 A g^(-1)).Density functional theory(DFT)calculations confirm that the Co_(9)S_(8)/MoS_(2)heterostructure has a lower energy barrier(0.30 eV)than the pure Co_(9)S_(8)(0.53 eV).It is expected that such a heterostructured material could be an attractive candidate as the material of the anode for SIBs.展开更多
In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results...In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results showed that the gasification rate of BC was highly enhanced after mixing it with BP and the obvious synergistic effect was observed in all investigated three mixing weight ratios(i.e.,1:1,1:4,4:1),resulting in a higher carbon conversion as well as a H_(2)-rich gas production yield for the co-gasification.However,the extent of promotion by synergistic effect was affected by the reaction temperature,mixing ratio,and steam amount.It was found that the high potassium(K)species content in the BP provided the catalytic effect not only on water-gas shift reaction but also on tar reforming/cracking,thereby enhancing the gasification of BC.In addition,it is confirmed that steam should be an important factor to promote the synergistic effect and H_(2)-rich gas production.展开更多
Mn-Co mixed oxides were electrodeposited on Cu nanowires generated on Cu foam(CF)and used for effectively catalytic oxidation of toluene.The physical and chemical properties of the prepared catalysts were characterize...Mn-Co mixed oxides were electrodeposited on Cu nanowires generated on Cu foam(CF)and used for effectively catalytic oxidation of toluene.The physical and chemical properties of the prepared catalysts were characterized by SEM,TEM,XRD,H_(2)-TPR,O_(2)-TPD and XPS.It is found that the Mn-Co mixed metal oxides were uniformly coated on the Cu nanowires by the electrochemical method,whose Mn/Co ratio can be tuned by adjusting the molar ratio of Mn/Co in the initial solution for the electrodeposition.The intimate contact between Mn and Co nanocrystals was found by HRTEM,which is important for realizing synergetic effects on improving catalytic activity.Meanwhile,the formation of the active surface oxygen species and the increase of the active species of Mn^(4+)and Co^(3+)were considered to make significant contribution to the catalytic oxidation of toluene.Mn-Co mixed metal oxide catalysts exhibited higher performance than the single metal oxide,and especially 0.10Mn-0.01Co/CF catalyst with the Mn/Co molar ratio of 10:1 in the initial solution for the electrodeposition achieved the highest catalytic activity with a low toluene conversion temperature(T_(90%))of 251℃,and displayed excellent catalytic stability even in the presence of water vapor.It is expected that such a simply-electrodeposited mixed metal oxides based catalysts could be applied for the oxidation of volatile organic compounds(VOCs)in a practical process.展开更多
A series of hetero-metal(Ni,Mn,and Cu)doped Co-based catalysts were prepared by a unipolar pulse electro-deposition(UPED)method and applied for the catalytic combustion of toluene.It is found that hetero-metal doping ...A series of hetero-metal(Ni,Mn,and Cu)doped Co-based catalysts were prepared by a unipolar pulse electro-deposition(UPED)method and applied for the catalytic combustion of toluene.It is found that hetero-metal doping significantly influenced the morphology and surface elemental compositions of Co-based catalysts,and the increase in the contents of Ni and Mn elements made a negative influence on the catalyst structure.H_(2)-TPR and O_(2)-TPD analysis results suggested that the hetero-metal doping enhanced the low temperature reducibility and resulted in the formation of lattice defects,which were favorable to generate more easily reducible species and facilitate the oxygen mobility,thereby improved the performance for the catalytic combustion of toluene.Especially,the Co-Cu/NF catalyst performed the best catalytic activity with the lowest toluene conversion temperature of T90 at 248℃,which should be contributed by its low-temperature reducibility,increased surface and lattice oxygen species,and high content of active Co^(3+)species promoted by the interaction of the mixed metal oxides.Moreover,the Co-Cu/NF also performed excellent catalytic stability and high selectivity to CO_(2) in the presence and absence of water vapor for the catalytic combustion of toluene for a long term.展开更多
Catalytic coal gasification for methane production is a promising technology in the clean coal utilization field.In this review,the technologies for coal-derived natural gas production,the catalytic coal gasification ...Catalytic coal gasification for methane production is a promising technology in the clean coal utilization field.In this review,the technologies for coal-derived natural gas production,the catalytic coal gasification processes and the used reactors were compared.The compared catalysts mainly included single-component,composite,and disposable catalysts.The effects of catalyst properties included composition,preparation method,supporter and loading amount were further illustrated.The influences of coal properties included char preparation method,particle size,and ash content on catalytic performance were investigated.The effects of temperatures and pressures on gasification performance were discussed in details.The evaporation,melting,decomposition,and inactivation of catalyst under various temperatures and pressures were also analyzed.It is expected to provide comprehensive information on the researches of catalytic coal gasification for methane production.展开更多
Construction of photocatalysts with a Schottky heterojunction could realize highly efficient and stable degradation of organic pollutes in the wastewater.In this work,a precipitation method was used to prepare Ti_(3)C...Construction of photocatalysts with a Schottky heterojunction could realize highly efficient and stable degradation of organic pollutes in the wastewater.In this work,a precipitation method was used to prepare Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite photocatalysts with the Schottky heterojunction for the decomposition of tetracycline(TC)antibiotics under visible light.As-prepared photocatalysts were characterized by various techniques such as X-ray diffraction analysis(XRD),High resolution transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).When the best Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite was applied for the degradation of TC under visible light,the degradation efficiency reached up to 97.6%only in 50 min.It is considered that superoxide radical(O_(2)^(→))and hole(h^(+))were the main reactive species for the TC degradation,and in the Schottky heterojunction,e^(-)-h^(+)pairs in the catalyst could be transferred and separated effectively,resulting in obviously enhanced photocatalytic efficiency and stability.展开更多
Electrolyte formulation with high stability towards both Li metal anode and high-voltage cathode is considered as one of key points for the high-energy density lithium metal batteries(LMBs).In our previous study,by ad...Electrolyte formulation with high stability towards both Li metal anode and high-voltage cathode is considered as one of key points for the high-energy density lithium metal batteries(LMBs).In our previous study,by adding only 2%of 2-fluoropyridine(2-FP)as the additive in the carbonate and ether-based electrolyte formulations effectively suppressed Li dendrite growth.In this study,we further found that the main fluoropyridine(FP)family members can serve as not only the effective additive but also the excellent electrolyte solvent in the electrolyte formulations to enhance the performance of LMBs.For the 2-FP,when it was also used the electrolyte solvent and paired with single-salt lithium bis(trifluoromethylsulfonyl)imide(Li TFSI),the obtained electrolyte formulation of 1 M Li TFSI in pure2-FP solvent not only allowed faster ion transport though solvation effect,but also possessed impressive oxidation stability window over 4.3 V.As a result,the high-voltage LiNi_(1/3)Mn1_(/3)Co_(1/3)O_(2)(1.5 mA h cm^(-2))|Li metal battery with it exhibited a capacity retention of more than 80%over a long-term cycle even at 0.45 m A cm^(-2)with a lean electrolyte(30μL).Meanwhile,for another FP family member(i.e.,3-FP)as the electrolyte additive,the 4.3 V LMBs with the carbonate-based electrolyte containing only 1%of 3-FP maintained 83.9%of initial capacity after 200 cycles at 0.75 m A cm^(-2).Density functional theory(DFT)calculations and experiments confirmed that three typical FPs,i.e.,2-FP,3-FP and 4-FP can not only regulate the initial Li nucleation process,but more importantly also induce a protective layer,leading to a uniform and dendrites-free Li deposition.This bifunction of the FP family member as either electrolyte solvent or additive in the electrolyte formulations should be promising for the achieving of dendrites-free high-energy density LMBs.展开更多
Currently,CO_(2) conversion and utilization have become a key to mitigate the global warming.In this study,a novel separate-type autothermal dry reforming of methane(S-ATDRM)system is proposed and simulated,in which t...Currently,CO_(2) conversion and utilization have become a key to mitigate the global warming.In this study,a novel separate-type autothermal dry reforming of methane(S-ATDRM)system is proposed and simulated,in which the methane dry reforming combined with methane partial oxidation is performed in a circulating fluidized bed with exergy recuperation to eliminate the negative effect of the products of CH_(4) partial oxidation on the DRM reaction and further improve the CO_(2) conversion efficiency.The results demonstrate that this S-ATDRM system can achieve an exergy efficiency of 84.7%,and about 1055.7 kW of exergy can be recuperated from the process for crude syngas cooling and reapplied for pre-heating of feedstocks of CO_(2),O2 and CH_(4).It is found that the largest exergy destruction in this system occurs in the partial oxidation reactor,which occupies ca.45.6%of the whole exergy loss.Comparing with the conventional ATDRM system,although the exergy of S-ATDRM system is decreased by approximately 0.3%,the CO_(2) conversion is substantially increased by about 11.3%.展开更多
Introduction of vacancies is a promising route to enhance the performance of electrocatalysts by tuning the electronic structure and bonding energy.Here,the influence of ultrasound treatment on the O vacancies formati...Introduction of vacancies is a promising route to enhance the performance of electrocatalysts by tuning the electronic structure and bonding energy.Here,the influence of ultrasound treatment on the O vacancies formation and interlayer spacing in NiFe layered double hydroxide(LDH)was investigated.It is found that the strong ultrasound treatment results in rich O vacancies on the surface of NiFe LDH,which affect the electrocatalysis performance.Besides,the ultrasound treated NiFe LDH electrocatalysts had a reduced thickness with a hexagonal nanosheet morphology and expanded interlayer distance,which could promote the diffusion of reactant and generated gas.When the obtained defect-rich NiFe LDH electrocatalyst prepared by a 10-min ultrasonic treatment was applied to catalyze oxygen evolution reaction(OER),only 194 mV of overpotential was needed to maintain a current density of 10 mA⋅cm^(-2).展开更多
基金sponsored by the National Natural Science Foundation of China (21506139 and U1710101)。
文摘For a cyclone, it is possible to improve separation efficiency and reduce pressure drop by increasing the cyclone height. However, an exceeded height increase could result in a dramatical drop in separation efficiency. In this study, experimental and computational fluid dynamics simulation results exhibit that the introduction of an apex cone at the dust outlet could avoid the risk of separation efficiency drop but lead to a continuous reducing of the pressure drop. Generally, the optimal cyclone height should be closely related to the natural vortex length. While, when the vortex end contracts into the separation space in the cyclone with an exceeded height, severe back-mixing of particles always occurs, which will result in the decrease of separation efficiency. Herein, it is found that when an apex cone is installed at the dust outlet, the vortex end can be grasped by the cone so as to weaken the back-mixing of particles.Meanwhile, the introduction of this apex cone can enhance the secondary separation to capture the back-mixed particles again so as to protect the efficiency. In addition, it is found that the enhanced secondary separation could come from either the stagnant current of axial velocity in the center or the improved tangential velocity of inner vortex whereas the forcibly extending the length of vortex to exceed its natural length will not significantly increase efficiency.
基金The financial supports from the Natural Science Foundation of Henan Province(NO.202300410433)the Scientific Research Foundation of Zhengzhou University(2021cxcy566)are greatly appreciated.
文摘Soybean can serve as an efficient carbon and nitrogen source for in-situ fabrication of efficient composite electrocatalysts with conductive nitrogen-doped carbon(N-C)material.In this study,the iron-doped cobalt nitride/phosphide(Fe-Co_(3)N/CoP)nanosheet was composited with a conductive N-C material by using soybean as C and N source,as well as NH3 as additional nitrogen source.During the nitridation process of Fe-Co_(3)N,N-C bond was formed as a newly generated Co(Fe)-N-C active sites.Therefore,it fabricates a good microscopic contact interface between the catalyst and carbon material for charge transfer.Besides,the introduction of Fe-CoP by partially phosphating Fe-Co_(3)N further improved the OER activity due to the high catalytic activity of Co sites with high valence state.As a result,the obtained electrocatalyst exhibited overpotentials as low as 285 and 390 mV for supporting 10 and 100 mA/cm2 current densities.This work indicates that the design of materials with good interfaces could be an effective approach for the preparation of electrocatalysts for water electrolysis.
基金support by the National Natural Science Foundation of China(21975173 and 21776195)the fund for Shanxi“1331 project”and Major Projects of Shanxi Province(201803D121043).
文摘Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield as well as low selectivity.Herein,effective increase of higher alcohols proportion in the product is realized by direct conversion of syngas over electronically-modulated ZnO semiconductor via Cu doping.It is considered that the lower Fermi level and narrower band gap of catalysts by embedding Cu^(2+)into ZnO lattice could facilitate donor reaction by boosting the process for the reactants to obtain electrons on the catalyst surface for the formation of CH_(x) species and carbon chain growth,in which the Cu doping on ZnO lattice play important role in the promotion of CO adsorption.As a result,4 mol%Cu doped ZnO exhibits a highest C_(2+) OH/ROH fraction of 48.1%.Selectivity of catalysts from straight chain alcohol is better than from branch chain alcohol,which is different from promoted Cu/ZnO based catalyst.However,over-doping of Cu(7 mol%)on ZnO results in the aggregation Cu species on ZnO surface,leading to a sharp decrease of higher alcohols proportion to 3.2%.The results shed light on the nature that a direct correlation between semiconductor Fermi level and synthesis of higher alcohols,and the semiconductor-based catalysts mainly accelerate the hydrogenation reactions by enhancing thermally excited electron transfer.
基金supported by the Natural Science Foundation of Henan Province(No.202300410433)the College Students’Innovative Entrepreneurial Training(No.2022cxcy029),ChinaHirosaki University,Japan,are appreciated.
文摘Amorphous high-entropy materials with abundant defects,coordinatively unsaturated sites,and loosely bonded atoms could exhibit excellent electrocatalytic performance.However,how to fabricate such ma-terials with nanostructure as well as amorphous structure is still full of challenges.In this work,high-entropy metal organic framework(HE-MOF)is employed as the self-sacrificial template to fabricate FeCoNiCuMnP x high-entropy phosphide/carbon(HEP/C)composites.The obtained composite shows a het-erostructured fusiform morphology,in which the HEP is encapsulated by a carbon layer,revealing high electron conductivity as well as rich catalytic active sites for oxygen evolution reaction(OER).Beside,it is found that there is a short-range ordered crystal structure in the amorphous phase,which is bene-ficial for revealing high OER catalytic activity as well as good stability.As a result,the optimum HEP/C composite shows an overpotential 239 mV@10 mA cm^(−2)with a small Tafel slope of 72.5 mV dec^(−1) for catalyzing OER in alkaline solution.
基金supported by the ZiQoo Chemical Co.,Ltd.All authors greatly acknowledge Associate Professor Akihiro Yoshida at Hirosaki University,Japan,to help measuring 1H NMR spectrum.Z.K.X.greatly acknowledges the Key Scientific Research Project of Universities in Henan Province(No.22A150023)Zhengzhou University Young Teacher Special Fund(No.226-33212552).
文摘Development of catholytes with long-cycle lifespan,high interfacial stability,and fast electrochemical kinetics is crucial for the comprehensive deployment of high-energy density lithium metal batteries(LMBs)with cost-efficiency.In this study,a lithiated 2-mercaptopyridine(2-MP-Li)organosulfide was synthesized and used as the soluble catholyte for the first time.Under the routine working mode,the LMB using this 2-MP-Li catholyte possessed high capacity retention of 55.4%with a Coulombic efficiency(CE)of near 100%after 2,000 cycles.When a cell system was fully filled with 2-MP-Li catholyte,it yielded a double capacity with 15%improvement in the capacity retention,corresponding to 0.0182%capacity decay per cycle,as well as excellent rate performance even at 6 mA·cm^(−2).These superior achievements resulted from the enhanced interfacial stability of Li anode induced by the salt-type 2-MP-Li molecule and the avoiding of using neutral catholyte as the initial active material,thereby mitigating the side reactions originating from the polysulfide shuttle effect.Furthermore,density functional theory(DFT)calculation and kinetics investigations proved the pseudocapacitive characteristic and faster ion diffusion coefficient with this design.Besides,the fabricated energy storage device showed excellent performance but with low economic cost and easy processing.Such a LMB with an alterable amount of capacity has a high potential to be applied in flow-cell type batteries for large-scale grid energy storage in the future.
基金This work is supported by ZiQoo Chemical Co.Ltd.,Japan,and Hydrogen Energy Systems Society of Japan.Chen and Feng gratefully acknowledge the State Scholarship Fund of China Scholarship Council,China.Kitiphatpiboon gratefully acknowledges MEXT of Japan for the scholarship,Japan.
文摘Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seawater,the chlorine evolution reaction always competes with the oxygen evolution reaction(OER)at the anode,and chloride corrosion occurs on both the anode and cathode.Thus,effective electrocatalysts with high selectivity toward the OER and excellent resistance to chloride corrosion should be developed.In this critical review,we focus on the prospects of state-of-the-art metal-oxide electrocatalysts,including noble metal oxides,non-noble metal oxides and their compounds,and spinel-and perovskite-type oxides,for seawater splitting.We elucidate their chemical properties,excellent OER selectivity,outstanding anti-chlorine-corrosion performance,and reaction mechanisms.In particular,we review metal oxides that operate at high current densities,near industrial application levels,based on special catalyst design strategies.
基金supported by ZiQoo Chemical Co.Ltd.,Japan,and Hydrogen Energy Systems Society of Japan.Feng and Chen gratefully acknowledge the State Scholarship Fund of China Scholarship Council,China.
文摘Earth-abundant seawater resource has become an attractive candidate to produce hydrogen from electrolysis,which is of great significance to realize hydrogen economy and carbon neutrality.Nonetheless,developing highly active and stable electrocatalysts to meet the needs of highly effective seawater splitting is still challenging for the sluggish oxygen evolution dynamics and the existed competitive reaction of chlorine evolution reaction(CER).To this end,some newly-developed electrocatalysts with superior performance,such as noble metals,alloy,transition metals,oxides,carbides,nitrides,phosphides,and so on,have been synthesized for the seawater splitting in recent years.This review starts from the historical background and fundamental mechanisms,and summarizes the most recent progress in the development of seawater electrolysis technologies.Some existing issues in the process of seawater electrolysis are enumerated and the corresponded solutions are presented.The future of hydrogen production from seawater electrolysis,especially the design and synthesis of novel catalysts for seawater electrolysis,is prospected.
基金supported by JSPS KAKENHI Grant 22H01855,Japan,Natural Science Foundation of Shanxi Province(No.202103021223044)China,and Shanxi Scholarship Council of China(2022-078),China.
文摘As a new type of green solvent with non-volatility,high thermal stability,high conductivity and various adjustable properties,ionic liquid(IL)has been widely used in the capture and electrochemical reduction of carbon dioxide(CO_(2)).To date,many studies have been made to investigate CO_(2)capture by using different types of ILs and CO_(2)electrochemical reduction(CO_(2)ER)with ILs as either electrolyte or other catalytic active components.Some structure-activity relationships between the structure and adsorption or catalytic properties of ILs have been found.Herein,the absorption performances and mechanisms of conventional ILs,amino-functionalized ILs,non-amino functionalized ILs and supported ILs for CO_(2)capture,as well as the performances and action mechanisms of ILs as the electrolyte,electrolyte additive,and/or electrode modifier in the process of CO_(2)ER are summarized.Many researches indicate that the unique interaction between the anion or cation of IL and CO_(2)has a significant contribution to promote the absorption and conversion of CO_(2).However,the ILs used for CO_(2)capture and electrochemical reduction should be further explored.Especially,a more in-depth investigation of the adsorption and catalytic mechanisms with the help of quantum chemical calculation,molecular simulation,and in situ characterization techniques is necessary.It is expected to design and develop more efficient ILs used for CO_(2)capture and conversion on a large scale.
基金supported by Natural Science Foundation of Henan Province(NO.202300410433)ZiQoo Chemical Co.Ltd,Japan.We also appreciate Mr Lijie Hou of the Shiyanjia Lab(www.shiyanjia.com)for providing the supporting materials.
文摘Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date,HEMs have been a new family of advanced electrocatalysts in the research field of water electrolysis.In this work,the structural features and synthesis strategies of high entropy catalysts are reviewed,especially,their performances for catalyzing hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in water electrolysis are presented,in which the crucial roles of structure,composition,multisites synergy,and“four core effects”for enhancing catalytic activity,stability,and resistance of electrochemical corrosion are introduced.Besides,the design tactics,main challenges,and future prospects of HEM-based electrocatalysts for HER and OER are discussed.It is expected to provide valuable information for the development of low-cost efficient HEM-based electrocatalysts in the field of water electrolysis.
基金supported by ZiQoo Chemical Co.Ltd.,Japan.C.Liu gratefully acknowledges China Scholarship Council(CSC),China.
文摘Designing and fabricating of heterostructured materials with long-term cycling stability and high-rate capacity for the anode of sodium-ion batteries(SIBs)still remain a great challenge.Herein,micro-flower-like MoS_(2)-modified Co_(9)S_(8)(Co_(9)S_(8)/MoS_(2))with a three-dimensional(3D)heterostructure was first obtained via a simple solvothermal synthesis followed by a solid sulfidation treatment process.As a material for the anode of SIBs,the Co_(9)S_(8)/MoS_(2)-based electrode with an initial Co/Mo molar ratio of 1/1(denoted as CM55-S)exhibits the best sodium storage performance with a boosted capacity,superior reversibility(424.5 mAh g^(-1)@2 A g^(-1)at the 1600th cycle,401.1 mAh g^(-1)@5 A g^(-1)at the 800th cycle),and an excellent rate capacity(210.1 mAh g^(-1)@20 A g^(-1)).Density functional theory(DFT)calculations confirm that the Co_(9)S_(8)/MoS_(2)heterostructure has a lower energy barrier(0.30 eV)than the pure Co_(9)S_(8)(0.53 eV).It is expected that such a heterostructured material could be an attractive candidate as the material of the anode for SIBs.
基金supported by JST Grant Number JPMJPF2104 and Hirosaki University Fundthe scholarship from the Ministry of Education,Culture,Sport,Science and Technology(MEXT)of Japan.
文摘In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results showed that the gasification rate of BC was highly enhanced after mixing it with BP and the obvious synergistic effect was observed in all investigated three mixing weight ratios(i.e.,1:1,1:4,4:1),resulting in a higher carbon conversion as well as a H_(2)-rich gas production yield for the co-gasification.However,the extent of promotion by synergistic effect was affected by the reaction temperature,mixing ratio,and steam amount.It was found that the high potassium(K)species content in the BP provided the catalytic effect not only on water-gas shift reaction but also on tar reforming/cracking,thereby enhancing the gasification of BC.In addition,it is confirmed that steam should be an important factor to promote the synergistic effect and H_(2)-rich gas production.
文摘Mn-Co mixed oxides were electrodeposited on Cu nanowires generated on Cu foam(CF)and used for effectively catalytic oxidation of toluene.The physical and chemical properties of the prepared catalysts were characterized by SEM,TEM,XRD,H_(2)-TPR,O_(2)-TPD and XPS.It is found that the Mn-Co mixed metal oxides were uniformly coated on the Cu nanowires by the electrochemical method,whose Mn/Co ratio can be tuned by adjusting the molar ratio of Mn/Co in the initial solution for the electrodeposition.The intimate contact between Mn and Co nanocrystals was found by HRTEM,which is important for realizing synergetic effects on improving catalytic activity.Meanwhile,the formation of the active surface oxygen species and the increase of the active species of Mn^(4+)and Co^(3+)were considered to make significant contribution to the catalytic oxidation of toluene.Mn-Co mixed metal oxide catalysts exhibited higher performance than the single metal oxide,and especially 0.10Mn-0.01Co/CF catalyst with the Mn/Co molar ratio of 10:1 in the initial solution for the electrodeposition achieved the highest catalytic activity with a low toluene conversion temperature(T_(90%))of 251℃,and displayed excellent catalytic stability even in the presence of water vapor.It is expected that such a simply-electrodeposited mixed metal oxides based catalysts could be applied for the oxidation of volatile organic compounds(VOCs)in a practical process.
文摘A series of hetero-metal(Ni,Mn,and Cu)doped Co-based catalysts were prepared by a unipolar pulse electro-deposition(UPED)method and applied for the catalytic combustion of toluene.It is found that hetero-metal doping significantly influenced the morphology and surface elemental compositions of Co-based catalysts,and the increase in the contents of Ni and Mn elements made a negative influence on the catalyst structure.H_(2)-TPR and O_(2)-TPD analysis results suggested that the hetero-metal doping enhanced the low temperature reducibility and resulted in the formation of lattice defects,which were favorable to generate more easily reducible species and facilitate the oxygen mobility,thereby improved the performance for the catalytic combustion of toluene.Especially,the Co-Cu/NF catalyst performed the best catalytic activity with the lowest toluene conversion temperature of T90 at 248℃,which should be contributed by its low-temperature reducibility,increased surface and lattice oxygen species,and high content of active Co^(3+)species promoted by the interaction of the mixed metal oxides.Moreover,the Co-Cu/NF also performed excellent catalytic stability and high selectivity to CO_(2) in the presence and absence of water vapor for the catalytic combustion of toluene for a long term.
基金financially supported by Shangrao Natural Science Foundation(No.2020L001)Natural Science Foundation of China(No.51976226)Science Foundation of North University of China(No.XJJ201923).
文摘Catalytic coal gasification for methane production is a promising technology in the clean coal utilization field.In this review,the technologies for coal-derived natural gas production,the catalytic coal gasification processes and the used reactors were compared.The compared catalysts mainly included single-component,composite,and disposable catalysts.The effects of catalyst properties included composition,preparation method,supporter and loading amount were further illustrated.The influences of coal properties included char preparation method,particle size,and ash content on catalytic performance were investigated.The effects of temperatures and pressures on gasification performance were discussed in details.The evaporation,melting,decomposition,and inactivation of catalyst under various temperatures and pressures were also analyzed.It is expected to provide comprehensive information on the researches of catalytic coal gasification for methane production.
基金supported by the Natural Science Foundation of Shanxi Province,China(201901D111308)Hirosaki University Fund.
文摘Construction of photocatalysts with a Schottky heterojunction could realize highly efficient and stable degradation of organic pollutes in the wastewater.In this work,a precipitation method was used to prepare Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite photocatalysts with the Schottky heterojunction for the decomposition of tetracycline(TC)antibiotics under visible light.As-prepared photocatalysts were characterized by various techniques such as X-ray diffraction analysis(XRD),High resolution transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).When the best Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite was applied for the degradation of TC under visible light,the degradation efficiency reached up to 97.6%only in 50 min.It is considered that superoxide radical(O_(2)^(→))and hole(h^(+))were the main reactive species for the TC degradation,and in the Schottky heterojunction,e^(-)-h^(+)pairs in the catalyst could be transferred and separated effectively,resulting in obviously enhanced photocatalytic efficiency and stability.
文摘Electrolyte formulation with high stability towards both Li metal anode and high-voltage cathode is considered as one of key points for the high-energy density lithium metal batteries(LMBs).In our previous study,by adding only 2%of 2-fluoropyridine(2-FP)as the additive in the carbonate and ether-based electrolyte formulations effectively suppressed Li dendrite growth.In this study,we further found that the main fluoropyridine(FP)family members can serve as not only the effective additive but also the excellent electrolyte solvent in the electrolyte formulations to enhance the performance of LMBs.For the 2-FP,when it was also used the electrolyte solvent and paired with single-salt lithium bis(trifluoromethylsulfonyl)imide(Li TFSI),the obtained electrolyte formulation of 1 M Li TFSI in pure2-FP solvent not only allowed faster ion transport though solvation effect,but also possessed impressive oxidation stability window over 4.3 V.As a result,the high-voltage LiNi_(1/3)Mn1_(/3)Co_(1/3)O_(2)(1.5 mA h cm^(-2))|Li metal battery with it exhibited a capacity retention of more than 80%over a long-term cycle even at 0.45 m A cm^(-2)with a lean electrolyte(30μL).Meanwhile,for another FP family member(i.e.,3-FP)as the electrolyte additive,the 4.3 V LMBs with the carbonate-based electrolyte containing only 1%of 3-FP maintained 83.9%of initial capacity after 200 cycles at 0.75 m A cm^(-2).Density functional theory(DFT)calculations and experiments confirmed that three typical FPs,i.e.,2-FP,3-FP and 4-FP can not only regulate the initial Li nucleation process,but more importantly also induce a protective layer,leading to a uniform and dendrites-free Li deposition.This bifunction of the FP family member as either electrolyte solvent or additive in the electrolyte formulations should be promising for the achieving of dendrites-free high-energy density LMBs.
基金JST Grant Number JPMJPF2104,Japan,and the National Natural Science Foundation of China(No.U1710101),P.R.China.Z.Zhao gratefully acknowledges China Scholarship Council(CSC)Y.Situmorang gratefully acknowledges the scholarship from Ministry of Education,Culture,Sport,Science and Technology(MEXT)of Japan.
文摘Currently,CO_(2) conversion and utilization have become a key to mitigate the global warming.In this study,a novel separate-type autothermal dry reforming of methane(S-ATDRM)system is proposed and simulated,in which the methane dry reforming combined with methane partial oxidation is performed in a circulating fluidized bed with exergy recuperation to eliminate the negative effect of the products of CH_(4) partial oxidation on the DRM reaction and further improve the CO_(2) conversion efficiency.The results demonstrate that this S-ATDRM system can achieve an exergy efficiency of 84.7%,and about 1055.7 kW of exergy can be recuperated from the process for crude syngas cooling and reapplied for pre-heating of feedstocks of CO_(2),O2 and CH_(4).It is found that the largest exergy destruction in this system occurs in the partial oxidation reactor,which occupies ca.45.6%of the whole exergy loss.Comparing with the conventional ATDRM system,although the exergy of S-ATDRM system is decreased by approximately 0.3%,the CO_(2) conversion is substantially increased by about 11.3%.
基金financial supports from the Natural Science Foundation of Henan Province(NO.202300410433)the Scientific Research Foundation of Zhengzhou University(32210862,32211241).
文摘Introduction of vacancies is a promising route to enhance the performance of electrocatalysts by tuning the electronic structure and bonding energy.Here,the influence of ultrasound treatment on the O vacancies formation and interlayer spacing in NiFe layered double hydroxide(LDH)was investigated.It is found that the strong ultrasound treatment results in rich O vacancies on the surface of NiFe LDH,which affect the electrocatalysis performance.Besides,the ultrasound treated NiFe LDH electrocatalysts had a reduced thickness with a hexagonal nanosheet morphology and expanded interlayer distance,which could promote the diffusion of reactant and generated gas.When the obtained defect-rich NiFe LDH electrocatalyst prepared by a 10-min ultrasonic treatment was applied to catalyze oxygen evolution reaction(OER),only 194 mV of overpotential was needed to maintain a current density of 10 mA⋅cm^(-2).
