Hydrogen production from water splitting using renewable electric energy is an interesting topic towards the carbon neutral future.Single atom catalysts(SACs)have emerged as a new frontier in the field of catalysis su...Hydrogen production from water splitting using renewable electric energy is an interesting topic towards the carbon neutral future.Single atom catalysts(SACs)have emerged as a new frontier in the field of catalysis such as hydrogen evolution reaction(HER),owing to their intriguing properties like high activity and excellent chemical selectivity.The catalytic active moiety is often comprised of a single metal atom and its neighboring environment from the supports.Recent published reviews about electricdriven HER tend to classify these SACs by the species of active center atom,nevertheless the influence of their neighboring coordinated atoms from the supports is somehow neglected.Thus we classify the SACs for HER through the type of supports,highlighting the electronic metal–support interaction and their coordination environment from support.Then,we put forward some structural designing strategies including regulating of the central atoms,coordination environments,and metal-support interactions.Finally,the current challenges and future research perspectives of SACs for HER are briefly proposed.展开更多
A novel coordination polymer, [Fe(C 5H 4NCOO) 2] n, was synthesized by hydrothermal reaction and characterized by elemental analysis as well as IR spectroscopy. The crystal structure (with a novel 3-D network) of this...A novel coordination polymer, [Fe(C 5H 4NCOO) 2] n, was synthesized by hydrothermal reaction and characterized by elemental analysis as well as IR spectroscopy. The crystal structure (with a novel 3-D network) of this compound belongs to monoclinic, space group P2 1/n, a=0.49544(1) nm, b=1.32443(2) nm, c=1.04983(1) nm, β=101.586(1)°. The diffuse reflectance spectra (200～2500 nm) showed that the polymer had strong absorbance in 375～563 nm (E g≈2.5 eV) region and weak absorbance from 720 to 2500 nm (near infrared spectra).展开更多
Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction(ORR)kinetics with high atom economy,owing to remarkable attributes including nearly 100%atomic utiliz...Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction(ORR)kinetics with high atom economy,owing to remarkable attributes including nearly 100%atomic utilization and exceptional catalytic functionality.Furthermore,accurately controlling atomic physical properties including spin,charge,orbital,and lattice degrees of atomically dispersed catalysts can realize the optimized chemical properties including maximum atom utilization efficiency,homogenous active centers,and satisfactory catalytic performance,but remains elusive.Here,through physical and chemical insight,we review and systematically summarize the strategies to optimize atomically dispersed ORR catalysts including adjusting the atomic coordination environment,adjacent electronic orbital and site density,and the choice of dual-atom sites.Then the emphasis is on the fundamental understanding of the correlation between the physical property and the catalytic behavior for atomically dispersed catalysts.Finally,an overview of the existing challenges and prospects to illustrate the current obstacles and potential opportunities for the advancement of atomically dispersed catalysts in the realm of electrocatalytic reactions is offered.展开更多
Fe-N-C catalysts represent very promising cathode catalysts for polymer electrolyte fuel cells,owing to their outstanding activity for the oxygen reduction reaction(ORR),especially in alkaline media.In this review,we ...Fe-N-C catalysts represent very promising cathode catalysts for polymer electrolyte fuel cells,owing to their outstanding activity for the oxygen reduction reaction(ORR),especially in alkaline media.In this review,we summarize recent advances in the design and synthesis of Fe-N-C catalysts rich in highly dispersed FeNx active sites.Special emphasis is placed on emerging strategies for tuning the electronic structure of the Fe atoms to enhance the ORR activity,and also maximizing the surface concentration of FeNx sites that are catalytically accessible during ORR.While great progress has been made over the past 5 years in the development of Fe-N-C catalyst for ORR,significant technical obstacles still need to be overcome to enable the large-scale application of Fe-N-C materials as cathode catalysts in real-world fuel cells.展开更多
Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental protection.Here,we report an efficient NitRR catalyst composed of single Mn sites...Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental protection.Here,we report an efficient NitRR catalyst composed of single Mn sites with atomically dispersed oxygen(O)coordination on bacterial cellulose-converted graphitic carbon(Mn-O-C).Evidence of the atomically dispersed Mn-(O-C_(2))_(4)moieties embedding in the exposed basal plane of carbon surface is confirmed by X-ray absorption spectroscopy.As a result,the as-synthesized Mn-O-C catalyst exhibits superior NitRR activity with an NH_(3)yield rate(RNH_(3))of 1476.9±62.6μg h^(−1)cm^(−2)at−0.7 V(vs.reversible hydrogen electrode,RHE)and a faradaic efficiency(FE)of 89.0±3.8%at−0.5 V(vs.RHE)under ambient conditions.Further,when evaluated with a practical flow cell,Mn-O-C shows a high RNH_(3)of 3706.7±552.0μg h^(−1)cm^(−2)at a current density of 100 mA cm−2,2.5 times of that in the H cell.The in situ FT-IR and Raman spectroscopic studies combined with theoretical calculations indicate that the Mn-(O-C_(2))_(4)sites not only effectively inhibit the competitive hydrogen evolution reaction,but also greatly promote the adsorption and activation of nitrate(NO_(3)^(−)),thus boosting both the FE and selectivity of NH_(3)over Mn-(O-C_(2))_(4)sites.展开更多
Emerging as a prominent area of focus in energy conversion and storage technologies,the development of highly active metal-based single-atom catalysts(SACs)holds great significance in searching alternatives to replace ...Emerging as a prominent area of focus in energy conversion and storage technologies,the development of highly active metal-based single-atom catalysts(SACs)holds great significance in searching alternatives to replace precious metals toward the efficient,stable,and low-cost hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).Combining the tremendous tunability of ligand and coordination environment with rich metal-based electrocatalysts can create breakthrough opportunities for achieving both high stability and activity.Herein,we propose a novel and stable holey graphene-like carbon nitride monolayer g-C_(16)N5(N_(4)@g-C_(16)N_(3))stoichiometries interestingly behaving as a natural substrate for constructing SACs((TM-N_(4))@g-C_(16)N_(3)),whose evenly distributed holes map rich and uniform nitrogen coordination positions with electron-rich lone pairs for anchoring transition metal(TM)atoms.Then,we employed density functional theory(DFT)calculations to systematically investigate the electrocatalytic activity of(TM-N_(4))@g-C_(16)N_(3) toward HER/OER/ORR,meanwhile considering the synergistic modulation of H-loading and O-coordination((TM-N_(x)O_(4-x))@g-C_(16)N_(3)^(-)H_(3),x=0–4).Together a“four-step procedure”screening mechanism with the first-principles high-throughput calculations,we find that(Rh-N_(4))and(Ir-N_(2)O_(2)-II)distributed on g-C_(16)N_(3)^(-)H_(3) can modulate the adsorption strength of the adsorbates,thus achieving the best HER/OER/ORR performance among 216 candidates,and the lowest overpotential of 0.098/0.3/0.46 V and 0.06/0.48/0.45 V,respectively.Additionally,the d-band center,crystal orbital Hamilton population(COHP),and molecular orbitals are used to reveal the OER/ORR activity source.Particularly,the Rh/Ir-d orbital is dramatically hybridized with the O-p orbital of the oxygenated adsorbates,so that the lone-electrons incipiently locate at the antibonding orbital pair up and populate the downward bonding orbital,allowing展开更多
Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to...Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to single-crystal(SC-SC) transformation as new method for the direct observation of host-guest chemistry,can reveal the intrinsic relevance and interaction between the framework and guest molecules.This review describes our work concerning PCPs and recent investigations of others,within the last four years,from the viewpoint of crystalline-state transformations of PCPs on guest removal or inclusion processes.Ligand substitution reaction and postsynthetic modification of PCPs in SC-SC fashion which were distinguished from conventional crystalline-state transformation triggered by guest removal or exchange were highlighted in this review.The research status of crystalline-state transformation in China was briefly introduced as well.Series of structure analysis techniques including single-crystal X-ray diffraction,powder X-ray diffraction,neutron diffraction,inelastic neutron scattering as well as the application of synchrotron radiation light source will inevitably promote the advance of study of crystalline-state transformation.And as a hotspot,deep investigations of crystalline-state transformation also help us to overcome the challenge of achieving multifunction and the correlation among them,such as sorption,magnetism,optical or electrical properties simultaneously in PCPs and contribute to design stimulate-oriented porous intelligent materials in the future.展开更多
Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral tec...Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral techniques, and Rose-Dragomethod. Electronic effects in metalloporphrins and effects of ligands, temperature andsolvents were investigated. It was found that equilibrium constants for reactions of ZnT(p-X)PP with ligands follow Hammett equation. The changes of standard molar enthalpy△rHm and the changes of standard molar entropy △rSm of the reactions were obtainedfrom the plots of lnK vs. 1/T.展开更多
Developing transition metal-nitrogen-carbon materials(M-N-C)as electrocatalysts for the oxygen evolution reaction(OER)is significant for low-cost energy conversion systems.Further d-orbital adjustment of M center in M...Developing transition metal-nitrogen-carbon materials(M-N-C)as electrocatalysts for the oxygen evolution reaction(OER)is significant for low-cost energy conversion systems.Further d-orbital adjustment of M center in M-N-C is beneficial to the improvement of OER performance.Herein,we synthesize a single-Mn-atom catalyst based on carbon skeleton(Mn_(1)-N_(2)S_(2)C_(x))with isolated Mn-N_(2)S_(2)sites,which exhibits high alkaline OER activity(η10=280 mV),low Tafel slope(44 mV·dec^(−1)),and excellent stability.Theoretical calculations reveal the pivotal function of isolated Mn-N_(2)S_(2)sites in promoting OER,including the adsorption kinetics of intermediates and activation mechanism of active sites.The doping of S causes the increase in both charge density and work function of active Mn center,and ortho-Mn_(1)-N_(2)S_(2)C_(x)expresses the fastest OER kinetics due to the asymmetric plane.展开更多
基金the National Key Research and Development Program of China(No.2018YFA0702003)the National Natural Science Foundation of China(Nos.21890383 and 21871159)+1 种基金the Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)China Postdoctoral Science Foundation(2021M691834).
文摘Hydrogen production from water splitting using renewable electric energy is an interesting topic towards the carbon neutral future.Single atom catalysts(SACs)have emerged as a new frontier in the field of catalysis such as hydrogen evolution reaction(HER),owing to their intriguing properties like high activity and excellent chemical selectivity.The catalytic active moiety is often comprised of a single metal atom and its neighboring environment from the supports.Recent published reviews about electricdriven HER tend to classify these SACs by the species of active center atom,nevertheless the influence of their neighboring coordinated atoms from the supports is somehow neglected.Thus we classify the SACs for HER through the type of supports,highlighting the electronic metal–support interaction and their coordination environment from support.Then,we put forward some structural designing strategies including regulating of the central atoms,coordination environments,and metal-support interactions.Finally,the current challenges and future research perspectives of SACs for HER are briefly proposed.
文摘A novel coordination polymer, [Fe(C 5H 4NCOO) 2] n, was synthesized by hydrothermal reaction and characterized by elemental analysis as well as IR spectroscopy. The crystal structure (with a novel 3-D network) of this compound belongs to monoclinic, space group P2 1/n, a=0.49544(1) nm, b=1.32443(2) nm, c=1.04983(1) nm, β=101.586(1)°. The diffuse reflectance spectra (200～2500 nm) showed that the polymer had strong absorbance in 375～563 nm (E g≈2.5 eV) region and weak absorbance from 720 to 2500 nm (near infrared spectra).
基金supported by the National Natural Science Foundation of China(22234005,21974070)the Natural Science Foundation of Jiangsu Province(BK20222015)。
文摘Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction(ORR)kinetics with high atom economy,owing to remarkable attributes including nearly 100%atomic utilization and exceptional catalytic functionality.Furthermore,accurately controlling atomic physical properties including spin,charge,orbital,and lattice degrees of atomically dispersed catalysts can realize the optimized chemical properties including maximum atom utilization efficiency,homogenous active centers,and satisfactory catalytic performance,but remains elusive.Here,through physical and chemical insight,we review and systematically summarize the strategies to optimize atomically dispersed ORR catalysts including adjusting the atomic coordination environment,adjacent electronic orbital and site density,and the choice of dual-atom sites.Then the emphasis is on the fundamental understanding of the correlation between the physical property and the catalytic behavior for atomically dispersed catalysts.Finally,an overview of the existing challenges and prospects to illustrate the current obstacles and potential opportunities for the advancement of atomically dispersed catalysts in the realm of electrocatalytic reactions is offered.
基金support from the Ministry of Business,Innovation and Employment for a Catalyst Fund grant(MAUX 1609)the University of Auckland Faculty Research Development Fund,the MacDiarmid Institute for Advanced Materials and Nanotechnology,and a generous Philanthropic donation from Greg and Kathryn Trounson.The authors are also grateful for financial support from the National Key Projects for Fundamental Research and Development of China(2017YFA0206904,2017YFA0206900)+1 种基金the National Natural Science Foundation of China(51825205,51772305,21871279)the Beijing Natural Science Foundation(2191002).
文摘Fe-N-C catalysts represent very promising cathode catalysts for polymer electrolyte fuel cells,owing to their outstanding activity for the oxygen reduction reaction(ORR),especially in alkaline media.In this review,we summarize recent advances in the design and synthesis of Fe-N-C catalysts rich in highly dispersed FeNx active sites.Special emphasis is placed on emerging strategies for tuning the electronic structure of the Fe atoms to enhance the ORR activity,and also maximizing the surface concentration of FeNx sites that are catalytically accessible during ORR.While great progress has been made over the past 5 years in the development of Fe-N-C catalyst for ORR,significant technical obstacles still need to be overcome to enable the large-scale application of Fe-N-C materials as cathode catalysts in real-world fuel cells.
基金the financial support from the Natural Science Foundation of China(Grant No.52172106)Anhui Provincial Natural Science Foundation(Grant Nos.2108085QB60 and 2108085QB61)China Postdoctoral Science Foundation(Grant Nos.2020M682057 and 2023T160651).
文摘Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental protection.Here,we report an efficient NitRR catalyst composed of single Mn sites with atomically dispersed oxygen(O)coordination on bacterial cellulose-converted graphitic carbon(Mn-O-C).Evidence of the atomically dispersed Mn-(O-C_(2))_(4)moieties embedding in the exposed basal plane of carbon surface is confirmed by X-ray absorption spectroscopy.As a result,the as-synthesized Mn-O-C catalyst exhibits superior NitRR activity with an NH_(3)yield rate(RNH_(3))of 1476.9±62.6μg h^(−1)cm^(−2)at−0.7 V(vs.reversible hydrogen electrode,RHE)and a faradaic efficiency(FE)of 89.0±3.8%at−0.5 V(vs.RHE)under ambient conditions.Further,when evaluated with a practical flow cell,Mn-O-C shows a high RNH_(3)of 3706.7±552.0μg h^(−1)cm^(−2)at a current density of 100 mA cm−2,2.5 times of that in the H cell.The in situ FT-IR and Raman spectroscopic studies combined with theoretical calculations indicate that the Mn-(O-C_(2))_(4)sites not only effectively inhibit the competitive hydrogen evolution reaction,but also greatly promote the adsorption and activation of nitrate(NO_(3)^(−)),thus boosting both the FE and selectivity of NH_(3)over Mn-(O-C_(2))_(4)sites.
基金supported by the National Natural Science Foundation of China(No.21905175).
文摘Emerging as a prominent area of focus in energy conversion and storage technologies,the development of highly active metal-based single-atom catalysts(SACs)holds great significance in searching alternatives to replace precious metals toward the efficient,stable,and low-cost hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).Combining the tremendous tunability of ligand and coordination environment with rich metal-based electrocatalysts can create breakthrough opportunities for achieving both high stability and activity.Herein,we propose a novel and stable holey graphene-like carbon nitride monolayer g-C_(16)N5(N_(4)@g-C_(16)N_(3))stoichiometries interestingly behaving as a natural substrate for constructing SACs((TM-N_(4))@g-C_(16)N_(3)),whose evenly distributed holes map rich and uniform nitrogen coordination positions with electron-rich lone pairs for anchoring transition metal(TM)atoms.Then,we employed density functional theory(DFT)calculations to systematically investigate the electrocatalytic activity of(TM-N_(4))@g-C_(16)N_(3) toward HER/OER/ORR,meanwhile considering the synergistic modulation of H-loading and O-coordination((TM-N_(x)O_(4-x))@g-C_(16)N_(3)^(-)H_(3),x=0–4).Together a“four-step procedure”screening mechanism with the first-principles high-throughput calculations,we find that(Rh-N_(4))and(Ir-N_(2)O_(2)-II)distributed on g-C_(16)N_(3)^(-)H_(3) can modulate the adsorption strength of the adsorbates,thus achieving the best HER/OER/ORR performance among 216 candidates,and the lowest overpotential of 0.098/0.3/0.46 V and 0.06/0.48/0.45 V,respectively.Additionally,the d-band center,crystal orbital Hamilton population(COHP),and molecular orbitals are used to reveal the OER/ORR activity source.Particularly,the Rh/Ir-d orbital is dramatically hybridized with the O-p orbital of the oxygenated adsorbates,so that the lone-electrons incipiently locate at the antibonding orbital pair up and populate the downward bonding orbital,allowing
基金supported by the National Natural Science Foundation of China(91022015 & 20871034)Guangxi Science Foundation of China (0832001Z)the Program for New Century Excellent Talents in University of the Ministry of Education of China and Guangxi Province (NCET-07-217,2006201)
文摘Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to single-crystal(SC-SC) transformation as new method for the direct observation of host-guest chemistry,can reveal the intrinsic relevance and interaction between the framework and guest molecules.This review describes our work concerning PCPs and recent investigations of others,within the last four years,from the viewpoint of crystalline-state transformations of PCPs on guest removal or inclusion processes.Ligand substitution reaction and postsynthetic modification of PCPs in SC-SC fashion which were distinguished from conventional crystalline-state transformation triggered by guest removal or exchange were highlighted in this review.The research status of crystalline-state transformation in China was briefly introduced as well.Series of structure analysis techniques including single-crystal X-ray diffraction,powder X-ray diffraction,neutron diffraction,inelastic neutron scattering as well as the application of synchrotron radiation light source will inevitably promote the advance of study of crystalline-state transformation.And as a hotspot,deep investigations of crystalline-state transformation also help us to overcome the challenge of achieving multifunction and the correlation among them,such as sorption,magnetism,optical or electrical properties simultaneously in PCPs and contribute to design stimulate-oriented porous intelligent materials in the future.
文摘Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral techniques, and Rose-Dragomethod. Electronic effects in metalloporphrins and effects of ligands, temperature andsolvents were investigated. It was found that equilibrium constants for reactions of ZnT(p-X)PP with ligands follow Hammett equation. The changes of standard molar enthalpy△rHm and the changes of standard molar entropy △rSm of the reactions were obtainedfrom the plots of lnK vs. 1/T.
基金supported by the National Natural Science Foundation of China(No.22075099)the Natural Science Foundation of Jilin Province(No.20220101051JC)the Education Department of Jilin Province(No.JJKH20220967KJ)。
文摘Developing transition metal-nitrogen-carbon materials(M-N-C)as electrocatalysts for the oxygen evolution reaction(OER)is significant for low-cost energy conversion systems.Further d-orbital adjustment of M center in M-N-C is beneficial to the improvement of OER performance.Herein,we synthesize a single-Mn-atom catalyst based on carbon skeleton(Mn_(1)-N_(2)S_(2)C_(x))with isolated Mn-N_(2)S_(2)sites,which exhibits high alkaline OER activity(η10=280 mV),low Tafel slope(44 mV·dec^(−1)),and excellent stability.Theoretical calculations reveal the pivotal function of isolated Mn-N_(2)S_(2)sites in promoting OER,including the adsorption kinetics of intermediates and activation mechanism of active sites.The doping of S causes the increase in both charge density and work function of active Mn center,and ortho-Mn_(1)-N_(2)S_(2)C_(x)expresses the fastest OER kinetics due to the asymmetric plane.
