Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional therm...Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs.展开更多
Formic acid oxidation reaction(FAOR),as the anodic reaction in direct formic acid fuel cells,has attracted much attention but increasing the mass activity and stability of catalysts still face a bottleneck to meet the...Formic acid oxidation reaction(FAOR),as the anodic reaction in direct formic acid fuel cells,has attracted much attention but increasing the mass activity and stability of catalysts still face a bottleneck to meet the requirements of practical applications.In the past decades,researchers developed many strategies to fix these issues by improving the structure of catalysts and the newly raised single atom catalysts(SACs)show the high mass activity and stability in FAOR.This review first summarized the reaction mechanism involved in FAOR.The mass activity as well as stability of catalysts reported in the past five years have been outlined.Moreover,the synthetic strategies to improve the catalytic performance of catalysts are also reviewed in this work.Finally,we proposed the research directions to guide the rational design of new FAOR catalysts in the future.展开更多
Fossil fuel depletion and environmental deterioration have created an urgent need to develop renewable and clean energy.Biomass,a sustainable organic carbon source,can meet the huge demand for energy and chemicals.Amo...Fossil fuel depletion and environmental deterioration have created an urgent need to develop renewable and clean energy.Biomass,a sustainable organic carbon source,can meet the huge demand for energy and chemicals.Among them,5-hydroxymethylfurfural(HMF)is an important biomass-derived platform molecule,which can be converted into various high-value chemicals.One of its oxidation products,2,5-furandicarboxylic acid(FDCA),is expected to replace terephthalic acid as a raw material for the synthesis of bio-based degradable plastics.The electrooxidation of HMF emerges as a promising green route for preparing FDCA due to its advantages of mild conditions,fast reaction rate,and high selectivity.The theoretical potential of the HMF electrooxidation reaction(HMFOR,0.3 V vs.reversible hydrogen electrode,RHE)is also lower than that of the oxygen evolution reaction(OER,1.23 V vs.RHE).Coupling anodic HMFOR with cathodic hydrogen evolution reaction(HER)is expected to simultaneously produce valuable FDCA and reduce the cell voltage of hydrogen(H2)evolution.However,the construction of efficient and stable bifunctional catalysts for HMFOR-assisted H2 production is still challenging.In this study,Co-doped Ni-Mo-O porous nanorods grown on a nickel foam(Co-NiMoO/NF)is prepared by simple hydrothermal and calcination methods for both HMFOR and HER.Results of electrocatalytic studies indicate that Co-NiMoO/NF exhibits enhanced performance for HMFOR(E10/100=1.31/1.37 V vs.RHE)and HER(E−10/−100=−35/−123 mV vs.RHE)and shows durable HMFOR/HER stability.In particular,Co-NiMoO/NF maintains high FDCA selectivity(~99.2%)and Faradaic efficiency(~95.7%)for 40 successive cycles at 1.36 V vs.RHE for HMFOR.Conversely,Co-NiMoO/NF maintains stable operation at−200 mA∙cm^(−2)for 50 h with no significant activity attenuation for HER.When coupled as a bifunctional electrode for overall HMF splitting,Co-NiMoO/NF reaches an electric flux of 50 mA∙cm^(−2)at 1.48 V,which is 290 mV lower than that of the overall water splitting.This confirms that the HMFOR-assisted H2 production over Co-NiMoO/NF significantly reduces the energy consumption.Moreover,the two-electrode system maintains good FDCA selectivity(97.6%)for 10 cycles at 1.45 V,implying good stability of HMFOR-assisted H2 evolution.The remarkable catalytic performance of Co-NiMoO/NF could be due to the introduction of Co,which optimizes the electronic structure of Ni-Mo-O and adsorption behaviors of the reactants,thereby enhancing the intrinsic activity and stability of the catalyst.Meanwhile,the porous nanorod structure enhanced the mass transport of substrates and desorption of bubbles,thereby elevating the HMFOR/HER kinetics.This study provides useful insights for designing efficient and durable bifunctional catalysts for HMFOR and HER.展开更多
The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly effici...The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly efficient catalysts for the HzOR.Herein,we report amorphous ruthenium nanosheets(a-Ru NSs)with a thickness of approximately 9.6 nm.As a superior bifunctional electrocatalyst,a-Ru NSs exhibited enhanced electrocatalytic performance toward both the HzOR and hydrogen evolution reaction(HER),outperforming benchmark Pt/C catalysts,where the a-Ru NSs achieved a work-ing potential of merely-76 mV and a low overpotential of only 17 mV to attain a current density of 10 mA·cm^(-2) for the HzOR and HER,respectively.Furthermore,a-Ru NSs displayed a low cell voltage of 28 mV at 10 mA·cm^(-2) for overall hy-drazine splitting in a two-electrode electrolyzer.In situ Raman spectra revealed that the a-Ru NSs can efficiently promote N‒N bond cleavage,thereby producing more*NH_(2)and accelerating the progress of the reaction.展开更多
The phase compositions and properties of Ti3SiC2-based composites with SiC addition of 5%-30% in mass fraction fabricated by in-situ reaction and hot pressing sintering were studied. SiC addition effectively prevented...The phase compositions and properties of Ti3SiC2-based composites with SiC addition of 5%-30% in mass fraction fabricated by in-situ reaction and hot pressing sintering were studied. SiC addition effectively prevented TiC synthesis but facilitated SiC synthesis. The Ti3SiC2/Ti C-SiC composite had better oxidation resistance when SiC added quantity reached 20% but poorer oxidation resistance with SiC addition under 15% than Ti3SiC2/TiC composite at higher temperatures. There were more than half of the original SiC and a few Ti3SiC2 remaining in Ti3SiC2/Ti C-SiC with 20% SiC addition, but all constituents in Ti3Si2/TiC composite were oxidized after 12 h in air at 1500 °C. The oxidation scale thickness of TS30, 1505.78 μm, was near a half of that of T,2715 μm, at 1500 °C for 20 h. Ti3SiC2/Ti C composite had a flexural strength of 474 MPa, which was surpassed by Ti3SiC2/TiC-SiC composites when SiC added amount reached 15%. The strength reached the peak of 518 MPa at 20% SiC added amount.展开更多
基金the“National Natural Science Foundation of China(No.22122202)”.
文摘Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs.
基金Project(22102218)supported by the National Natural Science Foundation of ChinaProject(2022RC1110)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2022QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,China。
文摘Formic acid oxidation reaction(FAOR),as the anodic reaction in direct formic acid fuel cells,has attracted much attention but increasing the mass activity and stability of catalysts still face a bottleneck to meet the requirements of practical applications.In the past decades,researchers developed many strategies to fix these issues by improving the structure of catalysts and the newly raised single atom catalysts(SACs)show the high mass activity and stability in FAOR.This review first summarized the reaction mechanism involved in FAOR.The mass activity as well as stability of catalysts reported in the past five years have been outlined.Moreover,the synthetic strategies to improve the catalytic performance of catalysts are also reviewed in this work.Finally,we proposed the research directions to guide the rational design of new FAOR catalysts in the future.
文摘Fossil fuel depletion and environmental deterioration have created an urgent need to develop renewable and clean energy.Biomass,a sustainable organic carbon source,can meet the huge demand for energy and chemicals.Among them,5-hydroxymethylfurfural(HMF)is an important biomass-derived platform molecule,which can be converted into various high-value chemicals.One of its oxidation products,2,5-furandicarboxylic acid(FDCA),is expected to replace terephthalic acid as a raw material for the synthesis of bio-based degradable plastics.The electrooxidation of HMF emerges as a promising green route for preparing FDCA due to its advantages of mild conditions,fast reaction rate,and high selectivity.The theoretical potential of the HMF electrooxidation reaction(HMFOR,0.3 V vs.reversible hydrogen electrode,RHE)is also lower than that of the oxygen evolution reaction(OER,1.23 V vs.RHE).Coupling anodic HMFOR with cathodic hydrogen evolution reaction(HER)is expected to simultaneously produce valuable FDCA and reduce the cell voltage of hydrogen(H2)evolution.However,the construction of efficient and stable bifunctional catalysts for HMFOR-assisted H2 production is still challenging.In this study,Co-doped Ni-Mo-O porous nanorods grown on a nickel foam(Co-NiMoO/NF)is prepared by simple hydrothermal and calcination methods for both HMFOR and HER.Results of electrocatalytic studies indicate that Co-NiMoO/NF exhibits enhanced performance for HMFOR(E10/100=1.31/1.37 V vs.RHE)and HER(E−10/−100=−35/−123 mV vs.RHE)and shows durable HMFOR/HER stability.In particular,Co-NiMoO/NF maintains high FDCA selectivity(~99.2%)and Faradaic efficiency(~95.7%)for 40 successive cycles at 1.36 V vs.RHE for HMFOR.Conversely,Co-NiMoO/NF maintains stable operation at−200 mA∙cm^(−2)for 50 h with no significant activity attenuation for HER.When coupled as a bifunctional electrode for overall HMF splitting,Co-NiMoO/NF reaches an electric flux of 50 mA∙cm^(−2)at 1.48 V,which is 290 mV lower than that of the overall water splitting.This confirms that the HMFOR-assisted H2 production over Co-NiMoO/NF significantly reduces the energy consumption.Moreover,the two-electrode system maintains good FDCA selectivity(97.6%)for 10 cycles at 1.45 V,implying good stability of HMFOR-assisted H2 evolution.The remarkable catalytic performance of Co-NiMoO/NF could be due to the introduction of Co,which optimizes the electronic structure of Ni-Mo-O and adsorption behaviors of the reactants,thereby enhancing the intrinsic activity and stability of the catalyst.Meanwhile,the porous nanorod structure enhanced the mass transport of substrates and desorption of bubbles,thereby elevating the HMFOR/HER kinetics.This study provides useful insights for designing efficient and durable bifunctional catalysts for HMFOR and HER.
基金supported by the National Key R&D Program of China(2018YFA0702001)National Natural Science Foundation of China(22371268,22301287)+3 种基金Fundamental Research Funds for the Central Universities(WK2060000016)Anhui Provincial Natural Science Foundation(2208085J09,2208085QB33)Collaborative Innovation Program of Hefei Science Center,CAS(2022HSC-CIP020)Youth Innovation Promotion Association of the Chinese Academy of Science(2018494)and USTC Tang Scholar.
文摘The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly efficient catalysts for the HzOR.Herein,we report amorphous ruthenium nanosheets(a-Ru NSs)with a thickness of approximately 9.6 nm.As a superior bifunctional electrocatalyst,a-Ru NSs exhibited enhanced electrocatalytic performance toward both the HzOR and hydrogen evolution reaction(HER),outperforming benchmark Pt/C catalysts,where the a-Ru NSs achieved a work-ing potential of merely-76 mV and a low overpotential of only 17 mV to attain a current density of 10 mA·cm^(-2) for the HzOR and HER,respectively.Furthermore,a-Ru NSs displayed a low cell voltage of 28 mV at 10 mA·cm^(-2) for overall hy-drazine splitting in a two-electrode electrolyzer.In situ Raman spectra revealed that the a-Ru NSs can efficiently promote N‒N bond cleavage,thereby producing more*NH_(2)and accelerating the progress of the reaction.
基金Project(51302206)supported by the National Natural Science Foundation of ChinaProject(2013JK0925)supported by Shaanxi Provincial Department of Education,China+1 种基金Project(SKLSP201308)supported by the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,ChinaProject supported by the State Scholarship Fund,China
文摘The phase compositions and properties of Ti3SiC2-based composites with SiC addition of 5%-30% in mass fraction fabricated by in-situ reaction and hot pressing sintering were studied. SiC addition effectively prevented TiC synthesis but facilitated SiC synthesis. The Ti3SiC2/Ti C-SiC composite had better oxidation resistance when SiC added quantity reached 20% but poorer oxidation resistance with SiC addition under 15% than Ti3SiC2/TiC composite at higher temperatures. There were more than half of the original SiC and a few Ti3SiC2 remaining in Ti3SiC2/Ti C-SiC with 20% SiC addition, but all constituents in Ti3Si2/TiC composite were oxidized after 12 h in air at 1500 °C. The oxidation scale thickness of TS30, 1505.78 μm, was near a half of that of T,2715 μm, at 1500 °C for 20 h. Ti3SiC2/Ti C composite had a flexural strength of 474 MPa, which was surpassed by Ti3SiC2/TiC-SiC composites when SiC added amount reached 15%. The strength reached the peak of 518 MPa at 20% SiC added amount.
