A simple one-pot method was developed to prepare Pt Ni alloy nanoparticles,which can be self-decorated on multiwalled carbon nanotubes in [BMIm][BF4] ionic liquid.The nanohybrids are targeting stable nanocatalysts for...A simple one-pot method was developed to prepare Pt Ni alloy nanoparticles,which can be self-decorated on multiwalled carbon nanotubes in [BMIm][BF4] ionic liquid.The nanohybrids are targeting stable nanocatalysts for fuel cell applications.The sizes of the supported Pt Ni nanoparticles are uniform and as small as 1–2 nm.Pt-to-Ni ratio was controllable by simply selecting a Pt Ni alloy target.The alloy nanoparticles with Pt-to-Ni ratio of 1:1 show high catalytic activity and stability for methanol electro-oxidation.The performance is much higher compared with those of both Pt-only nanoparticles and commercial Pt/C catalyst.The electronic structure characterization on the Pt Ni nanoparticles demonstrates that the electrons are transferred from Ni to Pt,which can suppress the CO poisoning effect.展开更多
Ni-base catalysts are promising candidate for the hydrogenation of furfural(FAL) to high-value chemicals.However,slow intermediate desorption and low selectivity limit its implementation.Identifying the catalytic perf...Ni-base catalysts are promising candidate for the hydrogenation of furfural(FAL) to high-value chemicals.However,slow intermediate desorption and low selectivity limit its implementation.Identifying the catalytic performance of each active sites is vital to design hydrogenation catalyst,and tuning the geometrical sites at molecule level in PtNi could lead to the modification of electronic structure,and thus the selectity for the hydrogenation of FAL was modulated.Herein,PtNi hollow nanoframes(PtNi HNFs) with three dimensional(3 D) molecular accessibility were synthesized,EDX results suggested that Ni was evenly distributed inside of the hollow nanoframes,whereas Pt was relatively concentrated at the edges.DFT calculation demonstrated that PtNi significant decrease the desorption energy of the intermediates.This strategy could not only enhance the desorption of intermediates to improve the catalytic performance,but also transfer the adsorption mode of FAL on catalyst surface to selective hydrogenation of FAL to FOL or THFA.The PtNi HNFs catalyst afforded excellent catalytic performance for selective hydrogenation of a broad range of biomass-derived platform chemicals under mild conditions,especially of FAL to furfuryl alcohol(FOL),in quantitative FOL yields(99%) with a high TOF of 2.56 h^(-1).It is found that the superior performance of PtNi HNFs is attributed to its 3 D hierarchical structure and synergistic electronic effects between Pt and Ni.Besides,the kinetic study demonstrated that the activation energy for hydrogenation of FAL was as low as 54.95 kJ mol^(-1).展开更多
In this work,highly monodispersed Pt-Ni alloy nanoparticles were directly deposited on carbon substrate through a facile electrodeposition strategy in the solvent system of N,N-dimethylformamide(DMF).A series of carbo...In this work,highly monodispersed Pt-Ni alloy nanoparticles were directly deposited on carbon substrate through a facile electrodeposition strategy in the solvent system of N,N-dimethylformamide(DMF).A series of carbon supported Pt-Ni alloy electrocatalysts were synthesized under different applied electrode potentials.Among all as-obtained samples,the Pt-Ni/C electrocatalyst deposited at-1.73 V exhibits the optimal specific activity up to 1.850 mA cm^(-2)at 0.9 V vs.RHE,which is 6.85 times higher than that of the commercial Pt/C.Comprehensive physiochemical characterizations and computational evaluations via density functional theory were conducted to unveil the nucleation and growth mechanism of PtNi alloy formation.Compared to the aqueous solution,DMF solvent molecule must not be neglected in avoiding particle agglomeration and synthesis of monodispersed nanoparticles.During the alloy co-deposition process,Ni sites produced through the reduction of Ni(Ⅱ)precursor not only facilitates Pt-Ni alloy crystal nucleation but also in favor of further Pt reduction on the Ni-inserted Pt surface.As for the deposition potential,it adjusts the final particle size.This work provides a hopeful extended Pt-based catalyst layer production strategy for proton exchange membrane fuel cells and a new idea for the nucleation and growth mechanism exploration for electrodeposited Pt alloy.展开更多
PtNi/C nanoparticles with different atomic ratios of Pt/Ni were produced in pulse microwave assisted polyol process. Transmission electron microscopy(TEM) images show uniform morphology. X-ray diffraction(XRD) pattern...PtNi/C nanoparticles with different atomic ratios of Pt/Ni were produced in pulse microwave assisted polyol process. Transmission electron microscopy(TEM) images show uniform morphology. X-ray diffraction(XRD) pattern plus energy dispersive X-ray(EDX) spectroscopy suggests pure composition. Cyclic voltammogram study reveals that PtNi/C nanoparticles synthesized in pulse microwave assisted polyol process have better catalytic activity for the oxidation of methanol to carbon dioxide than those synthesized in continuous process.展开更多
The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathod...The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current density.Herein,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 batteries.Notably,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts recently.Meanwhile,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@CNTs.Furthermore,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery performance.Therefore,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.展开更多
Creating lattice defects and alloying to produce strain effect in Pt-based bimetallic alloys are both effective methods to optimize the crystal and electronic structure and improve the electrocatalytic performance.Unf...Creating lattice defects and alloying to produce strain effect in Pt-based bimetallic alloys are both effective methods to optimize the crystal and electronic structure and improve the electrocatalytic performance.Unfortunately,the principles that govern the alkaline hydrogen evolution reaction(HER)performance remain unclear,which is detrimental to the rational design of efficient Pt-based electrocatalysts.Herein,PtNi alloys with different Pt/Ni ratios and edge dislocations were synthesized,and the effects of Pt/Ni composition and edge dislocations on the alkaline HER electrocatalytic activity of PtNi alloys were systematically studied.Combined experimental and theoretical investigations reveal that tuning Pt/Ni ratio results in only 1.1 times enhancements in Pt mass activity,whereas edge dislocations-induced extra tensile strain on Ni site and compressive strain on Pt site further boost the alkaline HER intrinsic activity at all Pt/Ni ratios.Impressively,the introduction of edge dislocations in PtNi alloys could break the limit of alloying in boosting Pt mass activity and result in up to 13.7-fold enhancement,in the case that Pt and Ni contents are nearly identical and thus edge dislocation density reaches the maximum.Fundamental mechanism studies demonstrate that the edge dislocation strategy could make a breakthrough in facilitating water dissociation kinetics of PtNi alloys.展开更多
采用超声辅助化学法和凝胶化反应相结合的工艺制备了中空铂镍/三维石墨烯电催化剂(PtNi/GCM).利用X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等表征了催化剂的结构、组成及微观形貌.采...采用超声辅助化学法和凝胶化反应相结合的工艺制备了中空铂镍/三维石墨烯电催化剂(PtNi/GCM).利用X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等表征了催化剂的结构、组成及微观形貌.采用电化学工作站和旋转圆盘电极测试了催化剂对氧还原反应的电催化活性和稳定性.结果表明,铂和镍前驱体的不同摩尔比对催化剂的多孔结构、粒子形貌和分散状态影响较大,当摩尔比为1∶1时,所得三维石墨烯中纳米粒子尺寸均一、分散均匀.该PtNi/GCM催化剂对氧还原具有优异的催化活性,在半波电势(0.494 V)处,质量比活性和面积比活性分别为1.09 A/mg Pt和1.02 m A/cm^2,是商业Pt/C的5.4倍和3.5倍(0.20 A/mgPt,0.29 m A/cm2).同时,该催化剂还具有很好的稳定性,循环30000周后,半波电势降低值是商业铂炭的43.6%.展开更多
用溶剂热法合成 PtNi纳米颗粒，将其修饰在玻碳电极表面制成电化学传感器并将其用于检测。探讨了测试底液、富集电位以及富集时间等实验条件对传感器性能的影响。结果表明，在电位为0.5 V 条件下，该传感器检测双酚 A 的线性范围为0.99...用溶剂热法合成 PtNi纳米颗粒，将其修饰在玻碳电极表面制成电化学传感器并将其用于检测。探讨了测试底液、富集电位以及富集时间等实验条件对传感器性能的影响。结果表明，在电位为0.5 V 条件下，该传感器检测双酚 A 的线性范围为0.99～99.9x10－6 mol／L，其检测限为3.36x10－7 mol／L。该传感器选择性好、灵敏度高、具有良好的重现性和稳定性。展开更多
基金supported by the National Natural Science Foundation of China(21229301,21403126)Research Foundation of Education Bureau of Hubei Province,China(D20131302)~~
基金supported by the National Natural Science Foundation of China(No.61274019)the Soochow University-Western University Joint Centre for Synchrotron Radiation Research+1 种基金the Collaborative Innovation Center of Suzhou Nano Science & Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A simple one-pot method was developed to prepare Pt Ni alloy nanoparticles,which can be self-decorated on multiwalled carbon nanotubes in [BMIm][BF4] ionic liquid.The nanohybrids are targeting stable nanocatalysts for fuel cell applications.The sizes of the supported Pt Ni nanoparticles are uniform and as small as 1–2 nm.Pt-to-Ni ratio was controllable by simply selecting a Pt Ni alloy target.The alloy nanoparticles with Pt-to-Ni ratio of 1:1 show high catalytic activity and stability for methanol electro-oxidation.The performance is much higher compared with those of both Pt-only nanoparticles and commercial Pt/C catalyst.The electronic structure characterization on the Pt Ni nanoparticles demonstrates that the electrons are transferred from Ni to Pt,which can suppress the CO poisoning effect.
基金financially supported by the National Key R&D Program of China (No. 2019YFD1100601)the National Key R & D Program of China (2018YFB1501500)+2 种基金the National Natural Science Foundation of China (Nos. 51776206 and 51536009)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01N092)the ‘‘Transformational Technologies for Clean Energy and Demonstration”, the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA21060102)。
文摘Ni-base catalysts are promising candidate for the hydrogenation of furfural(FAL) to high-value chemicals.However,slow intermediate desorption and low selectivity limit its implementation.Identifying the catalytic performance of each active sites is vital to design hydrogenation catalyst,and tuning the geometrical sites at molecule level in PtNi could lead to the modification of electronic structure,and thus the selectity for the hydrogenation of FAL was modulated.Herein,PtNi hollow nanoframes(PtNi HNFs) with three dimensional(3 D) molecular accessibility were synthesized,EDX results suggested that Ni was evenly distributed inside of the hollow nanoframes,whereas Pt was relatively concentrated at the edges.DFT calculation demonstrated that PtNi significant decrease the desorption energy of the intermediates.This strategy could not only enhance the desorption of intermediates to improve the catalytic performance,but also transfer the adsorption mode of FAL on catalyst surface to selective hydrogenation of FAL to FOL or THFA.The PtNi HNFs catalyst afforded excellent catalytic performance for selective hydrogenation of a broad range of biomass-derived platform chemicals under mild conditions,especially of FAL to furfuryl alcohol(FOL),in quantitative FOL yields(99%) with a high TOF of 2.56 h^(-1).It is found that the superior performance of PtNi HNFs is attributed to its 3 D hierarchical structure and synergistic electronic effects between Pt and Ni.Besides,the kinetic study demonstrated that the activation energy for hydrogenation of FAL was as low as 54.95 kJ mol^(-1).
文摘In this work,highly monodispersed Pt-Ni alloy nanoparticles were directly deposited on carbon substrate through a facile electrodeposition strategy in the solvent system of N,N-dimethylformamide(DMF).A series of carbon supported Pt-Ni alloy electrocatalysts were synthesized under different applied electrode potentials.Among all as-obtained samples,the Pt-Ni/C electrocatalyst deposited at-1.73 V exhibits the optimal specific activity up to 1.850 mA cm^(-2)at 0.9 V vs.RHE,which is 6.85 times higher than that of the commercial Pt/C.Comprehensive physiochemical characterizations and computational evaluations via density functional theory were conducted to unveil the nucleation and growth mechanism of PtNi alloy formation.Compared to the aqueous solution,DMF solvent molecule must not be neglected in avoiding particle agglomeration and synthesis of monodispersed nanoparticles.During the alloy co-deposition process,Ni sites produced through the reduction of Ni(Ⅱ)precursor not only facilitates Pt-Ni alloy crystal nucleation but also in favor of further Pt reduction on the Ni-inserted Pt surface.As for the deposition potential,it adjusts the final particle size.This work provides a hopeful extended Pt-based catalyst layer production strategy for proton exchange membrane fuel cells and a new idea for the nucleation and growth mechanism exploration for electrodeposited Pt alloy.
文摘PtNi/C nanoparticles with different atomic ratios of Pt/Ni were produced in pulse microwave assisted polyol process. Transmission electron microscopy(TEM) images show uniform morphology. X-ray diffraction(XRD) pattern plus energy dispersive X-ray(EDX) spectroscopy suggests pure composition. Cyclic voltammogram study reveals that PtNi/C nanoparticles synthesized in pulse microwave assisted polyol process have better catalytic activity for the oxidation of methanol to carbon dioxide than those synthesized in continuous process.
基金supported by the National Natural Science Foundation of China(Nos.22125903 and 51872283)Dalian Innovation Support Plan for High Level Talents(No.2019RT09)+2 种基金Dalian National Laboratory for Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS(Nos.DNL201912,DNL201915,DNL202016,and DNL202019)DICP(No.DICP I2020032)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Nos.YLU‐DNL Fund 2021002 and YLU‐DNL 2021009).
文摘The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current density.Herein,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 batteries.Notably,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts recently.Meanwhile,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@CNTs.Furthermore,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery performance.Therefore,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.
基金the National Natural Science Foundation of China(No.51822106).
文摘Creating lattice defects and alloying to produce strain effect in Pt-based bimetallic alloys are both effective methods to optimize the crystal and electronic structure and improve the electrocatalytic performance.Unfortunately,the principles that govern the alkaline hydrogen evolution reaction(HER)performance remain unclear,which is detrimental to the rational design of efficient Pt-based electrocatalysts.Herein,PtNi alloys with different Pt/Ni ratios and edge dislocations were synthesized,and the effects of Pt/Ni composition and edge dislocations on the alkaline HER electrocatalytic activity of PtNi alloys were systematically studied.Combined experimental and theoretical investigations reveal that tuning Pt/Ni ratio results in only 1.1 times enhancements in Pt mass activity,whereas edge dislocations-induced extra tensile strain on Ni site and compressive strain on Pt site further boost the alkaline HER intrinsic activity at all Pt/Ni ratios.Impressively,the introduction of edge dislocations in PtNi alloys could break the limit of alloying in boosting Pt mass activity and result in up to 13.7-fold enhancement,in the case that Pt and Ni contents are nearly identical and thus edge dislocation density reaches the maximum.Fundamental mechanism studies demonstrate that the edge dislocation strategy could make a breakthrough in facilitating water dissociation kinetics of PtNi alloys.
文摘采用超声辅助化学法和凝胶化反应相结合的工艺制备了中空铂镍/三维石墨烯电催化剂(PtNi/GCM).利用X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等表征了催化剂的结构、组成及微观形貌.采用电化学工作站和旋转圆盘电极测试了催化剂对氧还原反应的电催化活性和稳定性.结果表明,铂和镍前驱体的不同摩尔比对催化剂的多孔结构、粒子形貌和分散状态影响较大,当摩尔比为1∶1时,所得三维石墨烯中纳米粒子尺寸均一、分散均匀.该PtNi/GCM催化剂对氧还原具有优异的催化活性,在半波电势(0.494 V)处,质量比活性和面积比活性分别为1.09 A/mg Pt和1.02 m A/cm^2,是商业Pt/C的5.4倍和3.5倍(0.20 A/mgPt,0.29 m A/cm2).同时,该催化剂还具有很好的稳定性,循环30000周后,半波电势降低值是商业铂炭的43.6%.
文摘用溶剂热法合成 PtNi纳米颗粒，将其修饰在玻碳电极表面制成电化学传感器并将其用于检测。探讨了测试底液、富集电位以及富集时间等实验条件对传感器性能的影响。结果表明，在电位为0.5 V 条件下，该传感器检测双酚 A 的线性范围为0.99～99.9x10－6 mol／L，其检测限为3.36x10－7 mol／L。该传感器选择性好、灵敏度高、具有良好的重现性和稳定性。
