Optimizing the microdynamics in alkaline and neutral conditions is a significant but challenging task in developing pH-universal hydrogen evolution(HER)electrocatalysts.Herein,a unique Pt-O-Ni bridge has been construc...Optimizing the microdynamics in alkaline and neutral conditions is a significant but challenging task in developing pH-universal hydrogen evolution(HER)electrocatalysts.Herein,a unique Pt-O-Ni bridge has been constructed to alter the coordination and electronic environment between Pt nanoparticles(Pt_n)and nickel metaphosphate(NPO)substrate(Pt-NPO).Sufficient electron transfer from NPO to Pt_n to maintain an electron-rich environment and a low valence state of Pt_n.Furthermore,H*is produced from the H_(2)O dissociation on Ni site and then spillover toward Pt sites to bind into H_(2),which makes up for the insufficient H_(2)O dissociation ability of Pt in Volmer step.Pt-NPO exhibits long-term stability and only need the overpotentials of 22.3,33.0 and 30.5 mV to attain 10 mA cm^(-2)in alkaline,neutral and acidic media,respectively.The anion-exchange membrane(AEM)water electrolyzer catalyzed by Pt-NPO shows high water electrolysis performance that a cell voltage of 1.73 V is needed to obtain the current density of500 mA cm^(-2)in 1 M KOH at 80℃,at the same time maintains good stability for 350 h.The regulation strategy proposed in this work is helpful for the design and synthesis of highly efficient pH-universal HER electrocatalysts.展开更多
Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic ...Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic for catalyst synthesis.Employing pre-trapping and post-activation strategy,Fe-N bonding structure and S,Se functionalized heteroatom are integrated into a conductive porous carbon.In this process,the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene(Tf-TAPA)adsorbs Fe^(3+)under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles longchain thiophene-S.Subsequently,the Fe^(3+)is transformed into Fe-N_(x)moieties with the conversion of the organic chain to incompletely graphitized carbon.Furthermore,the alteration of the electronic configuration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic efficiency.Benefitting from the Fe-N_(x)bonding structure,dense structural defects,and conductive carbon networks,the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90%current retention rate,outstripping the Pt/C benchmark.Moreover,the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 m W/cm^(2),respectively.This study provides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst.展开更多
It is commonly known that the performance of electrocatalysts is largely influenced by the size,morphology,composition,and crystalline phase of noble metal nanocrystals.However,the limited reserves and high cost of no...It is commonly known that the performance of electrocatalysts is largely influenced by the size,morphology,composition,and crystalline phase of noble metal nanocrystals.However,the limited reserves and high cost of noble metals largely restrict their industrial applications.Along with the development of characterization techniques,theoretical calculations,and advanced material synthesis methods,modulating the electrocatalytic properties of noble metal nanocrystals at the atomic scale(e.g.,monolayer/sub-monolayer,single-atom alloy,ultrafine structure)has been flooding out.Engineering noble metal nanocrystals at the atomic level could not only immensely improve the noble metal atom utilization efficiency and lower the cost,but also boost the catalytic performance.In this review,we summarize the recent advanced progresses of regulating the noble metal nanocrystals at the atomic scale towards energy conversion application.Then,the challenges and perspectives of designing noble metal nanocrystals at the atomic scale in the future are discussed and considered.It is expected that this review will inspire scientists to further study precious metal-based materials for energy-oriented catalysis.展开更多
Developing high performance and low-cost catalysts for oxygen reduction reaction(ORR)in challenging acid condition is vital for proton-exchange-membrane fuel cells(PEMFCs).Carbon-supported nonprecious metal single ato...Developing high performance and low-cost catalysts for oxygen reduction reaction(ORR)in challenging acid condition is vital for proton-exchange-membrane fuel cells(PEMFCs).Carbon-supported nonprecious metal single atom catalysts(SACs)have been identified as potential catalysts in the field.Great advance has been obtained in constructing diverse active sites of SACs for improving the performance and understanding the fundamental principles of regulating acid ORR performance.However,the ORR performance of SACs is still unsatisfactory.Importantly,microenvironment adjustment of SACs offers chance to promote the performance of acid ORR.In this review,acid ORR mechanism,attenuation mechanism and performance improvement strategies of SACs are presented.The strategies for promoting ORR activity of SACs include the adjustment of center metal and its microenvironment.The relationship of ORR performance and structure is discussed with the help of advanced experimental investigations and theoretical calculations,which will offer helpful direction for designing advanced SACs for ORR.展开更多
By incorporating a limited number of precious metal atoms into the base metal,the single-atom alloy catalyst not only optimizes the electronic structure and stability of the catalyst but also emerges as an innovative ...By incorporating a limited number of precious metal atoms into the base metal,the single-atom alloy catalyst not only optimizes the electronic structure and stability of the catalyst but also emerges as an innovative material that enhances the efficiency and selectivity of catalytic reactions.RuCo single-atom alloy electrocatalyst supported on S,N co-doped carbon nanosheets(RuCo SAA/SNC)uniformly distributed on nitrogen,sulfur co-doped carbon nanosheets was prepared by two-step pyrolysis and carbonization.The incorporation of Ru not only optimizes the atomic utilization of Ru but also enhances the charge conduction properties of the surface Co species,thereby increasing the evolution and migration rates of hydrogen ions.In a 0.5 M H_(2)SO_(4) solution,the RuCo SAA/SNC catalyst demonstrates a tafel slope of 27.5 mV·dec^(-1) and an overpotential of merely 43 mV at 10 mA·cm^(-2).This work achieves enhanced catalytic performance and stability by precisely regulating the atomic-level structure of single-atom alloy catalysts,thereby promoting their widespread application in energy conversion and green chemistry.展开更多
Single atom catalysts(SACs)have attracted great attention,yet the quest for highly-efficient catalysts is driven by the current obstacles of ambiguous structure-performance relationship.Here,we report a nature keratin...Single atom catalysts(SACs)have attracted great attention,yet the quest for highly-efficient catalysts is driven by the current obstacles of ambiguous structure-performance relationship.Here,we report a nature keratin-based Fe-S_(1)N_(3)SACs with ultrathin two-dimensional(2D)porous carbon nanosheets structure,by controlling the active center through the precise coordination of sulfur and nitrogen.Compared with natural silk-based Fe-N_(4) catalyst,the Fe-S_(1)N_(3)SACs exhibit excellent Fenton-like oxidation degradation ability.X-ray absorption fine structure(XAFS)and electron paramagnetic resonance(EPR)results confirm that S doping is conducive to electron transfer,to accurately generate·OH with high oxidative degradation capacity at the active site.Therefore,the optimized Fe-S_(1)N_(3)catalyst showed higher oxidation degradation activity for organic pollutant substrates(methylene blue(MB),Rhodamine B(RhB)and phenol),significantly superior to Fe-N_(4) samples.This work is devoted to the treatment and application of natural fibers,which provides a novel method for the synthesis of SACs and the regulation of atomic coordination environment.展开更多
Single atom catalysts(SACs)play a crucial role in energy catalysis due to their distinct coordination environment and high atomic utilization efficiency.This study focuses on the synthesis of a monatomic Cu catalyst w...Single atom catalysts(SACs)play a crucial role in energy catalysis due to their distinct coordination environment and high atomic utilization efficiency.This study focuses on the synthesis of a monatomic Cu catalyst with Cu-N1C1 coordination anchored to N-doped Ti_(3)C_(2)T_(x) MXene(Cu SA@N-Ti_(3)C_(2)T_(x))to achieve efficient reduction of CO_(2) to CO.Detailed characterization,including morphology and multispectral analysis,confirmed the uniform distribution of asymmetrically coordinated Cu atoms in unsaturated C-Cu-N bridge fragments on Ti_(3)C_(2)T_(x).The Cu SA@N-Ti_(3)C_(2)T_(x) catalyst exhibited an excellent CO selectivity with Faraday efficiency of 97.4%at-0.58 V vs.reversible hydrogen electrode(RHE)and satisfactory durability.The in situ X-ray absorption fine structure(XAFS)results confirmed that the carbon dioxide reduction reaction(CO_(2)RR)product distribution is mainly affected by potential-dependent valence change of Cu species.These findings highlight the extensive potential of tuning coordination structure of MXene-based single-atom catalysts for CO_(2) reduction reactions.展开更多
As an alternative energy,hydrogen can be converted into electrical energy via direct electrochemical conversion in fuel cells.One important drawback of full cells is the sluggish oxygen reduction reaction(ORR)promoted...As an alternative energy,hydrogen can be converted into electrical energy via direct electrochemical conversion in fuel cells.One important drawback of full cells is the sluggish oxygen reduction reaction(ORR)promoted by the high-loading of platinum-group-metal(PGM)electrocatalysts.Fe-N-C family has been received extensive attention because of its low cost,long service life and high oxygen reduction reaction activity in recent years.In order to further enhance the ORR activity,the synthesis method,morphology regulation and catalytic mechanism of the active sites in Fe-N-C catalysts are investigated.This paper reviews the research progress of Fe-N-C from nanoparticles to single atoms.The structure-activity relationship and catalytic mechanism of the catalyst are studied and discussed,which provide a guidance for rational design of the catalyst,so as to promote the more reasonable design of Fe-N-C materials.展开更多
基金supported by the National Natural Science Foundation of China(22202080,22034006 and 22393930)Jilin Talent Development Foundation(E41S2001)the National Key Research and Development Program of China(2022YFF0710000).
文摘Optimizing the microdynamics in alkaline and neutral conditions is a significant but challenging task in developing pH-universal hydrogen evolution(HER)electrocatalysts.Herein,a unique Pt-O-Ni bridge has been constructed to alter the coordination and electronic environment between Pt nanoparticles(Pt_n)and nickel metaphosphate(NPO)substrate(Pt-NPO).Sufficient electron transfer from NPO to Pt_n to maintain an electron-rich environment and a low valence state of Pt_n.Furthermore,H*is produced from the H_(2)O dissociation on Ni site and then spillover toward Pt sites to bind into H_(2),which makes up for the insufficient H_(2)O dissociation ability of Pt in Volmer step.Pt-NPO exhibits long-term stability and only need the overpotentials of 22.3,33.0 and 30.5 mV to attain 10 mA cm^(-2)in alkaline,neutral and acidic media,respectively.The anion-exchange membrane(AEM)water electrolyzer catalyzed by Pt-NPO shows high water electrolysis performance that a cell voltage of 1.73 V is needed to obtain the current density of500 mA cm^(-2)in 1 M KOH at 80℃,at the same time maintains good stability for 350 h.The regulation strategy proposed in this work is helpful for the design and synthesis of highly efficient pH-universal HER electrocatalysts.
基金supported by Distinguished Young Scholar Fund Project of Hunan Province Natural Science Foundation(No.2023JJ10041)the Hunan Provincial Education Office Foundation of China(No.21B0147)+3 种基金the Science and Technology Program of Xiangtan(No.GX-ZD20211004)the Hunan Provincial united foundation(No.2022JJ50136)the National Natural Science Foundation of China(No.52003230)the Science and Technology Innovation Program of Hunan Province(No.2021RC2091)。
文摘Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic for catalyst synthesis.Employing pre-trapping and post-activation strategy,Fe-N bonding structure and S,Se functionalized heteroatom are integrated into a conductive porous carbon.In this process,the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene(Tf-TAPA)adsorbs Fe^(3+)under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles longchain thiophene-S.Subsequently,the Fe^(3+)is transformed into Fe-N_(x)moieties with the conversion of the organic chain to incompletely graphitized carbon.Furthermore,the alteration of the electronic configuration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic efficiency.Benefitting from the Fe-N_(x)bonding structure,dense structural defects,and conductive carbon networks,the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90%current retention rate,outstripping the Pt/C benchmark.Moreover,the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 m W/cm^(2),respectively.This study provides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst.
基金supported by the National Key R&D Program of China 2017YFA(0208300,0700104)the National Natural Science Foundation of China(21522107,21671180)+1 种基金the DNL Cooperation Fund,CAS(NDL201918)the China Postdoctoral Science Foundation(2019TQ0295,2019M662165)。
文摘It is commonly known that the performance of electrocatalysts is largely influenced by the size,morphology,composition,and crystalline phase of noble metal nanocrystals.However,the limited reserves and high cost of noble metals largely restrict their industrial applications.Along with the development of characterization techniques,theoretical calculations,and advanced material synthesis methods,modulating the electrocatalytic properties of noble metal nanocrystals at the atomic scale(e.g.,monolayer/sub-monolayer,single-atom alloy,ultrafine structure)has been flooding out.Engineering noble metal nanocrystals at the atomic level could not only immensely improve the noble metal atom utilization efficiency and lower the cost,but also boost the catalytic performance.In this review,we summarize the recent advanced progresses of regulating the noble metal nanocrystals at the atomic scale towards energy conversion application.Then,the challenges and perspectives of designing noble metal nanocrystals at the atomic scale in the future are discussed and considered.It is expected that this review will inspire scientists to further study precious metal-based materials for energy-oriented catalysis.
基金supported by the Joint Funds of the National Natural Science Foundation of China(U20A20280)the Postgraduate Scientific Research Innovation Project of Hunan Province(CX20210171)。
文摘Developing high performance and low-cost catalysts for oxygen reduction reaction(ORR)in challenging acid condition is vital for proton-exchange-membrane fuel cells(PEMFCs).Carbon-supported nonprecious metal single atom catalysts(SACs)have been identified as potential catalysts in the field.Great advance has been obtained in constructing diverse active sites of SACs for improving the performance and understanding the fundamental principles of regulating acid ORR performance.However,the ORR performance of SACs is still unsatisfactory.Importantly,microenvironment adjustment of SACs offers chance to promote the performance of acid ORR.In this review,acid ORR mechanism,attenuation mechanism and performance improvement strategies of SACs are presented.The strategies for promoting ORR activity of SACs include the adjustment of center metal and its microenvironment.The relationship of ORR performance and structure is discussed with the help of advanced experimental investigations and theoretical calculations,which will offer helpful direction for designing advanced SACs for ORR.
基金supported by the National Natural Science Foundation of China(No.22201262).
文摘By incorporating a limited number of precious metal atoms into the base metal,the single-atom alloy catalyst not only optimizes the electronic structure and stability of the catalyst but also emerges as an innovative material that enhances the efficiency and selectivity of catalytic reactions.RuCo single-atom alloy electrocatalyst supported on S,N co-doped carbon nanosheets(RuCo SAA/SNC)uniformly distributed on nitrogen,sulfur co-doped carbon nanosheets was prepared by two-step pyrolysis and carbonization.The incorporation of Ru not only optimizes the atomic utilization of Ru but also enhances the charge conduction properties of the surface Co species,thereby increasing the evolution and migration rates of hydrogen ions.In a 0.5 M H_(2)SO_(4) solution,the RuCo SAA/SNC catalyst demonstrates a tafel slope of 27.5 mV·dec^(-1) and an overpotential of merely 43 mV at 10 mA·cm^(-2).This work achieves enhanced catalytic performance and stability by precisely regulating the atomic-level structure of single-atom alloy catalysts,thereby promoting their widespread application in energy conversion and green chemistry.
基金This work was supported by the Beijing Natural Science Foundation(No.2212018)the National Natural Science Foundation of China(No.22105116)+2 种基金Natural Science Foundation of Hebei Province(No.B2021208001)Key Research and Development Program of Shijiazhuang(No.221070361A)the Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘Single atom catalysts(SACs)have attracted great attention,yet the quest for highly-efficient catalysts is driven by the current obstacles of ambiguous structure-performance relationship.Here,we report a nature keratin-based Fe-S_(1)N_(3)SACs with ultrathin two-dimensional(2D)porous carbon nanosheets structure,by controlling the active center through the precise coordination of sulfur and nitrogen.Compared with natural silk-based Fe-N_(4) catalyst,the Fe-S_(1)N_(3)SACs exhibit excellent Fenton-like oxidation degradation ability.X-ray absorption fine structure(XAFS)and electron paramagnetic resonance(EPR)results confirm that S doping is conducive to electron transfer,to accurately generate·OH with high oxidative degradation capacity at the active site.Therefore,the optimized Fe-S_(1)N_(3)catalyst showed higher oxidation degradation activity for organic pollutant substrates(methylene blue(MB),Rhodamine B(RhB)and phenol),significantly superior to Fe-N_(4) samples.This work is devoted to the treatment and application of natural fibers,which provides a novel method for the synthesis of SACs and the regulation of atomic coordination environment.
基金supported by the Open Research Fund of State Environmental Protection Key Laboratory of Eco-industry,Chinese Research Academy of Environmental Sciences(No.2022KFF-07)the National Natural Science Foundation of China(Nos.22201262,52302092,22375019)+2 种基金Natural Science Foundation of Henan Province(No.222300420290)Fundamental Research Funds for the Central Universities(No.2023MS057)Beijing Institute of Technology Research Fund Program for Young Scholars(No.2022CX01011).
文摘Single atom catalysts(SACs)play a crucial role in energy catalysis due to their distinct coordination environment and high atomic utilization efficiency.This study focuses on the synthesis of a monatomic Cu catalyst with Cu-N1C1 coordination anchored to N-doped Ti_(3)C_(2)T_(x) MXene(Cu SA@N-Ti_(3)C_(2)T_(x))to achieve efficient reduction of CO_(2) to CO.Detailed characterization,including morphology and multispectral analysis,confirmed the uniform distribution of asymmetrically coordinated Cu atoms in unsaturated C-Cu-N bridge fragments on Ti_(3)C_(2)T_(x).The Cu SA@N-Ti_(3)C_(2)T_(x) catalyst exhibited an excellent CO selectivity with Faraday efficiency of 97.4%at-0.58 V vs.reversible hydrogen electrode(RHE)and satisfactory durability.The in situ X-ray absorption fine structure(XAFS)results confirmed that the carbon dioxide reduction reaction(CO_(2)RR)product distribution is mainly affected by potential-dependent valence change of Cu species.These findings highlight the extensive potential of tuning coordination structure of MXene-based single-atom catalysts for CO_(2) reduction reactions.
基金W.X.C.acknowledges the National Natural Science Foundation of China(No.21801015)W.X.C.acknowledges the Beijing Institute of Technology Research Fund Program for Young Scholars(No.3090012221909).
文摘As an alternative energy,hydrogen can be converted into electrical energy via direct electrochemical conversion in fuel cells.One important drawback of full cells is the sluggish oxygen reduction reaction(ORR)promoted by the high-loading of platinum-group-metal(PGM)electrocatalysts.Fe-N-C family has been received extensive attention because of its low cost,long service life and high oxygen reduction reaction activity in recent years.In order to further enhance the ORR activity,the synthesis method,morphology regulation and catalytic mechanism of the active sites in Fe-N-C catalysts are investigated.This paper reviews the research progress of Fe-N-C from nanoparticles to single atoms.The structure-activity relationship and catalytic mechanism of the catalyst are studied and discussed,which provide a guidance for rational design of the catalyst,so as to promote the more reasonable design of Fe-N-C materials.
