Electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)plays an important role in deciphering interfacial reaction mechanisms at molecular level.However,the corrosive ...Electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)plays an important role in deciphering interfacial reaction mechanisms at molecular level.However,the corrosive etching of Si internal reflection element by OH−largely impedes reliable SEIRAS measurements in strong alkaline electrolytes.Herein,a dense and chemically inert nanocrystalline diamond(NCD)film is successfully fabricated at a thickness of~120 nm through hot filament chemical vapor deposition on a micromachined Si wafer to insulate the OH^(−)etching.A reversible interfacial water feature without spectral interference of Si-O band is obtained in 1.0 mol·L^(–1)KOH on Au/NCD/Si film electrode.Afterwards,electrochemical CO reduction reaction on Cu film electrode is explored in different KOH concentrations ranging from 0.1 to 3.0 mol·L^(-1)as a model reaction.A redshift of CO_(L)band,as well as its lower intensity but faster depletion kinetics,is noted with increasing electrolyte pH,whereas CO_(B)is identified as an inert spectator accumulating on Cu surface.Our present work demonstrates the alkaline resistant feature of diamond/Si composite internal reflection element,which could be a powerful platform to study electrocatalytic reactions in strong alkaline media.展开更多
Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Here...Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.展开更多
Engineering the desired dual metal sites to realize C-C coupling of CO_(2)is of great importance for the practical applications of CO_(2)electroreduction reaction(CER).Herein,an efficient strategy for constructing het...Engineering the desired dual metal sites to realize C-C coupling of CO_(2)is of great importance for the practical applications of CO_(2)electroreduction reaction(CER).Herein,an efficient strategy for constructing heterogeneous Pt^(δ+)-Cu^(δ+)dual sites to strengthen the generation and coupling of*CO and*CHO(or*COH)during CER process is presented in this work.The radiilarger Pt not only stabilizes the Cu^(δ+)ut also induces a tensile strain in Pt^(δ+)-Cu^(δ+)dual sites.The obtained Pt^(δ+)-Cu^(δ+)dual sites achieve a total Faradaic efficiency and current density of C2products with 70.9%and586.9 mA·cm-2at-1.20 V(vs.RHE),which is higher than that of Cu^(δ+)single site(55.4%,286.9 mA·cm^(-2)).The in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)reveals that the Pt^(δ+)-Cu^(δ+)dual sites can promote the generation of C1intermediates(such as*CO,*COOH,*COH,and*CHO)and C-C coupling.Additional in situ surface-enhanced Raman spectra demonstrate that Pt^(δ+)Cu^(δ+)dual sites can induce the generation of the high-frequency peak for*CO_(atop),thus accelerating the C-C coupling.This work provides a promising avenue for stabilizing and enhancing the performance of Cu^(δ+)sites toward CER.展开更多
Cobalt(Co)metallization presents a promising alternative strategy for the bottom interconnect in advanced chip manufacture,yet the interfacial structure and functionality of an organic additive essential for superconf...Cobalt(Co)metallization presents a promising alternative strategy for the bottom interconnect in advanced chip manufacture,yet the interfacial structure and functionality of an organic additive essential for superconformal Co deposition is far from clear given the concurring hydrogen evolution reaction(HER).Herein,interfacial electrochemistry for a model additive molecule MBIS(sodium 2-mercapto-5-benzimidazolesulfonate)at a Co electrode is investigated by applying in situ surface-enhanced infrared absorption spectroscopy and electrochemical quartz crystal microbalance combined with density functional theory calculations.The vertical plane adsorption of MBIS on the Co surface via thiolate reduces the overall reduction current with a higher/lower Faradaic efficiency(FE)towards HER/Co deposition due to the significant blockage of surface Co sites as well as the formation of Co(Ⅱ)complex with MBIS.Surface coverage of MBIS is found to decrease with increasing pH and overpotential,which may account for the location-dependent functionality of MBIS in practical Co deposition in vias.This work provides a molecularlevel insight into the interfacial mechanism of an organic additive essential for the Co superfilling scenario.展开更多
The electrochemical reduction of CO_(2)to multi-carbon(C_(2+))products is a promising strategy for sustainable fuel and chemical production and CO_(2)emission mitigation.However,optimizing^(*)CO intermediate generatio...The electrochemical reduction of CO_(2)to multi-carbon(C_(2+))products is a promising strategy for sustainable fuel and chemical production and CO_(2)emission mitigation.However,optimizing^(*)CO intermediate generation and utilization in complex multi-electron systems is crucial for the C_(2)products,but it remains challenging.Herein,we synthesize a yolk-shell structured Cu@HCS catalyst via hydrothermal synthesis coupled with high-temperature calcination,featuring a unique copper core and hollow carbon shell nanostructure.This architecture significantly enhances the selectivity toward C_(2)products during electrocatalytic CO_(2)reduction.The optimized Cu@HCS-2-800 catalyst achieves a Faradaic efficiency(FE)of 69.7%for C_(2)products at-1.4 V vs.reversible hydrogen electrode(RHE),markedly surpassing the 30.1%FE of conventional Cu/xc-72 catalyst.Furthermore,the yolk-shell configuration suppresses hydrogen evolution,ensuring superior stability during prolonged operation.In situ attenuated total reflectance-surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)and density functional theory(DFT)analysis reveal that the Cu@HCS-2-800 catalyst leverages spatial confinement effects to retard CO diffusion and promote CO re-adsorption,thereby elevating^(*)CO intermediate coverage to enhance C-C coupling.This work underscores the pivotal role of nanoscale spatial confinement in advancing CO_(2)electroreduction performance and provides a guidance for designing advanced catalysts with tailored microenvironment.展开更多
The development of efficient non-precious metal catalysts is important for the large-scale application of alkaline hydrogen evolution reaction(HER).Here,we synthesized a composite catalyst of Cu and Mo_(2)C(Cu/Mo_(2)C...The development of efficient non-precious metal catalysts is important for the large-scale application of alkaline hydrogen evolution reaction(HER).Here,we synthesized a composite catalyst of Cu and Mo_(2)C(Cu/Mo_(2)C)using Anderson-type polyoxometalates(POMs)synthesized by the facile soaking method as precursors.The electronic interaction between Cu and Mo_(2)C drives the positive charge of Cu,alleviating the strong adsorption of hydrogen at the Mo site by modulating the d-band center of Mo_(2)C.By studying the interfacial water structure using in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS),we determined that the positively charged Cu crystals have the function of activating water molecules and optimizing the interfacial water structure.The interfacial water of Cu/Mo_(2)C contains a large amount of free water,which could facilitate the transport of reaction intermediates.Due to activated water molecules and optimized interfacial water structure and hydrogen adsorption energy,the overpotential of Cu/Mo_(2)C is 24 mV at a current density of 10 mA·cm^(-2) and 178 mV at a current density of 1000 mA·cm^(-2).This work improves catalyst performance in terms of interfacial water structure optimization and deepens the understanding of water-mediated catalysis.展开更多
Electrocatalytic reduction of CO_(2) to fuels and chemicals possesses huge potential to alleviate current environmental crisis.Heteroatom doping in metal-nitrogen-carbon(M-N-C)single-atom catalysts(SACs)has been found...Electrocatalytic reduction of CO_(2) to fuels and chemicals possesses huge potential to alleviate current environmental crisis.Heteroatom doping in metal-nitrogen-carbon(M-N-C)single-atom catalysts(SACs)has been found to be capable to promote the electrocatalytic CO_(2) reduction reaction(CO_(2)RR).However,the origin of the enhanced activity is still elusive.Here,we report that sulfur-doped cobalt-nitrogen-carbon single-atom catalyst(Co1-SNC)exhibits superior CO_(2)RR performance compared to sulfur-free counterpart(Co1-NC).On the basis of in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS),kinetic isotope effect(KIE)and theoretical calculation,it is demonstrated that sulfur doping can promote water activation,elevate the d-band center of Co active site,and reduce the free energy of*COOH intermediate formation.This work deepens the understanding of the CO_(2)RR chemistry over heteroatom-doped SACs for designing efficient CO_(2)RR processes.展开更多
Attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)has recently been proven to be a powerful tool for bioanalysis.It enables in situ and in real-time observation of dynamic proces...Attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)has recently been proven to be a powerful tool for bioanalysis.It enables in situ and in real-time observation of dynamic processes occurring on specific interface,revealing rich structural and functional information of biomolecules at sub monolayer level.The aim of this general review was to give an overview of the cutting edge applications of ATRSEIRAS.We start with description of the basic configuration of the standard ATR-SEIRAS platform.The enhanced mechanisms and methods to fabricate enhanced substrates are then presented.We discuss the recent developments,challenges and applications of ATR-SEIRAS in bioanalysis,mainly focusing on DNA analysis,protein behavior and cell properties.Finally,further development of the ATRSEIRAS technique with enhanced sensitivity,improved time and spatial resolutions will be prospected.展开更多
CO_(2) electroreduction (CO_(2) ER) using renewable energy is ideal for mitigating the greenhouse effect and closing the carbon cycle. Bicarbonate (HCO_(3)−) is most commonly employed as the electrolyte anion because ...CO_(2) electroreduction (CO_(2) ER) using renewable energy is ideal for mitigating the greenhouse effect and closing the carbon cycle. Bicarbonate (HCO_(3)−) is most commonly employed as the electrolyte anion because it is known to facilitate CO_(2) ER. However, its dynamics in the electric double layer remains obscure and requires more in-depth investigation. Herein, we investigate the refined reduction process of bicarbonate by employing in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy. By comparing the product distributions in Ar-saturated KCl and KHCO_(3) electrolytes, we confirmed CO production from HCO_(3)^(−) in the absence of an external CO_(2) source. Notably, in contrast to an electric compulsion, negatively charged HCO_(3)− anions were found to accumulate near the electrode surface. A reduction mechanism of HCO3− is proposed in that HCO3− is not adsorbed over a catalyst, but may be enriched near the electrode surface and converted to CO_(2) and react over Au and Cu electrodes. The dependence of the CO_(2) ER activity on the local HCO3− concentration was subsequently discovered, which was in turn dependent on the bulk HCO3− concentration and cathodic potential. In particular, the local HCO3− concentration was limited by the cathodic potential, leading to a plateau in the CO_(2) ER activity. The proposed mechanism provides insights into the interaction between the catalyst and the electrolyte in CO_(2) ER.展开更多
Through interface engineering and content control strategy,a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO_(2)to formate with a remarkably high Faraday efficiency(FEf...Through interface engineering and content control strategy,a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO_(2)to formate with a remarkably high Faraday efficiency(FEformate)of 94%and a partial current density(jformate)of 34 mA·cm^(−2)at−0.8 V vs.reversible hydrogen electrode(RHE)in an H-cell.Moreover,the PdBi interface electrocatalyst even exhibited a high current density of 180 mA·cm^(−2)with formate selectivity up to 92%in a flow cell and could steadily operate for at least 20 h.Electrochemical in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirmed that the PdBi interface could greatly weaken the adsorption of*CO intermediates due to electronic and geometric effects.Density functional theory(DFT)calculations also established that the PdBi interface regulated the CO_(2)-to-formate pathway by reducing the energy barrier toward HCOOH and largely weakening the adsorption of*CO intermediates on the catalyst surface.This study reveals that the unique PdBi bimetallic interface can provide a novel platform to study the reaction mechanism through combining in-situ ATR-SEIRAS and DFT calculations.展开更多
基金supported by the National Key R&D Program of China(2022YFB4102000,2022YFA1503803 and 2022YFA1505100)National Natural Science Foundation of China(22002088,22272033,22241201 and 52175423)Shanghai Science and Technology Innovation Action Plan(22dz1205500).
文摘Electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)plays an important role in deciphering interfacial reaction mechanisms at molecular level.However,the corrosive etching of Si internal reflection element by OH−largely impedes reliable SEIRAS measurements in strong alkaline electrolytes.Herein,a dense and chemically inert nanocrystalline diamond(NCD)film is successfully fabricated at a thickness of~120 nm through hot filament chemical vapor deposition on a micromachined Si wafer to insulate the OH^(−)etching.A reversible interfacial water feature without spectral interference of Si-O band is obtained in 1.0 mol·L^(–1)KOH on Au/NCD/Si film electrode.Afterwards,electrochemical CO reduction reaction on Cu film electrode is explored in different KOH concentrations ranging from 0.1 to 3.0 mol·L^(-1)as a model reaction.A redshift of CO_(L)band,as well as its lower intensity but faster depletion kinetics,is noted with increasing electrolyte pH,whereas CO_(B)is identified as an inert spectator accumulating on Cu surface.Our present work demonstrates the alkaline resistant feature of diamond/Si composite internal reflection element,which could be a powerful platform to study electrocatalytic reactions in strong alkaline media.
基金financially supported by the Natural Science Foundation of Guangdong Province (2022A1515012359)the National Natural Science Foundation of China (21902121)+1 种基金the STU Scientific Research Foundation for Talents (NTF21020)the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant (2020LKSFG09A)。
文摘Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.
基金financially supported by the National Natural Science Foundation of China(No.22305101)the Natural Science Foundation of Jiangsu Province(No.BK20231032)+2 种基金the Special Fund Project of Jiangsu Province for Scientific and Technological Innovation in Carbon Peaking and Carbon Neutrality(No.BK20220023)the Fundamental Research Funds for the Central Universities(No.JUSRP123020)the Startup Funding at Jiangnan University(No.1045219032220100)。
文摘Engineering the desired dual metal sites to realize C-C coupling of CO_(2)is of great importance for the practical applications of CO_(2)electroreduction reaction(CER).Herein,an efficient strategy for constructing heterogeneous Pt^(δ+)-Cu^(δ+)dual sites to strengthen the generation and coupling of*CO and*CHO(or*COH)during CER process is presented in this work.The radiilarger Pt not only stabilizes the Cu^(δ+)ut also induces a tensile strain in Pt^(δ+)-Cu^(δ+)dual sites.The obtained Pt^(δ+)-Cu^(δ+)dual sites achieve a total Faradaic efficiency and current density of C2products with 70.9%and586.9 mA·cm-2at-1.20 V(vs.RHE),which is higher than that of Cu^(δ+)single site(55.4%,286.9 mA·cm^(-2)).The in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)reveals that the Pt^(δ+)-Cu^(δ+)dual sites can promote the generation of C1intermediates(such as*CO,*COOH,*COH,and*CHO)and C-C coupling.Additional in situ surface-enhanced Raman spectra demonstrate that Pt^(δ+)Cu^(δ+)dual sites can induce the generation of the high-frequency peak for*CO_(atop),thus accelerating the C-C coupling.This work provides a promising avenue for stabilizing and enhancing the performance of Cu^(δ+)sites toward CER.
基金supported by the National Natural Science Foundation of China(22272033,22241201,22402167)the Science and Technology Commission of Shanghai Municipality(2024ZDSYS02)。
文摘Cobalt(Co)metallization presents a promising alternative strategy for the bottom interconnect in advanced chip manufacture,yet the interfacial structure and functionality of an organic additive essential for superconformal Co deposition is far from clear given the concurring hydrogen evolution reaction(HER).Herein,interfacial electrochemistry for a model additive molecule MBIS(sodium 2-mercapto-5-benzimidazolesulfonate)at a Co electrode is investigated by applying in situ surface-enhanced infrared absorption spectroscopy and electrochemical quartz crystal microbalance combined with density functional theory calculations.The vertical plane adsorption of MBIS on the Co surface via thiolate reduces the overall reduction current with a higher/lower Faradaic efficiency(FE)towards HER/Co deposition due to the significant blockage of surface Co sites as well as the formation of Co(Ⅱ)complex with MBIS.Surface coverage of MBIS is found to decrease with increasing pH and overpotential,which may account for the location-dependent functionality of MBIS in practical Co deposition in vias.This work provides a molecularlevel insight into the interfacial mechanism of an organic additive essential for the Co superfilling scenario.
基金supported by the National Natural Science Foundation of China(No.21902121)Natural Science Foundation of Guangdong Province(Nos.2022A1515012359 and 2025A1515011015)+1 种基金STU Scientific Research Foundation for Talents(NO.NTF21020)the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(No.2020LKSFG09A).
文摘The electrochemical reduction of CO_(2)to multi-carbon(C_(2+))products is a promising strategy for sustainable fuel and chemical production and CO_(2)emission mitigation.However,optimizing^(*)CO intermediate generation and utilization in complex multi-electron systems is crucial for the C_(2)products,but it remains challenging.Herein,we synthesize a yolk-shell structured Cu@HCS catalyst via hydrothermal synthesis coupled with high-temperature calcination,featuring a unique copper core and hollow carbon shell nanostructure.This architecture significantly enhances the selectivity toward C_(2)products during electrocatalytic CO_(2)reduction.The optimized Cu@HCS-2-800 catalyst achieves a Faradaic efficiency(FE)of 69.7%for C_(2)products at-1.4 V vs.reversible hydrogen electrode(RHE),markedly surpassing the 30.1%FE of conventional Cu/xc-72 catalyst.Furthermore,the yolk-shell configuration suppresses hydrogen evolution,ensuring superior stability during prolonged operation.In situ attenuated total reflectance-surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)and density functional theory(DFT)analysis reveal that the Cu@HCS-2-800 catalyst leverages spatial confinement effects to retard CO diffusion and promote CO re-adsorption,thereby elevating^(*)CO intermediate coverage to enhance C-C coupling.This work underscores the pivotal role of nanoscale spatial confinement in advancing CO_(2)electroreduction performance and provides a guidance for designing advanced catalysts with tailored microenvironment.
基金supported by National Natural Science Foundation of China(Nos.52376060 and 51976081).
文摘The development of efficient non-precious metal catalysts is important for the large-scale application of alkaline hydrogen evolution reaction(HER).Here,we synthesized a composite catalyst of Cu and Mo_(2)C(Cu/Mo_(2)C)using Anderson-type polyoxometalates(POMs)synthesized by the facile soaking method as precursors.The electronic interaction between Cu and Mo_(2)C drives the positive charge of Cu,alleviating the strong adsorption of hydrogen at the Mo site by modulating the d-band center of Mo_(2)C.By studying the interfacial water structure using in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS),we determined that the positively charged Cu crystals have the function of activating water molecules and optimizing the interfacial water structure.The interfacial water of Cu/Mo_(2)C contains a large amount of free water,which could facilitate the transport of reaction intermediates.Due to activated water molecules and optimized interfacial water structure and hydrogen adsorption energy,the overpotential of Cu/Mo_(2)C is 24 mV at a current density of 10 mA·cm^(-2) and 178 mV at a current density of 1000 mA·cm^(-2).This work improves catalyst performance in terms of interfacial water structure optimization and deepens the understanding of water-mediated catalysis.
基金financially supported by National Natural Science Foundation of China(No.21974103)the start-up funds of Wuhan University and the Experimental Supporting System at Shanghai Synchrotron Radiation Facility.
文摘Electrocatalytic reduction of CO_(2) to fuels and chemicals possesses huge potential to alleviate current environmental crisis.Heteroatom doping in metal-nitrogen-carbon(M-N-C)single-atom catalysts(SACs)has been found to be capable to promote the electrocatalytic CO_(2) reduction reaction(CO_(2)RR).However,the origin of the enhanced activity is still elusive.Here,we report that sulfur-doped cobalt-nitrogen-carbon single-atom catalyst(Co1-SNC)exhibits superior CO_(2)RR performance compared to sulfur-free counterpart(Co1-NC).On the basis of in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS),kinetic isotope effect(KIE)and theoretical calculation,it is demonstrated that sulfur doping can promote water activation,elevate the d-band center of Co active site,and reduce the free energy of*COOH intermediate formation.This work deepens the understanding of the CO_(2)RR chemistry over heteroatom-doped SACs for designing efficient CO_(2)RR processes.
基金This work was supported by grants from the National Natural Science Foundation of China(21327902,21635004,21675079,21627806).
文摘Attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)has recently been proven to be a powerful tool for bioanalysis.It enables in situ and in real-time observation of dynamic processes occurring on specific interface,revealing rich structural and functional information of biomolecules at sub monolayer level.The aim of this general review was to give an overview of the cutting edge applications of ATRSEIRAS.We start with description of the basic configuration of the standard ATR-SEIRAS platform.The enhanced mechanisms and methods to fabricate enhanced substrates are then presented.We discuss the recent developments,challenges and applications of ATR-SEIRAS in bioanalysis,mainly focusing on DNA analysis,protein behavior and cell properties.Finally,further development of the ATRSEIRAS technique with enhanced sensitivity,improved time and spatial resolutions will be prospected.
基金This work is supported by the National Key Research and Development Program of China(2016YFB0600901)the National Natural Science Foundation of China(21525626,22038009,51861125104)the Program of Introducing Talents of Discipline to Universities(No.BP0618007)for financial support.
文摘CO_(2) electroreduction (CO_(2) ER) using renewable energy is ideal for mitigating the greenhouse effect and closing the carbon cycle. Bicarbonate (HCO_(3)−) is most commonly employed as the electrolyte anion because it is known to facilitate CO_(2) ER. However, its dynamics in the electric double layer remains obscure and requires more in-depth investigation. Herein, we investigate the refined reduction process of bicarbonate by employing in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy. By comparing the product distributions in Ar-saturated KCl and KHCO_(3) electrolytes, we confirmed CO production from HCO_(3)^(−) in the absence of an external CO_(2) source. Notably, in contrast to an electric compulsion, negatively charged HCO_(3)− anions were found to accumulate near the electrode surface. A reduction mechanism of HCO3− is proposed in that HCO3− is not adsorbed over a catalyst, but may be enriched near the electrode surface and converted to CO_(2) and react over Au and Cu electrodes. The dependence of the CO_(2) ER activity on the local HCO3− concentration was subsequently discovered, which was in turn dependent on the bulk HCO3− concentration and cathodic potential. In particular, the local HCO3− concentration was limited by the cathodic potential, leading to a plateau in the CO_(2) ER activity. The proposed mechanism provides insights into the interaction between the catalyst and the electrolyte in CO_(2) ER.
基金supported by the National Natural Science Foundation of China(Nos.22003074 and 22002087)Youth Innovation Promotion Association CAS,Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials(No.2021MCIMKF03)Baoshan Iron&Steel Co.,Ltd.(Baosteel),located in Shanghai,China.
文摘Through interface engineering and content control strategy,a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO_(2)to formate with a remarkably high Faraday efficiency(FEformate)of 94%and a partial current density(jformate)of 34 mA·cm^(−2)at−0.8 V vs.reversible hydrogen electrode(RHE)in an H-cell.Moreover,the PdBi interface electrocatalyst even exhibited a high current density of 180 mA·cm^(−2)with formate selectivity up to 92%in a flow cell and could steadily operate for at least 20 h.Electrochemical in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirmed that the PdBi interface could greatly weaken the adsorption of*CO intermediates due to electronic and geometric effects.Density functional theory(DFT)calculations also established that the PdBi interface regulated the CO_(2)-to-formate pathway by reducing the energy barrier toward HCOOH and largely weakening the adsorption of*CO intermediates on the catalyst surface.This study reveals that the unique PdBi bimetallic interface can provide a novel platform to study the reaction mechanism through combining in-situ ATR-SEIRAS and DFT calculations.
