A kind of new long life aluminum air batteries with open configuration was developed, using aluminum alloy doped with Ga, In, Sn, Bi, Pb and Mn as anode, NaCl solution as electrolyte and air electrode as cathode. The ...A kind of new long life aluminum air batteries with open configuration was developed, using aluminum alloy doped with Ga, In, Sn, Bi, Pb and Mn as anode, NaCl solution as electrolyte and air electrode as cathode. The polarization curves of aluminum electrode and air electrode were tested. And the cell′s performance was tested to calculate the utilization of aluminum electrode and the energy density. It is shown that, in the 3.5% NaCl solution, the cell can discharge at 0.29 A for 140 h with the working voltage keeping over 1.1 V. The utilization ratio of aluminum anode is over 44%, and the life of battery is longer than 2400 h.展开更多
X The catalysts of air electrode were prepared by sintering the active carbon loaded with manganese nitrate and potassium permanganate at 360 ℃ . The air electrode was made up of a catalyst layer, a waterproof and ga...X The catalysts of air electrode were prepared by sintering the active carbon loaded with manganese nitrate and potassium permanganate at 360 ℃ . The air electrode was made up of a catalyst layer, a waterproof and gas-permeable layer, a current collecting substrate and a second wa-terproof and gas-permeable layer. The cell was assembled by the air electrode, pure magnesium anode and 10% NaCl solution used as electrolyte. The microstructures of air electrodes before and after discharging were characterized by SEM. The electrochemical behaviors of the air electrodes were determined by means of polarization curves, volt-ampere curves and constant current discharge curves. The polarization voltage of air electrode is-173 mV （vs SCE） at the current density of 50 mA/cm2. The air electrodes exhibits good activity and stability in neutral electrolyte. The magnesium-air cell could work at 5 W for more than 7 h.展开更多
The electrochemical oxidation of 5-hydroxymethylfurfural(HMFOR)in alkaline electrolyte is a promising strategy for producing high-value chemicals from biomass derivatives.However,the disproportionation of aldehyde gro...The electrochemical oxidation of 5-hydroxymethylfurfural(HMFOR)in alkaline electrolyte is a promising strategy for producing high-value chemicals from biomass derivatives.However,the disproportionation of aldehyde groups under strong alkaline conditions and the polymerization of HMF to form humic substances can impact the purity of 2,5-furandicarboxylic acid(FDCA)products.The use of neutral electrolytes offers an alternative environment for electrolysis,but the lack of OH^(-)ions in the electrolyte often leads to low current density and low yields of FDCA.In this study,a sandwich-structured catalyst,consisting of Ru clusters confined between unilamellar MnO_(2)nanosheets(S-Ru/MnO_(2)),was used in conjunction with an electrochemical pulse method to realize the electrochemical conversion of5-hydroxymethylfurfural into FDCA in neutral electrolytes.Pulse electrolysis and the strong electron transfer between Ru clusters and MnO_(2)nanosheets help maintain Ru in a low oxidation state,ensuring high activity.The increased*OH generation led to a groundbreaking current density of 47 mA/cm^(2)at1.55 V vs.reversible hydrogen electrode(RHE)and an outstanding yield rate of 98.7%for FDCA in a neutral electrolyte.This work provides a strategy that combines electrocatalyst design with an electrolysis technique to achieve remarkable performance in neutral HMFOR.展开更多
To improve the atomic utilization of metals and reduce the cost of industrialization,the one-step total monoatomization of macroscopic bulk metals,as opposed to nanoscale metals,is effective.In this study,we used a th...To improve the atomic utilization of metals and reduce the cost of industrialization,the one-step total monoatomization of macroscopic bulk metals,as opposed to nanoscale metals,is effective.In this study,we used a thermal diffusion method to directly convert commercial centimeter-scale Ni foam to porous Ni single-atom-loaded carbon nanotubes(CNTs).As expected,owing to the coating of single-atom on porous,highly conductive CNT carriers,Ni single-atom electrocatalysts(Ni-SACs)exhibit extremely high activity and selectivity in CO_(2)electroreduction(CO_(2)RR),yielding a current density of>350 mA/cm^(2),a selectivity for CO of>91%under a flow cell configuration using a 1 M potassium chloride(KCl)electrolyte.Based on the superior activity of the Ni-SACs electrocatalyst,an integrated gas-phase electrochemical zero-gap reactor was introduced to generate a significant amount of CO current for potential practical applications.The overall current can be increased to 800 mA,while maintaining CO Faradaic efficiencies(FEs)at above 90%per unit cell.Our findings and insights on the active site transformation mechanism for macroscopic bulk Ni foam conversion into single atoms can inform the design of highly active single-atom catalysts used in industrial CO_(2)RR systems.展开更多
Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst onl...Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.展开更多
Developing stable and efficient nonprecious-metal-based oxygen evolution catalysts in the neutral electrolyte is a challenging but essential goal for various electrochemical systems.Particularly,cobalt-based spinels h...Developing stable and efficient nonprecious-metal-based oxygen evolution catalysts in the neutral electrolyte is a challenging but essential goal for various electrochemical systems.Particularly,cobalt-based spinels have drawn a considerable amount of attention but most of them operate in alkali solutions.However,the frequently studied Co-Fe spinel system never exhibits appreciable stability in nonbasic conditions,not to mention attract further investigation on its key structural motif and transition states for activity loss.Herein,we report exceptional stable Co-Fe spinel oxygen evolution catalysts(~30%Fe is optimal)in a neutral electrolyte,owing to its unique metal ion arrangements in the crystal lattice.The introduced iron content enters both the octahedral and tetrahedral sites of the spinel as Fe^(2+)and Fe^(3+)(with Co ions having mixed distribution as well).Combining density functional theory calculations,we find that the introduction of Fe to Co_(3)O_(4)lowers the covalency of metal-oxygen bonds and can help suppress the oxidation of Co^(2+/3+)and 0^(2-).It implies that the Co-Fe spinel will have minor surface reconstruction and less lattice oxygen loss during the oxygen evolution reaction process in comparison with Co_(3)O_(4)and hence show much better stability.These findings suggest that there is still much chance for the spinel structures,especially using reasonable sublattices engineering via multimetal doping to develop advanced oxygen evolution catalysts.展开更多
The V_2C compound,belonging to the group of two-dimensional transition metal carbonitrides,or MXenes,has demonstrated a promising electrochemical performance in capacitor applications in acidic electrolytes;however,th...The V_2C compound,belonging to the group of two-dimensional transition metal carbonitrides,or MXenes,has demonstrated a promising electrochemical performance in capacitor applications in acidic electrolytes;however,there is evidence to suggest that V_2C is unstable in an acidic environment.On the other hand,the performance of V_2C in neutral aqueous electrolytes is still moderate,and has not yet been systematically studied.The charge storage mechanism in a V_2C electrode,employed in neutral aqueous electrolytes,is investigated via cyclic voltammetry testing and in situ x-ray diffraction(XRD).Good specific capacitances are achieved,specifically208 F/g in 0.5 M Li_2SO_4,225 F/g in 1 M MgSO_4,120 F/g in 1 M Na_2 SO_4,and 104 F/g in 0.5 M K_2SO_4.Using in situ XRD,we observe that,during the charge and discharge process,the c-lattice parameter shrinks or expands by up to 0.25 A in MgSO_4,and 0.29 A in Li_2SO_4 which demonstrates the intercalation/de-intercalation of cations into the d-V_2C layer.展开更多
Inspired by the sophisticated artificial leather garment industry and toward enhancing wearability of energy storage devices, we demonstrate a polyurethane artificial leather supercapacitor with large sheet electrodes...Inspired by the sophisticated artificial leather garment industry and toward enhancing wearability of energy storage devices, we demonstrate a polyurethane artificial leather supercapacitor with large sheet electrodes embedded in theleather layer simultaneously working as a polyelectrolyte. This design totally reserves textiles underneath and thus addresses the well-known challenge of wearing comfortability. It provides a revolutionary configuration of wearable supercapacitors: the artificial leather on garment is also a supercapacitor.Unlike the polyvinyl alcohol-based acidic electrolytes, which are widely used, sodium chloride is used to modify the intrinsically fluorescent polyurethane leather for ionic transportation, which has no harm to human. The fluorescent leather supercapacitor is easily transferrable from any arbitrary substrates to form various patterns, enabling multifunctionalities of practical wearability, fashion, and energy storage.展开更多
Hydrogen evolution reaction(HER)in neutral medium suffers from slow kinetics as compared to that in alkaline or acidic conditions,owing to larger Ohmic loss and low proton concentration.Here we report that a self-supp...Hydrogen evolution reaction(HER)in neutral medium suffers from slow kinetics as compared to that in alkaline or acidic conditions,owing to larger Ohmic loss and low proton concentration.Here we report that a self-supported nanoporous Au-SnO_(x)(NP Au-SnO_(x))catalyst with gradient tin oxide surface could significantly enhance HER activity in neutral buffer solution(0.2 M PBS).The NP Au-SnO_(x)catalyst exhibits a low onset overpotential of 38 mV and a small Tafel slope of 79 mV dec^(−1).The current density of 10 mA cm^(−2)is manifested at an overpotential as low as 148 mV,representing the comparable performance of Pt/C catalyst.This high catalytic activity can retain at least 10 hours without any detectable decay.The superior HER activity is proposed to originate from the gradient SnO_(x)structure and metal/oxide interfaces in nanoporous ligaments.Furthermore,the X-ray photoelectron spectroscopy reveals that the gradient oxide in the ligament is remarkably stable during long-term reaction.展开更多
Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO_(2)reduction reaction(CO_(2)RR)toward multi-carbon(C2+)products,primarily by suppressing the pa...Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO_(2)reduction reaction(CO_(2)RR)toward multi-carbon(C2+)products,primarily by suppressing the parasitic hydrogen evolution reaction and facilitating a localized CO_(2)/CO concentration at the electrode.Building upon this approach,we developed surface-functionalized catalysts with exceptional activity and selectivity for electrocatalytic CO_(2)RR to C_(2+)in a neutral electrolyte.Employing CuO nanoparticles coated with hexaethynylbenzene organic molecules(HEB-CuO NPs),a remarkable C_(2+)Faradaic efficiency of nearly 90%was achieved at an unprecedented current density of 300 mA cm^(-2),and a high FE(>80%)was maintained at a wide range of current densities(100-600 mA cm^(-2))in neutral environments using a flow cell.Furthermore,in a membrane electrode assembly(MEA)electrolyzer,86.14%FEC2+was achieved at a partial current density of 387.6 mA cm^(-2)while maintaining continuous operation for over 50 h at a current density of 200 mA cm^(-2).In-situ spectroscopy studies and molecular dynamics simulations reveal that reducing the coverage of coordinated K⋅H2O water increased the probability of intermediate reactants(CO)interacting with the surface,thereby promoting efficient C-C coupling and enhancing the yield of C_(2+)products.This advancement offers significant potential for optimizing local micro-environments for sustainable and highly efficient C_(2+)production.展开更多
Electrocatalysis,which involves oxidation and reduction reactions with direct electron transfer,is essential for a variety of clean energy conversion devices.Currently,the vast majority of studies regarding electrocat...Electrocatalysis,which involves oxidation and reduction reactions with direct electron transfer,is essential for a variety of clean energy conversion devices.Currently,the vast majority of studies regarding electrocatalysis reactions focus on strong acidic or alkaline media because of the higher catalytic activity.Nevertheless,some inherent drawbacks,including the corrosive environment,expensive proton exchange membranes,and side effects,are still hard to break through.A sustainably promising way to overcome these shortcomings is to deploy neutral/near-neutral electrolytes for electrocatalysis reactions.Unfortunately,insufficient research in this area due to the lack of attention to related issues has slowed down the development process.In this review,we systematically review the catalytic reaction mechanisms,neutral electrolytes,electrocatalysts,and modification strategies carried out in neutral media on the three most common electrocatalytic reactions,that is,hydrogen evolution reaction,oxygen reduction reaction,and oxygen evolution reaction.Furthermore,the advanced characterization tools for guiding catalyst synthesis and mechanistic studies are also summarized.Eventually,we propose some challenges and perspectives on electrocatalysis reactions in neutral media and hope it will attract more research interest and provide guidance in neutral electrocatalysis.展开更多
Conductive metal-organic frameworks(c-MOFs)are promising active electrode materials for electrochemical double-layer capacitors with a performance that already exceeds most carbon-based materials.However,their excelle...Conductive metal-organic frameworks(c-MOFs)are promising active electrode materials for electrochemical double-layer capacitors with a performance that already exceeds most carbon-based materials.However,their excellent supercapacitance is primarily based on organic or alkaline electrolytes,which largely impede their broad applications and sustainabilities.In this work,we propose a new synthesis approach for fabricating carbon nanotubes and c-MOFs(CNT@MOFs)core–shell structures,which result in high supercapacitance in neutral aqueous electrolytes.We identify that CNTs provide abundant active sites to ensure high capacitance,and Ni3(2,3,6,7,10,11-hexaiminotriphenylene(HITP))2 nanoarrays that in situ grow on the surface of CNTs bundles can significantly improve the conductivity and provide enough ion transport pathways in aqueous electrolytes.Specifically,using CNT@MOFs core-shell structures as an electrode,we obtained a high initial capacitance of 150.7 F·g^(−1) at 0.1 A·g^(−1) in 1 M Na2SO4 solution and good capacity retention of 83.5%after 10,000 cycles at 4 A·g^(−1).We also found that the carboxyl groups on the surface of CNTs provide better anchor sites for the in situ growth of c-MOF,which promotes the uniform growth of c-MOF shells on the CNT surface and improves aqueous electrolyte accessibility.We believe that the high supercapacitance in aqueous electrolytes reported in this work would provide a good prospect for deploying c-MOF based energy storage devices into biomedical and other healthcare electronic applications.展开更多
Neutral Zn-air batteries(ZABs) have attracted much attention due to the enhanced lifespan and stability.However, their development is suppressed by the poor catalytic properties of the air-electrocatalysts for oxygen ...Neutral Zn-air batteries(ZABs) have attracted much attention due to the enhanced lifespan and stability.However, their development is suppressed by the poor catalytic properties of the air-electrocatalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER). Hence,the exploration of highly efficient electrocatalysts for neutral ZABs is critical. Herein, we designed an economical heterostructure of Pt nanoparticle-modified Zn nanoplates(Pt/Zn NPs). Compared with commercial Pt/C electrocatalyst, our Pt/Zn heterostructure exhibits comparable catalytic properties and ultrahigh stability in neutral media. The heterostructure can reduce the dosage of Pt and offer sufficient active sites,resulting in enhanced catalytic properties for ORR/OER in neutral media. When applied to neutral ZABs as air cathode,our heterostructure exhibits a high power density of 45 mW cm^(-2) and excellent stability of more than 850 cycles with negligible decay, making it the most efficient and robust one in neutral electrolyte. This approach opens a new avenue to strategically design catalysts with high activity for neutral ZABs, rendering them potential in portable and wearable electronic devices.展开更多
Developing efficient electrocatalysts for the oxygen evolution reaction(OER)under neutral conditions is important for microbial electrolysis cells(MECs).However,the OER kinetics in neutral electrolytes at present are ...Developing efficient electrocatalysts for the oxygen evolution reaction(OER)under neutral conditions is important for microbial electrolysis cells(MECs).However,the OER kinetics in neutral electrolytes at present are extremely sluggish,resulting in high overpotentials that greatly limit the energy conversion efficiencies of MECs.Previous studies failed to probe the adsorbates on surface metal sites of catalysts at the atomic scale and elucidate their influence on the catalytic activities,which has impeded the rational design of efficient neutral OER catalysts with optimal surface structures.Here,using in situ transmission electron microscopy(TEM),in situ X-ray photoelectron spectroscopy(XPS)and in situ low-energy ion scattering studies,we have identified,for the first time,that the electrochemically activated adsorbates on surface metal sites play a critical role in boosting the neutral OER activities of Ru-Ir binary oxide(RuxIryO2)catalysts.The adsorbate-activated RuxIryO2on a glassy carbon electrode achieved a low overpotential of 324 m V at10 m A cm-2in neutral electrolyte,with a 36-fold improvement in turnover frequency compared with that of Ir O2benchmark.Upon application in an MEC system,the resulting full cell showed a decreased voltage of 1.8 V,200 m V lower than the best value reported to date,facilitating efficient synthesis of poly(3-hydroxybutyrate)from bioelectrochemical CO2reduction.Density functional theory(DFT)studies revealed that the enhanced OER activity of RuxIryO2catalyst arose from local structural distortion of adjacent adsorbate-covered Ru octahedra at the catalyst surface and the consequently decreased adsorption energies of OER intermediates on Ir active center.展开更多
Electrocatalytic reduction of nitrate(NO_(3)^(−))and nitride(NO_(2)^(−))to ammonia(NH3)is of wide interest as a promising alternative to the energy-intensive Haber-Bosch route for mitigating the vast energy consumptio...Electrocatalytic reduction of nitrate(NO_(3)^(−))and nitride(NO_(2)^(−))to ammonia(NH3)is of wide interest as a promising alternative to the energy-intensive Haber-Bosch route for mitigating the vast energy consumption and the accompanied carbon dioxide emission,as well as benefiting for the relevant sewage treatment.However,exploring an efficient and low-cost catalyst with high atomic utilization that can effectively facilitate the slow multi-electron transfer process remains a grand challenge.Herein,we present an efficient hydrogenation of NO_(3)^(−)/NO_(2)^(−)species to NH3 in both alkaline and neutral environments over the Fe_(2)(MoO_(4))_(3)derived hybrid electrocatalyst with the metallic Fe site on FeMoO_(4)(Fe/FeMoO_(4)).The Mo ingredient can play a synergistically positive role in further promoting the NH_(3) production on Fe.As a result,Fe/FeMoO_(4)behaves well in the electrochemical NH_(3) generation from NO_(2)^(−)with a maximum NH_(3) Faradaic efficiency(FE)of 96.53%and 87.68%in alkaline and neutral electrolyte,corresponding to the NH_(3) yield rate of 640.68 and 302.56 mg·h^(−1)·mg_(cat.)^(−1),respectively,which outperforms the Fe and Mo counterpart and other similar catalyst,showing the robust catalytic capacity of each active site.展开更多
The primary objective in researching the anode side of electrochemical CO_(2) reduction reaction(CO_(2)RR)is to substitute the frequently employed Ir anodic catalyst with more readily available and cost-effective non-...The primary objective in researching the anode side of electrochemical CO_(2) reduction reaction(CO_(2)RR)is to substitute the frequently employed Ir anodic catalyst with more readily available and cost-effective non-noble metal oxide.When organic molecules are loaded on the Cu_(2)O surface,a synergistic effect can be formed between different components.This effect can accelerate electron transfer,provide new active sites,and further enhance the performance of reactants of oxygen evolutionreaction(OER).This study proposes a new type of anodic catalyst,PDI/Cu_(2)O/Cu,and investigates its OER activity and three other anodic catalysts(IrO_(2)/Ti mesh,Ni foam,and Pt mesh)in the CO_(2)RR system.The results show that PDI/Cu_(2)O/Cu exhibited OER activity with an overpotential of 422.1 mV to drive a current density of 70 mA·cm^(−2) in neutral electrolytes.Compared to IrO_(2)/Ti mesh,the overpotential of perylene tetracarboxylic di-(propyl imidazole)(PDI)/Cu_(2)O/Cu is decreased by 490 mV.This significantly lowers the energy consumption of the CO_(2)RR system without compromising the performance of CO_(2)RR.Furthermore,the use of precious metal materials is unnecessary,leading to a substantial reduction in the cost of the anodic catalyst.PDI/Cu_(2)O/Cu holds the potential to serve as a non-precious metal alternative to Ir in neutral electrolytes as an anodic catalyst.展开更多
基金This work was financially supported by the Doctor Foundation of Hebei Province (045472226D-1).
文摘A kind of new long life aluminum air batteries with open configuration was developed, using aluminum alloy doped with Ga, In, Sn, Bi, Pb and Mn as anode, NaCl solution as electrolyte and air electrode as cathode. The polarization curves of aluminum electrode and air electrode were tested. And the cell′s performance was tested to calculate the utilization of aluminum electrode and the energy density. It is shown that, in the 3.5% NaCl solution, the cell can discharge at 0.29 A for 140 h with the working voltage keeping over 1.1 V. The utilization ratio of aluminum anode is over 44%, and the life of battery is longer than 2400 h.
文摘X The catalysts of air electrode were prepared by sintering the active carbon loaded with manganese nitrate and potassium permanganate at 360 ℃ . The air electrode was made up of a catalyst layer, a waterproof and gas-permeable layer, a current collecting substrate and a second wa-terproof and gas-permeable layer. The cell was assembled by the air electrode, pure magnesium anode and 10% NaCl solution used as electrolyte. The microstructures of air electrodes before and after discharging were characterized by SEM. The electrochemical behaviors of the air electrodes were determined by means of polarization curves, volt-ampere curves and constant current discharge curves. The polarization voltage of air electrode is-173 mV （vs SCE） at the current density of 50 mA/cm2. The air electrodes exhibits good activity and stability in neutral electrolyte. The magnesium-air cell could work at 5 W for more than 7 h.
基金supported by the National Key R&D Program of China(2022YFA1504200)the National Natural Science Foundation of China(22122901)+1 种基金the Provincial Natural Science Foundation of Hunan(2021JC0008,2021JJ20024,and 2021RC3054)the Jiangsu Province Excellent Postdoctoral Program(2022ZB615)。
文摘The electrochemical oxidation of 5-hydroxymethylfurfural(HMFOR)in alkaline electrolyte is a promising strategy for producing high-value chemicals from biomass derivatives.However,the disproportionation of aldehyde groups under strong alkaline conditions and the polymerization of HMF to form humic substances can impact the purity of 2,5-furandicarboxylic acid(FDCA)products.The use of neutral electrolytes offers an alternative environment for electrolysis,but the lack of OH^(-)ions in the electrolyte often leads to low current density and low yields of FDCA.In this study,a sandwich-structured catalyst,consisting of Ru clusters confined between unilamellar MnO_(2)nanosheets(S-Ru/MnO_(2)),was used in conjunction with an electrochemical pulse method to realize the electrochemical conversion of5-hydroxymethylfurfural into FDCA in neutral electrolytes.Pulse electrolysis and the strong electron transfer between Ru clusters and MnO_(2)nanosheets help maintain Ru in a low oxidation state,ensuring high activity.The increased*OH generation led to a groundbreaking current density of 47 mA/cm^(2)at1.55 V vs.reversible hydrogen electrode(RHE)and an outstanding yield rate of 98.7%for FDCA in a neutral electrolyte.This work provides a strategy that combines electrocatalyst design with an electrolysis technique to achieve remarkable performance in neutral HMFOR.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.22101182)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110499)+2 种基金Shenzhen Science and Technology Program(No.JCYJ20210324095202006),Shenzhen University Young Teacher Research Project(No.000002110713)the Shccig-Qinling Program(No.2021JLM-27)the Jinchuan Group Co.Ltd.Chemical Environmental Protection Industry Joint Laboratory(No.20-0837).
文摘To improve the atomic utilization of metals and reduce the cost of industrialization,the one-step total monoatomization of macroscopic bulk metals,as opposed to nanoscale metals,is effective.In this study,we used a thermal diffusion method to directly convert commercial centimeter-scale Ni foam to porous Ni single-atom-loaded carbon nanotubes(CNTs).As expected,owing to the coating of single-atom on porous,highly conductive CNT carriers,Ni single-atom electrocatalysts(Ni-SACs)exhibit extremely high activity and selectivity in CO_(2)electroreduction(CO_(2)RR),yielding a current density of>350 mA/cm^(2),a selectivity for CO of>91%under a flow cell configuration using a 1 M potassium chloride(KCl)electrolyte.Based on the superior activity of the Ni-SACs electrocatalyst,an integrated gas-phase electrochemical zero-gap reactor was introduced to generate a significant amount of CO current for potential practical applications.The overall current can be increased to 800 mA,while maintaining CO Faradaic efficiencies(FEs)at above 90%per unit cell.Our findings and insights on the active site transformation mechanism for macroscopic bulk Ni foam conversion into single atoms can inform the design of highly active single-atom catalysts used in industrial CO_(2)RR systems.
文摘Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.
基金the financial support by the National Natural Science Foundation of China(NSFC,grant nos.21905288 and 51904288)Zhejiang Provincial Natural Science Foundation(LZ21B030001)+3 种基金K.C.Wong Education Foundation(GJTD-2019-13)Ningbo major special projects of the Plan“Science and Technology Innovation 2025”(grant nos.2018B10056 and 2019B10046)Ningbo 3315 ProgramYongjiang Talent Introduction Program(no.2021A-115-G)
文摘Developing stable and efficient nonprecious-metal-based oxygen evolution catalysts in the neutral electrolyte is a challenging but essential goal for various electrochemical systems.Particularly,cobalt-based spinels have drawn a considerable amount of attention but most of them operate in alkali solutions.However,the frequently studied Co-Fe spinel system never exhibits appreciable stability in nonbasic conditions,not to mention attract further investigation on its key structural motif and transition states for activity loss.Herein,we report exceptional stable Co-Fe spinel oxygen evolution catalysts(~30%Fe is optimal)in a neutral electrolyte,owing to its unique metal ion arrangements in the crystal lattice.The introduced iron content enters both the octahedral and tetrahedral sites of the spinel as Fe^(2+)and Fe^(3+)(with Co ions having mixed distribution as well).Combining density functional theory calculations,we find that the introduction of Fe to Co_(3)O_(4)lowers the covalency of metal-oxygen bonds and can help suppress the oxidation of Co^(2+/3+)and 0^(2-).It implies that the Co-Fe spinel will have minor surface reconstruction and less lattice oxygen loss during the oxygen evolution reaction process in comparison with Co_(3)O_(4)and hence show much better stability.These findings suggest that there is still much chance for the spinel structures,especially using reasonable sublattices engineering via multimetal doping to develop advanced oxygen evolution catalysts.
基金Supported by the Science&Technology Department of Jilin Province (Grant Nos.20180101199JC and 20180101204JC)Jilin Province/Jilin University Co-construction Project-Funds for New Materials (SXGJSF2017-3)。
文摘The V_2C compound,belonging to the group of two-dimensional transition metal carbonitrides,or MXenes,has demonstrated a promising electrochemical performance in capacitor applications in acidic electrolytes;however,there is evidence to suggest that V_2C is unstable in an acidic environment.On the other hand,the performance of V_2C in neutral aqueous electrolytes is still moderate,and has not yet been systematically studied.The charge storage mechanism in a V_2C electrode,employed in neutral aqueous electrolytes,is investigated via cyclic voltammetry testing and in situ x-ray diffraction(XRD).Good specific capacitances are achieved,specifically208 F/g in 0.5 M Li_2SO_4,225 F/g in 1 M MgSO_4,120 F/g in 1 M Na_2 SO_4,and 104 F/g in 0.5 M K_2SO_4.Using in situ XRD,we observe that,during the charge and discharge process,the c-lattice parameter shrinks or expands by up to 0.25 A in MgSO_4,and 0.29 A in Li_2SO_4 which demonstrates the intercalation/de-intercalation of cations into the d-V_2C layer.
基金Funding of Harbin Institute of Technology (Shenzhen) (DD45001015)NSFC/RGC Joint Research Scheme (Project N_City U123/15)+2 种基金the Science Technology and Innovation Committee of Shenzhen Municipality (JCYJ20130401145617276 and R-IND4903)City University of Hong Kong (PJ7004645)the Hong Kong Polytechnic University (1-BBA3) supported this work
文摘Inspired by the sophisticated artificial leather garment industry and toward enhancing wearability of energy storage devices, we demonstrate a polyurethane artificial leather supercapacitor with large sheet electrodes embedded in theleather layer simultaneously working as a polyelectrolyte. This design totally reserves textiles underneath and thus addresses the well-known challenge of wearing comfortability. It provides a revolutionary configuration of wearable supercapacitors: the artificial leather on garment is also a supercapacitor.Unlike the polyvinyl alcohol-based acidic electrolytes, which are widely used, sodium chloride is used to modify the intrinsically fluorescent polyurethane leather for ionic transportation, which has no harm to human. The fluorescent leather supercapacitor is easily transferrable from any arbitrary substrates to form various patterns, enabling multifunctionalities of practical wearability, fashion, and energy storage.
基金financial support from the National Natural Science Foundation of China(51771078,91545131 and 51371084)China Postdoctoral Science Foundation(No.2017M612455).
文摘Hydrogen evolution reaction(HER)in neutral medium suffers from slow kinetics as compared to that in alkaline or acidic conditions,owing to larger Ohmic loss and low proton concentration.Here we report that a self-supported nanoporous Au-SnO_(x)(NP Au-SnO_(x))catalyst with gradient tin oxide surface could significantly enhance HER activity in neutral buffer solution(0.2 M PBS).The NP Au-SnO_(x)catalyst exhibits a low onset overpotential of 38 mV and a small Tafel slope of 79 mV dec^(−1).The current density of 10 mA cm^(−2)is manifested at an overpotential as low as 148 mV,representing the comparable performance of Pt/C catalyst.This high catalytic activity can retain at least 10 hours without any detectable decay.The superior HER activity is proposed to originate from the gradient SnO_(x)structure and metal/oxide interfaces in nanoporous ligaments.Furthermore,the X-ray photoelectron spectroscopy reveals that the gradient oxide in the ligament is remarkably stable during long-term reaction.
基金supported by the National Natural Science Foundation of China(22101182)the Shenzhen Science and Technology Program(Nos.JCYJ20210324095202006,JCYJ20220531095813031,and JCYJ20230807140700001)Guangdong Basic and Applied Basic Research Foundation(2022A1515010318).
文摘Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO_(2)reduction reaction(CO_(2)RR)toward multi-carbon(C2+)products,primarily by suppressing the parasitic hydrogen evolution reaction and facilitating a localized CO_(2)/CO concentration at the electrode.Building upon this approach,we developed surface-functionalized catalysts with exceptional activity and selectivity for electrocatalytic CO_(2)RR to C_(2+)in a neutral electrolyte.Employing CuO nanoparticles coated with hexaethynylbenzene organic molecules(HEB-CuO NPs),a remarkable C_(2+)Faradaic efficiency of nearly 90%was achieved at an unprecedented current density of 300 mA cm^(-2),and a high FE(>80%)was maintained at a wide range of current densities(100-600 mA cm^(-2))in neutral environments using a flow cell.Furthermore,in a membrane electrode assembly(MEA)electrolyzer,86.14%FEC2+was achieved at a partial current density of 387.6 mA cm^(-2)while maintaining continuous operation for over 50 h at a current density of 200 mA cm^(-2).In-situ spectroscopy studies and molecular dynamics simulations reveal that reducing the coverage of coordinated K⋅H2O water increased the probability of intermediate reactants(CO)interacting with the surface,thereby promoting efficient C-C coupling and enhancing the yield of C_(2+)products.This advancement offers significant potential for optimizing local micro-environments for sustainable and highly efficient C_(2+)production.
基金Fundamental Research Funds for the Central UniversitiesChinese Academy of SciencesNational Natural Science Foundation of China,Grant/Award Numbers:12375301,21503227。
文摘Electrocatalysis,which involves oxidation and reduction reactions with direct electron transfer,is essential for a variety of clean energy conversion devices.Currently,the vast majority of studies regarding electrocatalysis reactions focus on strong acidic or alkaline media because of the higher catalytic activity.Nevertheless,some inherent drawbacks,including the corrosive environment,expensive proton exchange membranes,and side effects,are still hard to break through.A sustainably promising way to overcome these shortcomings is to deploy neutral/near-neutral electrolytes for electrocatalysis reactions.Unfortunately,insufficient research in this area due to the lack of attention to related issues has slowed down the development process.In this review,we systematically review the catalytic reaction mechanisms,neutral electrolytes,electrocatalysts,and modification strategies carried out in neutral media on the three most common electrocatalytic reactions,that is,hydrogen evolution reaction,oxygen reduction reaction,and oxygen evolution reaction.Furthermore,the advanced characterization tools for guiding catalyst synthesis and mechanistic studies are also summarized.Eventually,we propose some challenges and perspectives on electrocatalysis reactions in neutral media and hope it will attract more research interest and provide guidance in neutral electrocatalysis.
基金supported by the Science and Technology Foundation of Henan Province(No.192102210044)the National Natural Science Foundation of China(No.U1904171)the Young Backbone Teachers Training Program Foundation of Henan University of Technology,and the Innovative Funds Plan of Henan University of Technology(No.2020ZKCJ04).
文摘Conductive metal-organic frameworks(c-MOFs)are promising active electrode materials for electrochemical double-layer capacitors with a performance that already exceeds most carbon-based materials.However,their excellent supercapacitance is primarily based on organic or alkaline electrolytes,which largely impede their broad applications and sustainabilities.In this work,we propose a new synthesis approach for fabricating carbon nanotubes and c-MOFs(CNT@MOFs)core–shell structures,which result in high supercapacitance in neutral aqueous electrolytes.We identify that CNTs provide abundant active sites to ensure high capacitance,and Ni3(2,3,6,7,10,11-hexaiminotriphenylene(HITP))2 nanoarrays that in situ grow on the surface of CNTs bundles can significantly improve the conductivity and provide enough ion transport pathways in aqueous electrolytes.Specifically,using CNT@MOFs core-shell structures as an electrode,we obtained a high initial capacitance of 150.7 F·g^(−1) at 0.1 A·g^(−1) in 1 M Na2SO4 solution and good capacity retention of 83.5%after 10,000 cycles at 4 A·g^(−1).We also found that the carboxyl groups on the surface of CNTs provide better anchor sites for the in situ growth of c-MOF,which promotes the uniform growth of c-MOF shells on the CNT surface and improves aqueous electrolyte accessibility.We believe that the high supercapacitance in aqueous electrolytes reported in this work would provide a good prospect for deploying c-MOF based energy storage devices into biomedical and other healthcare electronic applications.
基金financially supported by the National Natural Science Foundation of China (21706090 and 51772135)the Ministry of Education of China (6141A02022516)+3 种基金the Natural Science Foundation of Guangdong Province (2014A030306010)Jinan University (88016105)the Natural Science Foundation of Guangzhou (201904010049)the Fundamental Research Foundation for the Central Universities (21617326)。
文摘Neutral Zn-air batteries(ZABs) have attracted much attention due to the enhanced lifespan and stability.However, their development is suppressed by the poor catalytic properties of the air-electrocatalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER). Hence,the exploration of highly efficient electrocatalysts for neutral ZABs is critical. Herein, we designed an economical heterostructure of Pt nanoparticle-modified Zn nanoplates(Pt/Zn NPs). Compared with commercial Pt/C electrocatalyst, our Pt/Zn heterostructure exhibits comparable catalytic properties and ultrahigh stability in neutral media. The heterostructure can reduce the dosage of Pt and offer sufficient active sites,resulting in enhanced catalytic properties for ORR/OER in neutral media. When applied to neutral ZABs as air cathode,our heterostructure exhibits a high power density of 45 mW cm^(-2) and excellent stability of more than 850 cycles with negligible decay, making it the most efficient and robust one in neutral electrolyte. This approach opens a new avenue to strategically design catalysts with high activity for neutral ZABs, rendering them potential in portable and wearable electronic devices.
基金supported by the Ministry of Science and Technology(2016YFA0203302)the National Natural Science Foundation of China(21875042,21634003,51573027 and 11227902)+3 种基金Science and Technology Commission of Shanghai Municipality(16JC1400702 and 18QA1400800)Shanghai Municipal Education Commission(2017-01-07-00-07-E00062)Yanchang Petroleum Groupthe Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Developing efficient electrocatalysts for the oxygen evolution reaction(OER)under neutral conditions is important for microbial electrolysis cells(MECs).However,the OER kinetics in neutral electrolytes at present are extremely sluggish,resulting in high overpotentials that greatly limit the energy conversion efficiencies of MECs.Previous studies failed to probe the adsorbates on surface metal sites of catalysts at the atomic scale and elucidate their influence on the catalytic activities,which has impeded the rational design of efficient neutral OER catalysts with optimal surface structures.Here,using in situ transmission electron microscopy(TEM),in situ X-ray photoelectron spectroscopy(XPS)and in situ low-energy ion scattering studies,we have identified,for the first time,that the electrochemically activated adsorbates on surface metal sites play a critical role in boosting the neutral OER activities of Ru-Ir binary oxide(RuxIryO2)catalysts.The adsorbate-activated RuxIryO2on a glassy carbon electrode achieved a low overpotential of 324 m V at10 m A cm-2in neutral electrolyte,with a 36-fold improvement in turnover frequency compared with that of Ir O2benchmark.Upon application in an MEC system,the resulting full cell showed a decreased voltage of 1.8 V,200 m V lower than the best value reported to date,facilitating efficient synthesis of poly(3-hydroxybutyrate)from bioelectrochemical CO2reduction.Density functional theory(DFT)studies revealed that the enhanced OER activity of RuxIryO2catalyst arose from local structural distortion of adjacent adsorbate-covered Ru octahedra at the catalyst surface and the consequently decreased adsorption energies of OER intermediates on Ir active center.
基金supported in part by the National Natural Science Foundation of China(Nos.51925102 and 52273277)H.-X.Z.acknowledges funding from the National Natural Science Foundation of China Outstanding Youth Science Foundation of China(Overseas).
文摘Electrocatalytic reduction of nitrate(NO_(3)^(−))and nitride(NO_(2)^(−))to ammonia(NH3)is of wide interest as a promising alternative to the energy-intensive Haber-Bosch route for mitigating the vast energy consumption and the accompanied carbon dioxide emission,as well as benefiting for the relevant sewage treatment.However,exploring an efficient and low-cost catalyst with high atomic utilization that can effectively facilitate the slow multi-electron transfer process remains a grand challenge.Herein,we present an efficient hydrogenation of NO_(3)^(−)/NO_(2)^(−)species to NH3 in both alkaline and neutral environments over the Fe_(2)(MoO_(4))_(3)derived hybrid electrocatalyst with the metallic Fe site on FeMoO_(4)(Fe/FeMoO_(4)).The Mo ingredient can play a synergistically positive role in further promoting the NH_(3) production on Fe.As a result,Fe/FeMoO_(4)behaves well in the electrochemical NH_(3) generation from NO_(2)^(−)with a maximum NH_(3) Faradaic efficiency(FE)of 96.53%and 87.68%in alkaline and neutral electrolyte,corresponding to the NH_(3) yield rate of 640.68 and 302.56 mg·h^(−1)·mg_(cat.)^(−1),respectively,which outperforms the Fe and Mo counterpart and other similar catalyst,showing the robust catalytic capacity of each active site.
基金supported by the National Natural Science Foundation of China(No.22379054)funding at Jiangnan Universitythe Young Elite Scientists Sponsorship Program by CAST(No.2024QNRC001).
文摘The primary objective in researching the anode side of electrochemical CO_(2) reduction reaction(CO_(2)RR)is to substitute the frequently employed Ir anodic catalyst with more readily available and cost-effective non-noble metal oxide.When organic molecules are loaded on the Cu_(2)O surface,a synergistic effect can be formed between different components.This effect can accelerate electron transfer,provide new active sites,and further enhance the performance of reactants of oxygen evolutionreaction(OER).This study proposes a new type of anodic catalyst,PDI/Cu_(2)O/Cu,and investigates its OER activity and three other anodic catalysts(IrO_(2)/Ti mesh,Ni foam,and Pt mesh)in the CO_(2)RR system.The results show that PDI/Cu_(2)O/Cu exhibited OER activity with an overpotential of 422.1 mV to drive a current density of 70 mA·cm^(−2) in neutral electrolytes.Compared to IrO_(2)/Ti mesh,the overpotential of perylene tetracarboxylic di-(propyl imidazole)(PDI)/Cu_(2)O/Cu is decreased by 490 mV.This significantly lowers the energy consumption of the CO_(2)RR system without compromising the performance of CO_(2)RR.Furthermore,the use of precious metal materials is unnecessary,leading to a substantial reduction in the cost of the anodic catalyst.PDI/Cu_(2)O/Cu holds the potential to serve as a non-precious metal alternative to Ir in neutral electrolytes as an anodic catalyst.
