Ni@Pd core-shell nanoparticles with a mean particle size of 8–9 nm were prepared by solvothermal reduction of bivalent nickel and palladium in oleylamine and trioctylphosphine.Subsequently,the first-ever deposition o...Ni@Pd core-shell nanoparticles with a mean particle size of 8–9 nm were prepared by solvothermal reduction of bivalent nickel and palladium in oleylamine and trioctylphosphine.Subsequently,the first-ever deposition of Ni@Pd core-shell nanoparticles having different compositions on a metal-organic framework（MIL-101）was accomplished by wet impregnation in n-hexane.The Ni@Pd/MIL-101 materials were characterized by powder X-ray diffraction,Fourier transform infrared spectroscopy,transmission electron microscopy,and energy-dispersive X-ray spectroscopy and also investigated as catalysts for the hydrogenation of nitrobenzene under mild reaction conditions.At 30 °C and 0.1 MPa of H2 pressure,the Ni@Pd/MIL-101 gives a TOF as high as 375 h–1 for the hydrogenation of nitrobenzene and is applicable to a wide range of substituted nitroarenes.The exceptional performance of this catalyst is believed to result from the significant Ni-Pd interaction in the core-shell structure,together with promotion of the conversions of aromatics by uncoordinated Lewis acidic Cr sites on the MIL-101 support.展开更多
An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a support.The catalyst with Pt content as low as 0.2 wt%exhibits high activities,c...An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a support.The catalyst with Pt content as low as 0.2 wt%exhibits high activities,chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of niroarenes.The conversion of nitrobenzene can reach 3170 molconv h^–1 molPt^–1 under mild conditions(30°C,5 bar),which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction conditions.The spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity,which decreases the contact possibility between the reducible groups of nitroarenes and Pt nanoparticles.The unique surface properties ofα-Fe2O3 play an important role in the reaction process.It provides active sites for hydrogen spillover and reactant adsorption,and ultimately completes the hydrogenation of the nitro group on the catalyst surface.展开更多
基金supported by the National Natural Science Foundation of China(21322606 and 21436005)the Specialized Research Fund for the Doctoral Program of Higher Education(20120172110012)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Natural Science Foundation of Guangdong Province(S2011020002397 and 2013B090500027)~~
文摘Ni@Pd core-shell nanoparticles with a mean particle size of 8–9 nm were prepared by solvothermal reduction of bivalent nickel and palladium in oleylamine and trioctylphosphine.Subsequently,the first-ever deposition of Ni@Pd core-shell nanoparticles having different compositions on a metal-organic framework（MIL-101）was accomplished by wet impregnation in n-hexane.The Ni@Pd/MIL-101 materials were characterized by powder X-ray diffraction,Fourier transform infrared spectroscopy,transmission electron microscopy,and energy-dispersive X-ray spectroscopy and also investigated as catalysts for the hydrogenation of nitrobenzene under mild reaction conditions.At 30 °C and 0.1 MPa of H2 pressure,the Ni@Pd/MIL-101 gives a TOF as high as 375 h–1 for the hydrogenation of nitrobenzene and is applicable to a wide range of substituted nitroarenes.The exceptional performance of this catalyst is believed to result from the significant Ni-Pd interaction in the core-shell structure,together with promotion of the conversions of aromatics by uncoordinated Lewis acidic Cr sites on the MIL-101 support.
基金supported by the National Natural Science Foundation of China(21473073,21473074)‘‘13th Five-Year’’ Science and Technology Research of the Education Department of Jilin Province(2016403)+1 种基金the Development Project of Science and Technology of Jilin Province(20170101171JC,20180201068SF)the Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(201703)~~
文摘An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a support.The catalyst with Pt content as low as 0.2 wt%exhibits high activities,chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of niroarenes.The conversion of nitrobenzene can reach 3170 molconv h^–1 molPt^–1 under mild conditions(30°C,5 bar),which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction conditions.The spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity,which decreases the contact possibility between the reducible groups of nitroarenes and Pt nanoparticles.The unique surface properties ofα-Fe2O3 play an important role in the reaction process.It provides active sites for hydrogen spillover and reactant adsorption,and ultimately completes the hydrogenation of the nitro group on the catalyst surface.
