The palladium nanoparticles/carbon nanofibers（Pd NPs/CNFs） catalyst was prepared by the electrospinning method, the hydrazine hydrate solution reduction in an ice bath environment, the high temperature carbonization...The palladium nanoparticles/carbon nanofibers（Pd NPs/CNFs） catalyst was prepared by the electrospinning method, the hydrazine hydrate solution reduction in an ice bath environment, the high temperature carbonization. The catalyst was characterized by X-ray diffraction（XRD）, fieldemission scanning electron microscope（FE-SEM）, and transmission electron microscopy（TEM）. The nanofibers are not cross-linked and arranged in order. The surface of Pd NPs/CNFs is smooth, and it can be observed that a large number of particles were loaded and well-dispersed in carbon fiber matrix, and the particle distribution is uniform. The activity center of catalyst is Pd^（0）. The Pd NPs/CNFs exhibited a high efficiency, good reusability and stability in the Suzuki and Heck reactions. It can be used for at least five consecutive runs without significant loss of its catalytic activity. The good recyclability of Pd NPs/CNFs provides a way to greatly reduce the cost of the catalyst.展开更多
Herein, well-dispersed Palladium(Pd) nanoparticles(NPs) with good catalytic activities were prepared using a wood nanomaterial(WNM) as a reductant and a supporting agent. Various factors that influenced the NP morphol...Herein, well-dispersed Palladium(Pd) nanoparticles(NPs) with good catalytic activities were prepared using a wood nanomaterial(WNM) as a reductant and a supporting agent. Various factors that influenced the NP morphologies, including reaction time, temperature, and precursor concentration were studied. The as-prepared Pd NPs/WNM showed good catalytic performance for Suzuki coupling reactions.展开更多
Dendrimers have already been successfully used in nanoparticle(NP)catalysis for many years,particularly for Pd NP protection towards carbon-carbon coupling reactions.In this paper,assemblies between Pd nanoparticles a...Dendrimers have already been successfully used in nanoparticle(NP)catalysis for many years,particularly for Pd NP protection towards carbon-carbon coupling reactions.In this paper,assemblies between Pd nanoparticles and two generations of“click”dendrimers,with 27(dendrimer-1)and 81(dendrimer-2)triethylene glycol(TEG)termini,respectively,are examined for catalytic peroxidase-like oxidative activity.This catalysis is investigated with o-phenylenediamine(OPD)and H_(2)O_(2)as the substrates in water,displaying different colours.展开更多
The multi walled carbon nanotubes(MWNTs) have always been as the catalyst supporting materials,but for high-performance composite catalysts, the dispersion and functionalization of MWNTs are important challenging prob...The multi walled carbon nanotubes(MWNTs) have always been as the catalyst supporting materials,but for high-performance composite catalysts, the dispersion and functionalization of MWNTs are important challenging problems. In this paper, Electrocatalytically active palladium nanoparticles(Pd NPs) on MWNTs with the high-performance and excellent solubility polymer, poly(dimethylbenzimidazolium) iodide(P(DMBI)-I-)as modifier and glue was first discussed. The results of transmission electron microscopy(TEM) demonstrate a better dispersion of MWNTs with the assist of P(DMBI)-I-. The Raman spectra indicate a strong π-π interaction between MWNTs and P(DMBI)-I-. Taking advantages of the coordination effect of imidazole groups and the electrostatic attraction to Pd NPs, the prepared Pd/MWNTs-P(DMBI)-I-(Pd/MPDI-) hybrid is of well electrocatalytic activity to the ethanol fuel cells by electrochemical measurements. So it is believed that P(DMBI)-Ican be further applied in the dispersion of different carbon-based materials and metal nanoparticles for fabricating more novel composites for catalyst and electrode material.展开更多
A facile and green approach has been developed for fabricating well-dispersed palladium nanoparticles(Pd NPs)supported on the surface of poly(N-vinylpyrrolidone)(PVP)-stabilized polystyrene(PS)microspheres.The strateg...A facile and green approach has been developed for fabricating well-dispersed palladium nanoparticles(Pd NPs)supported on the surface of poly(N-vinylpyrrolidone)(PVP)-stabilized polystyrene(PS)microspheres.The strategy harnesses the reducing ability of PVP and the affinity between PVP and Pd NPs to achieve in situ surface-assisted growth of small noble metal NPs on the PS microspheres,without involving any additional stabilizer or reducing agent.The stabilizer-free formation contributes to the superior availability and accessibility of active sites for catalysis.The resulting PS/Pd composite particles have demonstrated excellent catalytic performance in the probe reaction of 4-nitrophenol reduction.As far as we know,this approach has been the first straightforward in situ deposition of Pd NPs on the PS microspheres,obviating surface treatment and the use of an exogenous reducing agent or a stabilizer.Furthermore,it is extendable to the fabrication of other composite systems,PS/Ag composite particles for example.展开更多
A facile and efficientγ-radiation strategy has been developed to incorporate surface-clean metal nanoparticles(NPs)into UiO-66-NH_(2)in the absence of stabilizing agents and additional reductants.This approach is ena...A facile and efficientγ-radiation strategy has been developed to incorporate surface-clean metal nanoparticles(NPs)into UiO-66-NH_(2)in the absence of stabilizing agents and additional reductants.This approach is enabled by metal ion reduction with active e-aq and H·species derived from water radiolysis.As a result,highly dispersed Pd NPs with narrow size distribution were generated and evenly dispersed in UiO-66-NH_(2).More importantly,the radiation-reduced Pd NPs exhibit significantly enhanced catalytic activity and stability in olefin hydrogenation.Meanwhile,they are also highly active in the catalytic reduction of 4-nitrophenol to 4-aminophenol.Furthermore,the proposed radiation methodology could be successfully extended to prepare other metal NPs such as Au and Pt.Considering thatγ-ray radiation is widely used in industry,this study provides a potentially scalable approach to incorporate metallic nanomaterials into metal-organic frameworks with improved catalytic performance.展开更多
We report the use of palladium nanoparticles(Pd NPs)immobilized on m-aminophenol/formaldehyde resin(APF)-derived porous carbon spheres(Pd@PCS)as heterogeneous catalysts for the reduction of organic dyes.The morphology...We report the use of palladium nanoparticles(Pd NPs)immobilized on m-aminophenol/formaldehyde resin(APF)-derived porous carbon spheres(Pd@PCS)as heterogeneous catalysts for the reduction of organic dyes.The morphology,structure,surface compositions,and textural properties of PCS and the Pd@PCS catalyst were characterized fully to document the excellent catalytic efficiency of Pd@PCS composites.Pd NPs of mean particle size ca.12±0.8 nm were highly dispersed on the surface of PCSs.展开更多
基金the support of the National Natural Science Foundation of China(No.21266016)
文摘The palladium nanoparticles/carbon nanofibers（Pd NPs/CNFs） catalyst was prepared by the electrospinning method, the hydrazine hydrate solution reduction in an ice bath environment, the high temperature carbonization. The catalyst was characterized by X-ray diffraction（XRD）, fieldemission scanning electron microscope（FE-SEM）, and transmission electron microscopy（TEM）. The nanofibers are not cross-linked and arranged in order. The surface of Pd NPs/CNFs is smooth, and it can be observed that a large number of particles were loaded and well-dispersed in carbon fiber matrix, and the particle distribution is uniform. The activity center of catalyst is Pd^（0）. The Pd NPs/CNFs exhibited a high efficiency, good reusability and stability in the Suzuki and Heck reactions. It can be used for at least five consecutive runs without significant loss of its catalytic activity. The good recyclability of Pd NPs/CNFs provides a way to greatly reduce the cost of the catalyst.
基金supported by the Hebei Key Discipline Construction Project
文摘Herein, well-dispersed Palladium(Pd) nanoparticles(NPs) with good catalytic activities were prepared using a wood nanomaterial(WNM) as a reductant and a supporting agent. Various factors that influenced the NP morphologies, including reaction time, temperature, and precursor concentration were studied. The as-prepared Pd NPs/WNM showed good catalytic performance for Suzuki coupling reactions.
基金support from the China Scholarship Council,CSC(YL),the CAPES/Brazil,Process:88881.337360/2019-01CNPq/FAPEMIG,agreement recorded in SICONV:793988/2013(RPL),the MAT2017-88752-R Retos Project from the Ministerio de Economía,Industria y Competitividad,gobierno de España(SM),the Universities of Bordeaux and Rennes 1 and the Centre National de la Recherche Scientifique(CNRS)is gratefully acknowledged.
文摘Dendrimers have already been successfully used in nanoparticle(NP)catalysis for many years,particularly for Pd NP protection towards carbon-carbon coupling reactions.In this paper,assemblies between Pd nanoparticles and two generations of“click”dendrimers,with 27(dendrimer-1)and 81(dendrimer-2)triethylene glycol(TEG)termini,respectively,are examined for catalytic peroxidase-like oxidative activity.This catalysis is investigated with o-phenylenediamine(OPD)and H_(2)O_(2)as the substrates in water,displaying different colours.
文摘The multi walled carbon nanotubes(MWNTs) have always been as the catalyst supporting materials,but for high-performance composite catalysts, the dispersion and functionalization of MWNTs are important challenging problems. In this paper, Electrocatalytically active palladium nanoparticles(Pd NPs) on MWNTs with the high-performance and excellent solubility polymer, poly(dimethylbenzimidazolium) iodide(P(DMBI)-I-)as modifier and glue was first discussed. The results of transmission electron microscopy(TEM) demonstrate a better dispersion of MWNTs with the assist of P(DMBI)-I-. The Raman spectra indicate a strong π-π interaction between MWNTs and P(DMBI)-I-. Taking advantages of the coordination effect of imidazole groups and the electrostatic attraction to Pd NPs, the prepared Pd/MWNTs-P(DMBI)-I-(Pd/MPDI-) hybrid is of well electrocatalytic activity to the ethanol fuel cells by electrochemical measurements. So it is believed that P(DMBI)-Ican be further applied in the dispersion of different carbon-based materials and metal nanoparticles for fabricating more novel composites for catalyst and electrode material.
基金National Natural Science Foundation of China(no.21204030)the MOE&the SAFEA for the 111 Project(B13025)for financial support.
文摘A facile and green approach has been developed for fabricating well-dispersed palladium nanoparticles(Pd NPs)supported on the surface of poly(N-vinylpyrrolidone)(PVP)-stabilized polystyrene(PS)microspheres.The strategy harnesses the reducing ability of PVP and the affinity between PVP and Pd NPs to achieve in situ surface-assisted growth of small noble metal NPs on the PS microspheres,without involving any additional stabilizer or reducing agent.The stabilizer-free formation contributes to the superior availability and accessibility of active sites for catalysis.The resulting PS/Pd composite particles have demonstrated excellent catalytic performance in the probe reaction of 4-nitrophenol reduction.As far as we know,this approach has been the first straightforward in situ deposition of Pd NPs on the PS microspheres,obviating surface treatment and the use of an exogenous reducing agent or a stabilizer.Furthermore,it is extendable to the fabrication of other composite systems,PS/Ag composite particles for example.
基金support from MOST(2015CB351903,2017YFA0207301,and 2014CB931803)National Natural Science Foundation of China(51402282,51373160,21474095,21371162,21673213,and 21521001)+1 种基金CAS Key Research Program of Frontier Sciences(QYZDB-SSW-SLH018)the Fundamental Research Funds for the Central Universities。
文摘A facile and efficientγ-radiation strategy has been developed to incorporate surface-clean metal nanoparticles(NPs)into UiO-66-NH_(2)in the absence of stabilizing agents and additional reductants.This approach is enabled by metal ion reduction with active e-aq and H·species derived from water radiolysis.As a result,highly dispersed Pd NPs with narrow size distribution were generated and evenly dispersed in UiO-66-NH_(2).More importantly,the radiation-reduced Pd NPs exhibit significantly enhanced catalytic activity and stability in olefin hydrogenation.Meanwhile,they are also highly active in the catalytic reduction of 4-nitrophenol to 4-aminophenol.Furthermore,the proposed radiation methodology could be successfully extended to prepare other metal NPs such as Au and Pt.Considering thatγ-ray radiation is widely used in industry,this study provides a potentially scalable approach to incorporate metallic nanomaterials into metal-organic frameworks with improved catalytic performance.
基金supported by the Ministry of Science and Technology,Taiwan(NSC 102-2113-M-002-009-MY3 to KCL)IPM gratefully acknowledges the Department of Science and Technology(DST)in India for support with the INSPIRE Faculty Award(DST/INSPIRE/04/2016/002275).
文摘We report the use of palladium nanoparticles(Pd NPs)immobilized on m-aminophenol/formaldehyde resin(APF)-derived porous carbon spheres(Pd@PCS)as heterogeneous catalysts for the reduction of organic dyes.The morphology,structure,surface compositions,and textural properties of PCS and the Pd@PCS catalyst were characterized fully to document the excellent catalytic efficiency of Pd@PCS composites.Pd NPs of mean particle size ca.12±0.8 nm were highly dispersed on the surface of PCSs.
