In this study, a novel core-shell structure of ZSM-5@Mg(Al)O(abbreviated as Z@MA) was designed by using the sol-gel method, and the influence of different weight ratios of Mg(Al)O/ZSM-5 on the structure and catalytic ...In this study, a novel core-shell structure of ZSM-5@Mg(Al)O(abbreviated as Z@MA) was designed by using the sol-gel method, and the influence of different weight ratios of Mg(Al)O/ZSM-5 on the structure and catalytic performance was investigated. The as-obtained materials were characterized by XRD, N_2-physisorption, SEM, FT-IR, NH_3-TPD and XPS analyses. The results showed that, with the increase of the weight ratio of Mg(Al)O/ZSM-5, the thickness of Mg(Al)O shell was improved, and the pore structure and physiochemical properties of core-shell materials were directly modified. After introduction of Mg(Al)O, the acidity properties of different materials were significantly suppressed. Meanwhile, more Sn oxide species in Z@MA could facilitate the anchoring of Pt on the support. By effectively employing these modifications, the capacity of the catalysts to accommodate coke was significanty improved and the carbon deposits were migrated from active metal to the carrier. When the weight ratio was equal to 3, the catalyst PtSnNa/Z@MA showed a highest conversion and high selectivity in propane dehydrogenation.展开更多
A core shell structured C@MoxTi1-xO2-δnanocrystal with a functionalized interface(C@MTNC-FI)was fabricated via the hydrothermal method with subsequent annealing derived from tetrabutyl orthotitanate.The formation of ...A core shell structured C@MoxTi1-xO2-δnanocrystal with a functionalized interface(C@MTNC-FI)was fabricated via the hydrothermal method with subsequent annealing derived from tetrabutyl orthotitanate.The formation of anatase TiO2 was inhibited by the simultaneous presence of the hydrothermal etching/regrowth process,infiltration of Mo dopants and carbon coating,which endows the C@MTNC-FI with an ultrafine crystalline architecture that has a Mo-functionalized interface and carbon-coated shell.Pt Ru nanoparticles(NPs)were supported on C@MTNC-FI by employing a microwave-assisted polyol process(MAPP).The obtained Pt Ru/C@MTNC-FI catalyst has 2.68 times higher mass activity towards methanol electrooxidation than that of the un-functionalized catalyst(Pt Ru/C@TNC)and 1.65 times higher mass activity than that of Pt Ru/C catalyst with over 25%increase in durability.The improved catalytic performance is due to several aspects including ultrafine crystals of TiO2 with abundant grain boundaries,Mofunctionalized interface with enhanced electron interactions,and core shell architecture with excellent electrical transport properties.This work suggests the potential application of an interface-functionalized crystalline material as a sustainable and clean energy solution.展开更多
Pd@Ru bimetallic nanoparticles deposited on carbon black electro-catalysts have been fabricated by microwave-assisted polyol reduction method and investigated for methanol electro-oxidation （MEO）. The structure and ...Pd@Ru bimetallic nanoparticles deposited on carbon black electro-catalysts have been fabricated by microwave-assisted polyol reduction method and investigated for methanol electro-oxidation （MEO）. The structure and electro-catalytic properties of the as-prepared catalysts were characterized by XRD, SEM, TEM and cyclic voltammetry （CV） techniques. The results showed that the introduction of Ru element （2-10 wt%） into Pd 20 wt%/C （hereafter, denoted as Pd/C） produced a series of core-shell structured binary catalysts. Pd@Ru 5 wt%/C （hereafter, denoted as Pd@Rus/C） catalyst displayed the highest catalytic activity towards MEO. And the mass activity of Pd@Ru5/C electrode catalyst at E = -0.038 V （vs. Hg/HgO） was 1.42 times higher than that of Pd/C electrode catalyst. In addition, the relationship between the catalytic stability for MEO on Pd@Ru/C catalysts and the value of dbp/dfp （the ratio of MEO peak current density in the negative scan and positive scan） were also investigated. The result demonstrated that Pd@Rus/C offering the smallest value of Jbp/Jfp displayed the best stable catalytic performance.展开更多
文摘In this study, a novel core-shell structure of ZSM-5@Mg(Al)O(abbreviated as Z@MA) was designed by using the sol-gel method, and the influence of different weight ratios of Mg(Al)O/ZSM-5 on the structure and catalytic performance was investigated. The as-obtained materials were characterized by XRD, N_2-physisorption, SEM, FT-IR, NH_3-TPD and XPS analyses. The results showed that, with the increase of the weight ratio of Mg(Al)O/ZSM-5, the thickness of Mg(Al)O shell was improved, and the pore structure and physiochemical properties of core-shell materials were directly modified. After introduction of Mg(Al)O, the acidity properties of different materials were significantly suppressed. Meanwhile, more Sn oxide species in Z@MA could facilitate the anchoring of Pt on the support. By effectively employing these modifications, the capacity of the catalysts to accommodate coke was significanty improved and the carbon deposits were migrated from active metal to the carrier. When the weight ratio was equal to 3, the catalyst PtSnNa/Z@MA showed a highest conversion and high selectivity in propane dehydrogenation.
基金the National Natural Science Foundation of China (Grant Nos. 21273058, 21673064, 51802059 and 21503059)China Postdoctoral Science Foundation (Grant Nos. 2018M631938, 2018T110307 and 2017M621284)+1 种基金Heilongjiang Postdoctoral Fund (LBH-Z17074)Fundamental Research Funds for the Central Universities (Grant No. HIT. NSRIF. 2019040 and 2019041)
文摘A core shell structured C@MoxTi1-xO2-δnanocrystal with a functionalized interface(C@MTNC-FI)was fabricated via the hydrothermal method with subsequent annealing derived from tetrabutyl orthotitanate.The formation of anatase TiO2 was inhibited by the simultaneous presence of the hydrothermal etching/regrowth process,infiltration of Mo dopants and carbon coating,which endows the C@MTNC-FI with an ultrafine crystalline architecture that has a Mo-functionalized interface and carbon-coated shell.Pt Ru nanoparticles(NPs)were supported on C@MTNC-FI by employing a microwave-assisted polyol process(MAPP).The obtained Pt Ru/C@MTNC-FI catalyst has 2.68 times higher mass activity towards methanol electrooxidation than that of the un-functionalized catalyst(Pt Ru/C@TNC)and 1.65 times higher mass activity than that of Pt Ru/C catalyst with over 25%increase in durability.The improved catalytic performance is due to several aspects including ultrafine crystals of TiO2 with abundant grain boundaries,Mofunctionalized interface with enhanced electron interactions,and core shell architecture with excellent electrical transport properties.This work suggests the potential application of an interface-functionalized crystalline material as a sustainable and clean energy solution.
基金supported by the National Basic Research Program of China(2013CB934001)the Natural Science Foundation of Beijing(2051001)the Natural Science Foundation of China(51074011)
文摘Pd@Ru bimetallic nanoparticles deposited on carbon black electro-catalysts have been fabricated by microwave-assisted polyol reduction method and investigated for methanol electro-oxidation （MEO）. The structure and electro-catalytic properties of the as-prepared catalysts were characterized by XRD, SEM, TEM and cyclic voltammetry （CV） techniques. The results showed that the introduction of Ru element （2-10 wt%） into Pd 20 wt%/C （hereafter, denoted as Pd/C） produced a series of core-shell structured binary catalysts. Pd@Ru 5 wt%/C （hereafter, denoted as Pd@Rus/C） catalyst displayed the highest catalytic activity towards MEO. And the mass activity of Pd@Ru5/C electrode catalyst at E = -0.038 V （vs. Hg/HgO） was 1.42 times higher than that of Pd/C electrode catalyst. In addition, the relationship between the catalytic stability for MEO on Pd@Ru/C catalysts and the value of dbp/dfp （the ratio of MEO peak current density in the negative scan and positive scan） were also investigated. The result demonstrated that Pd@Rus/C offering the smallest value of Jbp/Jfp displayed the best stable catalytic performance.
