To develop graphene-based nanomaterials as reliable catalysts for electrochemical energy conversion and storage systems(e.g.PEM fuel cells,metal–air batteries,etc.),it is imperative to critically understand their per...To develop graphene-based nanomaterials as reliable catalysts for electrochemical energy conversion and storage systems(e.g.PEM fuel cells,metal–air batteries,etc.),it is imperative to critically understand their performance changes and correlated material degradation processes under different operational conditions.In these systems,hydrogen peroxide(H_(2)O_(2))is often an inevitable byproduct of the catalytic oxygen reduction reaction,which can be detrimental to the catalysts,electrodes,and electrolyte materials.Here,we studied how the electrocatalytic performance changes for a heterogeneous nanocatalyst named nitrogen-doped graphene integrated with a metal–organic framework(N-G/MOF)by the effect of H_(2)O_(2),and correlated the degradation process of the catalyst in terms of the changes in elemental compositions,chemical bonds,crystal structures,and morphology.The catalyst samples were treated with five different concentrations of H_(2)O_(2) to emulate the operational conditions and examined to quantify the changes in electrocatalytic performances in an alkaline medium,elemental composition and chemical bonds,crystal structure,and morphology.The electrocatalytic performance considerably declined as the H_(2)O_(2) concentration reached above 0.1 M.The XPS analyses suggest the formation of different oxygen functional groups on the material surface,the breakdown of the material's C–C bonds,and a sharp decline in pyridinic-N functional groups due to gradually harsher H_(2)O_(2) treatments.In higher concentrations,the H_(2)O_(2)-derived radicals altered the crystalline and morphological features of the catalyst.展开更多
High entropy materials(HEMs)are the promising electrocatalysts for anion exchange membrane electrolyser(AEMs)and proton exchange membrane fuel cells(PEMFCs)due to the intriguing cocktail effect,wide design space,tailo...High entropy materials(HEMs)are the promising electrocatalysts for anion exchange membrane electrolyser(AEMs)and proton exchange membrane fuel cells(PEMFCs)due to the intriguing cocktail effect,wide design space,tailorable electronic structure,and entropy stabilization effect.The precise fabrication of HEMs with functional nanostructures provides a crucial avenue to optimize the adsorption strength and catalytic activity for electrocatalysis.This review comprehensively summarizes the development of HEMs,focusing on the principles and strategies of structural design,and the catalytic mechanism towards hydrogen evolution reaction,oxygen evolution reaction and oxygen reduction reaction for the development of high-performance electrocatalysts.The complexity inherent in the interactions between different elements,the changes in the d-band center and the Gibbs free energies during the catalytic progress,as well as the coordination environment of the active sites associated with the unique crystal structure to improve the catalytic performance are discussed.We also provide a perspective on the challenges and future development direction of HEMs in electrocatalysis.This review will contribute to the design and development of HEMs-based catalysts for the next generation of electrochemical applications.展开更多
To simultaneously reduce noble metal Pd usage and enhance electrocatalytic performance for methanol oxidation,Pd/Co2O3 composites with ultrafine three-dimensional(3D)nanoporous structures were designed and synthesized...To simultaneously reduce noble metal Pd usage and enhance electrocatalytic performance for methanol oxidation,Pd/Co2O3 composites with ultrafine three-dimensional(3D)nanoporous structures were designed and synthesized by simple one-step dealloying of a melt-spun Al-Pd-Co alloy with an alkaline solution.Their electrocatalytic activity in alkaline media was determined by a Versa-STAT MC workstation.The results indicate that the typical sizes of the ligaments and pores of the composites were approximately 8-9 nm.The Co2O3 was uniformly distributed on the Pd ligament surface.Among the as-prepared samples,the nanoporous Pd/Co2O3 composite generated from dealloying of the Al84.5Pd15Co0.5 alloy had the best electrocatalytic activity,and its activity was enhanced by approximately 230%compared with the nanoporous Pd from dealloying of Al85Pd15.The improvement of the electrocatalytic performance was mainly attributed to the electronic modification effect between Pd and Co as well as the bifunctional mechanism between Pd and Co2O3.展开更多
Metal-organic frameworks(MOFs) have showed high promise in CO_(2)-electroreduction, yet their generally insufficient conductivity or low electron-transfer efficiency have largely restricted the wide-spread application...Metal-organic frameworks(MOFs) have showed high promise in CO_(2)-electroreduction, yet their generally insufficient conductivity or low electron-transfer efficiency have largely restricted the wide-spread applications. Herein, fullerene molecules(i.e., C60and C70) have been successfully introduced into the pore-channels of a Co-porphyrin based MOF through a facile strategy. Thus-obtained hybrid materials present higher electron-transfer ability, enhanced CO_(2)adsorption-enthalpy and CO_(2)electroreduction activity. Notably, the charge transfer resistance(Rct) of C60@MOF-545-Co is almost 5 times lower of than that of MOF-545-Co, as well as 1.5 times increased for the CO_(2)adsorption enthalpy. As expect, the FECO of C60@MOF-545-Co(97.0%) is largely higher than MOF-545-Co(70.2%), C60@MOF-545(19.4%), C60(11.5%)and physical mixture(70.3%) and presented as one of the best CO_(2)electroreduction catalysts reported in H-cell system. The facile strategy would give rise to new insight into the exploration of powerful MOFbased hybrid materials in high-efficiency CO_(2)electroreduction.展开更多
Monotungsten carbide and titania nanocomposite with core-shell（WC@TiO2）structure was prepared by a new approach of spray drying and reduction-carbonization reaction,with titania nanopowder and ammonium metatungstate...Monotungsten carbide and titania nanocomposite with core-shell（WC@TiO2）structure was prepared by a new approach of spray drying and reduction-carbonization reaction,with titania nanopowder and ammonium metatungstate as precursors,methane as carbon source,and hydrogen as reduction gas.The sample was characterized by X-ray diffraction,scanning electron microscope,high resolution transmission electron microscope and X-ray energy dispersion spectroscopy.The results show that its crystal phase is composed of brookite,tungsten and monotungsten carbide.The morphology of the sample particle is irregular sphere-like,with a diameter smaller than 100 nm.Its chemical components are titanium,tungsten,carbon and oxygen.Monotungsten carbide nanoparticles lie on the surface of titania core and form an incomplete shell around titania core in the nanocomposite.The measurement with a microelectrode system of three electrodes shows that the sample is electrocatalytic active to nitrophenol in basic solution at room temperature.Its peak potential is at0.988 V（vs saturated calomel electrode （SCE））,which is more negative than the peak potential,0.817 V（vs SCE）,of mesoporous monotungsten carbide, and its peak current is 8.809μA,which is higher than the peak current,4.058μA,of mesoporous monotungsten carbide.The hydrogen generation potential of the sample is at1.199 V（vs SCE）,which is more negative than that of pure nanosized monotungsten carbide at1.100 V（vs SCE）.These results show that the presence of titania in the sample can lower the peak potential of nitrophenol electrocatalysis and its hydrogen generation potential,and increase its peak current of nitrophenol electrocatalysis in basic solution at room temperature.This indicates a synergistic effect of titania and monotungsten carbide in electrocatalysis.展开更多
Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was pr...Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was prepared by solvothermal method,and then used as precursor to prepare NiFe-based MOF-derived materials by pyrolysis.The effects of different metal ratios and pyrolysis temperatures on the sample structure and OER electrocatalytic performance were investigated and compared.The experimental results showed that when the metal molar ratio was Fe:Ni=1:5 and the pyrolysis temperature was 450℃,the sample(FeNi_(5)-MOF-450)exhibits a composite structure of Ni Fe_(2)O_(4)/FeNi_(3)/C and owns the superior electrocatalytic activity in OER.When the current density is 100 mA·cm^(-2),the overpotential of the sample was 377 mV with Tafel slope of 56.2 mV·dec^(-1),which indicates that FeNi_(5)-MOF-450 exhibits superior electrocatalytic performance than the commercial RuO_(2).Moreover,the long-term stability of FeNi_(5)-MOF-450 further promotes its development in OER.This work demonstrated that the regulatory methods such as component optimization can effectively improve the OER catalytic performance of NiFe-based MOF-derived materials.展开更多
A novel plastic/multi-walled carbon nanotube（MWNTs）-nickel（Ni）-platinum（Pt） electrode（PMNP） is prepared by chemical-reducing Pt onto the surface of Ni film covered plastic/MWNTs（PM） substrate. The MWNTs are ...A novel plastic/multi-walled carbon nanotube（MWNTs）-nickel（Ni）-platinum（Pt） electrode（PMNP） is prepared by chemical-reducing Pt onto the surface of Ni film covered plastic/MWNTs（PM） substrate. The MWNTs are adhered by a piece of commercial double faced adhesive tape on the surface of plastic paper and the Ni film is prepared by a simple electrodeposition method. The morphology and phase structure of the PMNP electrode are characterized by scanning electron microscopy,transmission electron microscope and X-ray diffractometer. The catalytic activity of the PMNP electrode for Na BH4 electrooxidation is investigated by means of cyclic voltammetry and chronoamperometry. The catalyst combines tightly with the plastic paper and exhibits a good stability. MWNTs serve as both conductive material and hydrogen storage material and the Ni film and Pt are employed as electrochemical catalysts. The PMNP electrode exhibits a high electrocatalytic performance and the oxidation current density reaches to 10.76 A/（mg·cm） in 0.1 mol/dm3 Na BH4at0 V,which is much higher than those in the previous reports. The using of waste plastic reduces the discarding of white pollution and consumption of metal resources.展开更多
Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclu...Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclusters,serving as exemplary models,significantly expand the range of accessible structures through diverse cores and ligands,creating an exceptional platform for the investigation of catalytic reactions.Notably,ligand‐protected Au nanoclusters(NCs)with precisely defined core numbers offer a distinct advantage in elucidating the correlation between their specific structures and the reaction mechanisms in electrocatalysis.The strategic modulation of the fine microstructures of Au NCs presents crucial opportunities for tailoring their electrocatalytic performance across various reactions.This review delves into the profound structural effects of Au NC cores and ligands in electrocatalysis,elucidating their underlying mechanisms.A detailed exploration of the fundamentals of Au NCs,considering core and ligand structures,follows.Subsequently,the interaction between the core and ligand structures of Au NCs and their impact on electrocatalytic performance in diverse reactions are examined.Concluding the discourse,challenges and personal prospects are presented to guide the rational design of efficient electrocatalysts and advance electrocatalytic reactions.展开更多
Cobalt-based electrocatalysts take advantage of potentially harmonizable microstructure and flexible coupling effects compared to commercial noble metal-based catalytic materials.However,conventional water electrolysi...Cobalt-based electrocatalysts take advantage of potentially harmonizable microstructure and flexible coupling effects compared to commercial noble metal-based catalytic materials.However,conventional water electrolysis systems based on cobalt-based monofunctional hydrogen evolution reaction(HER)or oxygen evolution reaction(OER)catalysts have certain shortcomings in terms of resource utilization and universality.In contrast,cobalt-based bifunctional catalysts(CBCs)have attracted much attention in recent years for overall water splitting systems because of their practicality and reduced preparation cost of electrolyzer.This review aims to address the latest development in CBCs for total hydrolysis.The main modification strategies of CBCs are systematically classified in water electrolysis to provide an overview of how to regulate their morphology and electronic configuration.Then,the catalytic performance of CBCs in total-hydrolysis is summarized according to the types of cobalt-based phosphides,sulfides and oxides,and the mechanism of strengthened electrocatalytic ability is emphasized through combining experiments and theoretical calculations.Future efforts are finally suggested to focus on exploring the dynamic conversion of reaction intermediates and building near-industrial CBCs,designing advanced CBC materials through micro-modulation,and addressing commercial applications.展开更多
The key to obtaining high intrinsic catalytic activity of Me-N_(x)-C electrocatalysts for Zn-air batteries is to form high-density bifunctional Me-N_(x) active sites during the pyrolysis of the precursor while maintai...The key to obtaining high intrinsic catalytic activity of Me-N_(x)-C electrocatalysts for Zn-air batteries is to form high-density bifunctional Me-N_(x) active sites during the pyrolysis of the precursor while maintaining structural stability.In this study,a host-vip spatial confinement strategy was utilized to synthesize a composite catalyst consisting of Co_(3)Fe_(7) nanoparticles confined in an N-doped carbon network.The coupling between the host(MIL-88B)and vip(cobalt porphyrin,CoPP)produces highdensity bimetallic atomic active sites.By controlling the mass of vip molecules,it is possible to construct precursors with the highest activity potential.The Co_(3)Fe_(7)/NC material with a certain amount of the vip displays a better electrocatalytic performance for both oxygen reduction reaction and oxygen evolution reaction with a half-wave potential(E_(1/2))of 0.85 V and an overpotential of 1.59 V at 10 mAcm^(-2),respectively.The specific structure of bimetallic active centers is verified to be FeN2-CoN_(4) using experimental characterizations,and the oxygen reaction mechanism is explored by in-situ characterization techniques and first-principles calculations.The Zn-air battery assembled with Co_(3)Fe_(7)/NC cathode exhibits a remarkable open-circuit voltage of 1.52 V,an exceptional peak power density of 248.1mWcm^(-2),and stable cycling stability over 1000 h.Particularly,the corresponding flexible Zn-air battery affords prominent cycling performance under different bending angles.This study supplies the idea and method of designing catalysts with specific structures at the atomic and electronic scales for breaking through the large-scale application of electrocatalysts based on oxygen reactions in fuel cells/metal-air batteries.展开更多
Today,nanocrystals enclosed by high-index facets(HIFs)are attracting widely attentions of researchers due to their tremendous potential in the field of catalysis,especially in electrocatalysis,such as electro-oxidatio...Today,nanocrystals enclosed by high-index facets(HIFs)are attracting widely attentions of researchers due to their tremendous potential in the field of catalysis,especially in electrocatalysis,such as electro-oxidation of small organic molecule(such as formic acid,methanol,and ethanol),oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER).However,the practical applications of nanocrystals enclosed by HIFs still face many limitations in preparations of advanced electrocatalysts,including preparation strategy,limited life-time and stability.The development of advanced electrocatalysts enclosed with HIFs is crucial for solving these problems if the large-scale application of them is to be realized.Herein,we firstly detailedly demonstrate the identification methods of nanocrystals enclosed by HIFs,and then preparation strategies are elaborated in detail in this review.Current advanced nanocrystals enclosed by HIFs in electrocatalytic application are also summarized and we present representative achievements to further reveal the relationship of excellent electrocatalytic performance and nanocrystals with HIFs.Finally,we predict the remaining challenges and present our perspectives with regards of design strategies of improving electrocatalytic performance of Ptbased catalysts in the future.展开更多
Hydrogen is considered as the promising energy carrier to substitute traditional fossil fuel,due to its cleanliness,renewability and high energy density.Water electrolysis is a simple and eonvenient technology for hyd...Hydrogen is considered as the promising energy carrier to substitute traditional fossil fuel,due to its cleanliness,renewability and high energy density.Water electrolysis is a simple and eonvenient technology for hydrogen production.The efficiency of water electrolysis for hydrogen production is limited by the electrocatalytic performances on hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The exorbitant Pt-and Ir-/Ru-based electrocatalysts as optimal HER and OER electrocatalysts,respectively,restrict water electrolysis development.Recently,non-precious metal-based high-entropy electrocatalysts have exhibited excellent electrocatalytic activities and long-term stabilities for water electrolysis,as promising precious cataly st candidates.Therefore,the construction of the high-entropy electroc atalysts is vital to water electrolysis industry.Electrodeposition technology is an efficient method for the preparation of high-entropy electrocatalysts due to its simple,fast,energy-saving and environmental-friendly advantages.Multi-component co-precipitation facilely occurs during the electroredox in electrodeposition processes.High-entropy alloys,oxides,(oxy)hydroxides,phosphides and phosphorus sulfide oxides have been successfully prepared by galvanostatic,potentiostatic electrodeposition,cyclic voltammetry,pulse,nanodroplet-mediated and cathodic plasma electrodeposition techniques.Hence,introduction of the development of high-entropy electrocatalysts synthesized by electrodeposition technology is significant to researchers and industries.Challenges and outlooks are also concluded to boost the industrial application of electrodeposition in water electrolysis and other energy conversion areas.展开更多
Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes.High-temperature pyrolysis(>500°C)methods are used to control their crystalline order...Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes.High-temperature pyrolysis(>500°C)methods are used to control their crystalline orderings,critical to their electrocatalytic activity and durability.However,the high temperature would cause severe aggregation,resulting in a low catalytic active surface area.Significant research efforts have been devoted to addressing this issue.This short review summarizes recent research progress on synthesizing noble metal-based intermetallic electrocatalysts by space-confined pyrolysis.We focus on three strategies:isolation in pores,coverture by shells,and immobilization by salts.The advantages and existing problems of different methods are highlighted.Last,important issues to be addressed in future research are also discussed.We hope that this article will stimulate future research to develop high-performance intermetallic catalysts for practical applications.展开更多
Imparting one-dimensional(1D)ultrafine organic nanowires with tailored ligands and atomically-dispersed central noble metal to craft high-performance hybrid single atom electrocatalysts offers a prospective yet challe...Imparting one-dimensional(1D)ultrafine organic nanowires with tailored ligands and atomically-dispersed central noble metal to craft high-performance hybrid single atom electrocatalysts offers a prospective yet challenging approach for the advancement in hydrogen evolution reactions(HER).Herein,we report the evaporation-induced self-assembly of sequence-defined amphiphilic alternating azopeptoids(AAAPs)to generate photo-responsive and micron-scale ultrafine peptoid nanowires(UFPNWs)with a diameter of~1.8 nm via pendants'hydrophobic conjugate stacking mechanism,exemplifying the finest biomimetic polymers-based nanowires to date.A series of 1D UFPNWs-based single-atom catalysts(SACs)were meticulously fabricated using the chelation interaction between Pt ions and nitrogenous ligands.The photo-controllable electrocatalytic performance was evaluated toward acidic HER,which was highly dependent on the presence of Pt elements,the structural characteristic of supports,and the peripheral coordination microenvironment of the center Pt atoms.Notably,the Pt-based hybrid SACs using terpyridine-modified UFPNWs as support presented favorable electrocatalytic capacity with an overpotential of~20 m V at a current density of 10 m A cm^(-2),and a mass activity of 89.6 times greater than commercial Pt/C catalyst.Our work paves an appealing avenue for the construction of stimuli-responsive 1D organic nanowire-based hybrid catalysts with controllable electrocatalytic HER performance.展开更多
Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considera...Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considerable research efforts have been devoted to construct advanced fiber materials possessing conductive network(to facilitate efficient electron transport)and large specific surface area(to support massive catalytically active sites)to boost electrocatalysis performance.Herein,we focused on recent advances in fiber-based electrocatalyst with enhanced electrocatalytic activity.Moreover,the synthesis,structure,and properties of fiber materials and their applications in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,carbon dioxide reduction reaction,and nitrogen reduction reaction are discussed.Finally,the research challenges and future prospects of fiber materials in electrocatalysis applications are proposed.展开更多
文摘To develop graphene-based nanomaterials as reliable catalysts for electrochemical energy conversion and storage systems(e.g.PEM fuel cells,metal–air batteries,etc.),it is imperative to critically understand their performance changes and correlated material degradation processes under different operational conditions.In these systems,hydrogen peroxide(H_(2)O_(2))is often an inevitable byproduct of the catalytic oxygen reduction reaction,which can be detrimental to the catalysts,electrodes,and electrolyte materials.Here,we studied how the electrocatalytic performance changes for a heterogeneous nanocatalyst named nitrogen-doped graphene integrated with a metal–organic framework(N-G/MOF)by the effect of H_(2)O_(2),and correlated the degradation process of the catalyst in terms of the changes in elemental compositions,chemical bonds,crystal structures,and morphology.The catalyst samples were treated with five different concentrations of H_(2)O_(2) to emulate the operational conditions and examined to quantify the changes in electrocatalytic performances in an alkaline medium,elemental composition and chemical bonds,crystal structure,and morphology.The electrocatalytic performance considerably declined as the H_(2)O_(2) concentration reached above 0.1 M.The XPS analyses suggest the formation of different oxygen functional groups on the material surface,the breakdown of the material's C–C bonds,and a sharp decline in pyridinic-N functional groups due to gradually harsher H_(2)O_(2) treatments.In higher concentrations,the H_(2)O_(2)-derived radicals altered the crystalline and morphological features of the catalyst.
基金supported by the Guangdong Basic and Applied Basic Research Fund Project(2022A1515140061,No.11000-2344014)Startup Foundation for Postdoctor by Dongguan University of Technology(No.11000-221110149)the High-level Talents Program(contract number 2023JC10L014)of the Department of Science and Technology of Guangdong Province。
文摘High entropy materials(HEMs)are the promising electrocatalysts for anion exchange membrane electrolyser(AEMs)and proton exchange membrane fuel cells(PEMFCs)due to the intriguing cocktail effect,wide design space,tailorable electronic structure,and entropy stabilization effect.The precise fabrication of HEMs with functional nanostructures provides a crucial avenue to optimize the adsorption strength and catalytic activity for electrocatalysis.This review comprehensively summarizes the development of HEMs,focusing on the principles and strategies of structural design,and the catalytic mechanism towards hydrogen evolution reaction,oxygen evolution reaction and oxygen reduction reaction for the development of high-performance electrocatalysts.The complexity inherent in the interactions between different elements,the changes in the d-band center and the Gibbs free energies during the catalytic progress,as well as the coordination environment of the active sites associated with the unique crystal structure to improve the catalytic performance are discussed.We also provide a perspective on the challenges and future development direction of HEMs in electrocatalysis.This review will contribute to the design and development of HEMs-based catalysts for the next generation of electrochemical applications.
基金Project(51371135)supported by the National Natural Science Foundation of China
文摘To simultaneously reduce noble metal Pd usage and enhance electrocatalytic performance for methanol oxidation,Pd/Co2O3 composites with ultrafine three-dimensional(3D)nanoporous structures were designed and synthesized by simple one-step dealloying of a melt-spun Al-Pd-Co alloy with an alkaline solution.Their electrocatalytic activity in alkaline media was determined by a Versa-STAT MC workstation.The results indicate that the typical sizes of the ligaments and pores of the composites were approximately 8-9 nm.The Co2O3 was uniformly distributed on the Pd ligament surface.Among the as-prepared samples,the nanoporous Pd/Co2O3 composite generated from dealloying of the Al84.5Pd15Co0.5 alloy had the best electrocatalytic activity,and its activity was enhanced by approximately 230%compared with the nanoporous Pd from dealloying of Al85Pd15.The improvement of the electrocatalytic performance was mainly attributed to the electronic modification effect between Pd and Co as well as the bifunctional mechanism between Pd and Co2O3.
基金financially supported by the National Natural Science Foundation of China (Nos. 22171139 and 21901122)Natural Science Foundation of Educational Commission of Anhui Province of China (No. KJ2020A0240)+1 种基金the Natural Science Research of Jiangsu Higher Education Institutions of China (No.19KJB150011)Project funded by China Postdoctoral Science Foundation (No. 2019M651873)。
文摘Metal-organic frameworks(MOFs) have showed high promise in CO_(2)-electroreduction, yet their generally insufficient conductivity or low electron-transfer efficiency have largely restricted the wide-spread applications. Herein, fullerene molecules(i.e., C60and C70) have been successfully introduced into the pore-channels of a Co-porphyrin based MOF through a facile strategy. Thus-obtained hybrid materials present higher electron-transfer ability, enhanced CO_(2)adsorption-enthalpy and CO_(2)electroreduction activity. Notably, the charge transfer resistance(Rct) of C60@MOF-545-Co is almost 5 times lower of than that of MOF-545-Co, as well as 1.5 times increased for the CO_(2)adsorption enthalpy. As expect, the FECO of C60@MOF-545-Co(97.0%) is largely higher than MOF-545-Co(70.2%), C60@MOF-545(19.4%), C60(11.5%)and physical mixture(70.3%) and presented as one of the best CO_(2)electroreduction catalysts reported in H-cell system. The facile strategy would give rise to new insight into the exploration of powerful MOFbased hybrid materials in high-efficiency CO_(2)electroreduction.
基金Supported by the National Natural Science Foundation of China（20476097） the Zhejiang Natural Science Foundation（Y4080209 Y406094）+1 种基金 the Science Plan of Zhejiang Province（2007F70039） the Scientific Starting Fund of Zhejiang University of Technology
文摘Monotungsten carbide and titania nanocomposite with core-shell（WC@TiO2）structure was prepared by a new approach of spray drying and reduction-carbonization reaction,with titania nanopowder and ammonium metatungstate as precursors,methane as carbon source,and hydrogen as reduction gas.The sample was characterized by X-ray diffraction,scanning electron microscope,high resolution transmission electron microscope and X-ray energy dispersion spectroscopy.The results show that its crystal phase is composed of brookite,tungsten and monotungsten carbide.The morphology of the sample particle is irregular sphere-like,with a diameter smaller than 100 nm.Its chemical components are titanium,tungsten,carbon and oxygen.Monotungsten carbide nanoparticles lie on the surface of titania core and form an incomplete shell around titania core in the nanocomposite.The measurement with a microelectrode system of three electrodes shows that the sample is electrocatalytic active to nitrophenol in basic solution at room temperature.Its peak potential is at0.988 V（vs saturated calomel electrode （SCE））,which is more negative than the peak potential,0.817 V（vs SCE）,of mesoporous monotungsten carbide, and its peak current is 8.809μA,which is higher than the peak current,4.058μA,of mesoporous monotungsten carbide.The hydrogen generation potential of the sample is at1.199 V（vs SCE）,which is more negative than that of pure nanosized monotungsten carbide at1.100 V（vs SCE）.These results show that the presence of titania in the sample can lower the peak potential of nitrophenol electrocatalysis and its hydrogen generation potential,and increase its peak current of nitrophenol electrocatalysis in basic solution at room temperature.This indicates a synergistic effect of titania and monotungsten carbide in electrocatalysis.
基金supported by the Shandong Natural Science Fund (No.ZR2020KB010)the Fundamental Research Funds for the Central Universities (No.22CX 07010A)。
文摘Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was prepared by solvothermal method,and then used as precursor to prepare NiFe-based MOF-derived materials by pyrolysis.The effects of different metal ratios and pyrolysis temperatures on the sample structure and OER electrocatalytic performance were investigated and compared.The experimental results showed that when the metal molar ratio was Fe:Ni=1:5 and the pyrolysis temperature was 450℃,the sample(FeNi_(5)-MOF-450)exhibits a composite structure of Ni Fe_(2)O_(4)/FeNi_(3)/C and owns the superior electrocatalytic activity in OER.When the current density is 100 mA·cm^(-2),the overpotential of the sample was 377 mV with Tafel slope of 56.2 mV·dec^(-1),which indicates that FeNi_(5)-MOF-450 exhibits superior electrocatalytic performance than the commercial RuO_(2).Moreover,the long-term stability of FeNi_(5)-MOF-450 further promotes its development in OER.This work demonstrated that the regulatory methods such as component optimization can effectively improve the OER catalytic performance of NiFe-based MOF-derived materials.
基金supported by the Fundamental Research Funds for the Central Universities (HEUCF201403018)the Heilongjiang Postdoctoral Fund (LBHZ13059)+1 种基金the China Postdoctoral Science Foundation (2014M561332)the National Natural Science Foundation of China (21403044)
文摘A novel plastic/multi-walled carbon nanotube（MWNTs）-nickel（Ni）-platinum（Pt） electrode（PMNP） is prepared by chemical-reducing Pt onto the surface of Ni film covered plastic/MWNTs（PM） substrate. The MWNTs are adhered by a piece of commercial double faced adhesive tape on the surface of plastic paper and the Ni film is prepared by a simple electrodeposition method. The morphology and phase structure of the PMNP electrode are characterized by scanning electron microscopy,transmission electron microscope and X-ray diffractometer. The catalytic activity of the PMNP electrode for Na BH4 electrooxidation is investigated by means of cyclic voltammetry and chronoamperometry. The catalyst combines tightly with the plastic paper and exhibits a good stability. MWNTs serve as both conductive material and hydrogen storage material and the Ni film and Pt are employed as electrochemical catalysts. The PMNP electrode exhibits a high electrocatalytic performance and the oxidation current density reaches to 10.76 A/（mg·cm） in 0.1 mol/dm3 Na BH4at0 V,which is much higher than those in the previous reports. The using of waste plastic reduces the discarding of white pollution and consumption of metal resources.
基金Guangzhou Key R&D Program/Plan Unveiled Flagship Project,Grant/Award Number:20220602JBGS02Guangzhou Basic and Applied Basic Research Project,Grant/Award Number:202201011449+3 种基金Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology,Grant/Award Numbers:FC202220,FC202216Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2021A1515010167,2022A1515011196National Natural Science Foundation of China,Grant/Award Numbers:21975292,21978331,22068008,52101186Training Program of the Major Research Plan of the National Natural Science Foundation of China,Grant/Award Number:92061124。
文摘Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclusters,serving as exemplary models,significantly expand the range of accessible structures through diverse cores and ligands,creating an exceptional platform for the investigation of catalytic reactions.Notably,ligand‐protected Au nanoclusters(NCs)with precisely defined core numbers offer a distinct advantage in elucidating the correlation between their specific structures and the reaction mechanisms in electrocatalysis.The strategic modulation of the fine microstructures of Au NCs presents crucial opportunities for tailoring their electrocatalytic performance across various reactions.This review delves into the profound structural effects of Au NC cores and ligands in electrocatalysis,elucidating their underlying mechanisms.A detailed exploration of the fundamentals of Au NCs,considering core and ligand structures,follows.Subsequently,the interaction between the core and ligand structures of Au NCs and their impact on electrocatalytic performance in diverse reactions are examined.Concluding the discourse,challenges and personal prospects are presented to guide the rational design of efficient electrocatalysts and advance electrocatalytic reactions.
基金financially supported by the National Natural Science Foundation of China(51572166,52102070)the Program for Professor of Special Appointment at Shanghai Institutions of Higher Learning(GZ2020012)+4 种基金the Key Research Project of Zhejiang Laboratory(2021PE0AC02)the China Postdoctoral Science Foundation(2021M702073)BAJC R&D Fund Projects(BA23011)Australian Research Council Future Fellowships(FT230100436)the Shanghai Technical Service Center for Advanced Ceramics Structure Design and Precision Manufacturing(20DZ2294000)。
文摘Cobalt-based electrocatalysts take advantage of potentially harmonizable microstructure and flexible coupling effects compared to commercial noble metal-based catalytic materials.However,conventional water electrolysis systems based on cobalt-based monofunctional hydrogen evolution reaction(HER)or oxygen evolution reaction(OER)catalysts have certain shortcomings in terms of resource utilization and universality.In contrast,cobalt-based bifunctional catalysts(CBCs)have attracted much attention in recent years for overall water splitting systems because of their practicality and reduced preparation cost of electrolyzer.This review aims to address the latest development in CBCs for total hydrolysis.The main modification strategies of CBCs are systematically classified in water electrolysis to provide an overview of how to regulate their morphology and electronic configuration.Then,the catalytic performance of CBCs in total-hydrolysis is summarized according to the types of cobalt-based phosphides,sulfides and oxides,and the mechanism of strengthened electrocatalytic ability is emphasized through combining experiments and theoretical calculations.Future efforts are finally suggested to focus on exploring the dynamic conversion of reaction intermediates and building near-industrial CBCs,designing advanced CBC materials through micro-modulation,and addressing commercial applications.
基金supported by the National Natural Science Foundation of China(Nos.22008058)Natural Science Foundation of Hubei Province(No.2023AFB1010,2022CFB958)+5 种基金Key Project of Scientific Plan of Education Department of Hubei Province(No.D20232501)the Natural Science Foundation of Zhejiang Province(LQ23E020002)Wenzhou Key Scientific and Technological Innovation Research Project(ZG2023053)Wenzhou Natural Science Foundation(G20220019)Cooperation between industry and education project of Ministry of Education(220601318235513)Wenzhou Science and Technology Association Serves Scientific and Technological Innovation Projects(KJFW0201).
文摘The key to obtaining high intrinsic catalytic activity of Me-N_(x)-C electrocatalysts for Zn-air batteries is to form high-density bifunctional Me-N_(x) active sites during the pyrolysis of the precursor while maintaining structural stability.In this study,a host-vip spatial confinement strategy was utilized to synthesize a composite catalyst consisting of Co_(3)Fe_(7) nanoparticles confined in an N-doped carbon network.The coupling between the host(MIL-88B)and vip(cobalt porphyrin,CoPP)produces highdensity bimetallic atomic active sites.By controlling the mass of vip molecules,it is possible to construct precursors with the highest activity potential.The Co_(3)Fe_(7)/NC material with a certain amount of the vip displays a better electrocatalytic performance for both oxygen reduction reaction and oxygen evolution reaction with a half-wave potential(E_(1/2))of 0.85 V and an overpotential of 1.59 V at 10 mAcm^(-2),respectively.The specific structure of bimetallic active centers is verified to be FeN2-CoN_(4) using experimental characterizations,and the oxygen reaction mechanism is explored by in-situ characterization techniques and first-principles calculations.The Zn-air battery assembled with Co_(3)Fe_(7)/NC cathode exhibits a remarkable open-circuit voltage of 1.52 V,an exceptional peak power density of 248.1mWcm^(-2),and stable cycling stability over 1000 h.Particularly,the corresponding flexible Zn-air battery affords prominent cycling performance under different bending angles.This study supplies the idea and method of designing catalysts with specific structures at the atomic and electronic scales for breaking through the large-scale application of electrocatalysts based on oxygen reactions in fuel cells/metal-air batteries.
基金financially supported by the National Natural Science Foundation of China(No.22008135)the China Postdoctoral Science Foundation(No.2020M670345)。
文摘Today,nanocrystals enclosed by high-index facets(HIFs)are attracting widely attentions of researchers due to their tremendous potential in the field of catalysis,especially in electrocatalysis,such as electro-oxidation of small organic molecule(such as formic acid,methanol,and ethanol),oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER).However,the practical applications of nanocrystals enclosed by HIFs still face many limitations in preparations of advanced electrocatalysts,including preparation strategy,limited life-time and stability.The development of advanced electrocatalysts enclosed with HIFs is crucial for solving these problems if the large-scale application of them is to be realized.Herein,we firstly detailedly demonstrate the identification methods of nanocrystals enclosed by HIFs,and then preparation strategies are elaborated in detail in this review.Current advanced nanocrystals enclosed by HIFs in electrocatalytic application are also summarized and we present representative achievements to further reveal the relationship of excellent electrocatalytic performance and nanocrystals with HIFs.Finally,we predict the remaining challenges and present our perspectives with regards of design strategies of improving electrocatalytic performance of Ptbased catalysts in the future.
基金financially supported by the Natural Science Foundation of Hebei Province(No.B2021208030)College Students Innovation Training Program(Nos.202206224 and S2021113409001)。
文摘Hydrogen is considered as the promising energy carrier to substitute traditional fossil fuel,due to its cleanliness,renewability and high energy density.Water electrolysis is a simple and eonvenient technology for hydrogen production.The efficiency of water electrolysis for hydrogen production is limited by the electrocatalytic performances on hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The exorbitant Pt-and Ir-/Ru-based electrocatalysts as optimal HER and OER electrocatalysts,respectively,restrict water electrolysis development.Recently,non-precious metal-based high-entropy electrocatalysts have exhibited excellent electrocatalytic activities and long-term stabilities for water electrolysis,as promising precious cataly st candidates.Therefore,the construction of the high-entropy electroc atalysts is vital to water electrolysis industry.Electrodeposition technology is an efficient method for the preparation of high-entropy electrocatalysts due to its simple,fast,energy-saving and environmental-friendly advantages.Multi-component co-precipitation facilely occurs during the electroredox in electrodeposition processes.High-entropy alloys,oxides,(oxy)hydroxides,phosphides and phosphorus sulfide oxides have been successfully prepared by galvanostatic,potentiostatic electrodeposition,cyclic voltammetry,pulse,nanodroplet-mediated and cathodic plasma electrodeposition techniques.Hence,introduction of the development of high-entropy electrocatalysts synthesized by electrodeposition technology is significant to researchers and industries.Challenges and outlooks are also concluded to boost the industrial application of electrodeposition in water electrolysis and other energy conversion areas.
基金financially supported by the National Key Research and Development Program(2018YFB1502503)the Sichuan Science and Technology Program(2020YJ0299)financial supports from the Australian Research Council under the future fellowship scheme(FT160100107)。
文摘Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes.High-temperature pyrolysis(>500°C)methods are used to control their crystalline orderings,critical to their electrocatalytic activity and durability.However,the high temperature would cause severe aggregation,resulting in a low catalytic active surface area.Significant research efforts have been devoted to addressing this issue.This short review summarizes recent research progress on synthesizing noble metal-based intermetallic electrocatalysts by space-confined pyrolysis.We focus on three strategies:isolation in pores,coverture by shells,and immobilization by salts.The advantages and existing problems of different methods are highlighted.Last,important issues to be addressed in future research are also discussed.We hope that this article will stimulate future research to develop high-performance intermetallic catalysts for practical applications.
基金supported by the National Natural Science Foundation of China(52373114,52073092,22231007,22001071)。
文摘Imparting one-dimensional(1D)ultrafine organic nanowires with tailored ligands and atomically-dispersed central noble metal to craft high-performance hybrid single atom electrocatalysts offers a prospective yet challenging approach for the advancement in hydrogen evolution reactions(HER).Herein,we report the evaporation-induced self-assembly of sequence-defined amphiphilic alternating azopeptoids(AAAPs)to generate photo-responsive and micron-scale ultrafine peptoid nanowires(UFPNWs)with a diameter of~1.8 nm via pendants'hydrophobic conjugate stacking mechanism,exemplifying the finest biomimetic polymers-based nanowires to date.A series of 1D UFPNWs-based single-atom catalysts(SACs)were meticulously fabricated using the chelation interaction between Pt ions and nitrogenous ligands.The photo-controllable electrocatalytic performance was evaluated toward acidic HER,which was highly dependent on the presence of Pt elements,the structural characteristic of supports,and the peripheral coordination microenvironment of the center Pt atoms.Notably,the Pt-based hybrid SACs using terpyridine-modified UFPNWs as support presented favorable electrocatalytic capacity with an overpotential of~20 m V at a current density of 10 m A cm^(-2),and a mass activity of 89.6 times greater than commercial Pt/C catalyst.Our work paves an appealing avenue for the construction of stimuli-responsive 1D organic nanowire-based hybrid catalysts with controllable electrocatalytic HER performance.
基金The funding has been received from Fundamental Research Funds for the Central Universities with Grant no.2232021A-02Shanghai Committee of Science and Technology,China with Grant No.21ZR1480000National Natural Science Foundation of China with Grant Nos.52122312,52172291.
文摘Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considerable research efforts have been devoted to construct advanced fiber materials possessing conductive network(to facilitate efficient electron transport)and large specific surface area(to support massive catalytically active sites)to boost electrocatalysis performance.Herein,we focused on recent advances in fiber-based electrocatalyst with enhanced electrocatalytic activity.Moreover,the synthesis,structure,and properties of fiber materials and their applications in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,carbon dioxide reduction reaction,and nitrogen reduction reaction are discussed.Finally,the research challenges and future prospects of fiber materials in electrocatalysis applications are proposed.
