Metal-organic-framework (MOF)-based materials with novel physicochemical properties have emerged as promising catalysts for various hydrogenation reactions. In addition to metal clusters and multifunctional organic...Metal-organic-framework (MOF)-based materials with novel physicochemical properties have emerged as promising catalysts for various hydrogenation reactions. In addition to metal clusters and multifunctional organic ligands, MOF-based catalysts can incorporate other functional species, and thus provide various active sites for hydrogenation processes. The structural properties of the catalysts play significant roles in enhancing the interactions among the reactants, products, and catalytic sites, which can be rationally designed. Because of the synergistic effects between the ac-tive sites and the structural properties, MOF-based catalysts can achieve higher activities and selec- tivities in hydrogenation reactions than can be obtained using traditional heterogeneous catalysts. This review provides an overview of recent developments in MOF-based catalysts in the hydro-genation of alkenes, alkynes, nitroarenes, cinnamaldehyde, furfural, benzene, and other compounds. Strategies for improving the catalytic performances of MOF-based catalysts are discussed as well as the different active sites and structural properties of the catalysts.展开更多
An efficient and highly chemoselective heterogeneous catalyst system for quinoline hydrogenation was developed using unsupported nanoporous palladium(PdNPore).The PdNPore‐catalyzed chemoselective hydrogenation of qui...An efficient and highly chemoselective heterogeneous catalyst system for quinoline hydrogenation was developed using unsupported nanoporous palladium(PdNPore).The PdNPore‐catalyzed chemoselective hydrogenation of quinoline proceeded smoothly under mild reaction conditions(low H2 pressure and temperature)to yield 1,2,3,4‐tetrahydroquinolines(py‐THQs)in satisfactory to excellent yields.Various synthetically useful functional groups,such as halogen,hydroxyl,formyl,ethoxycarbonyl,and aminocarbonyl groups,remained intact during the quinoline hydrogenation.No palladium was leached from PdNPore during the hydrogenation reaction.Moreover,the catalyst was easily recovered and reused without any loss of catalytic activity.The results of kinetic,deuterium‐hydrogen exchange,and deuterium‐labeling experiments indicated that the present hydrogenation involves heterolytic H2 splitting on the surface of the catalyst.展开更多
TiO2 fibers were prepared via alternatively introducing water vapor and Ti precursor carried by N2 to an APCVD (chemical vapor deposition under atmospheric pressure) reactor at ≤200 ℃. Activated carbon fibers (A...TiO2 fibers were prepared via alternatively introducing water vapor and Ti precursor carried by N2 to an APCVD (chemical vapor deposition under atmospheric pressure) reactor at ≤200 ℃. Activated carbon fibers (ACFs) were used as templates for deposition and later removed by calcinations. The obtained catalysts were characterized by scanning electron micros- copy (SEM), transmission electron microscopy (TEM), Brunauer, Emmett and Teller (BET) and X-ray diffraction (XRD) analysis The pores within TiO2 fibers included micro-range and meso-range, e.g., 7 nm, and the specific surface areas for TiO2 fibers were 141 m^2/g and 148 m^2/g for samples deposited at 100 ℃ and 200℃ (using ACFI700 as template), respectively. The deposition temperature significantly influenced TiO2 morphology. The special advantages of this technique for preparing porous nano-material include no consumption of organic solvent in the process and easy control of deposition conditions and speeds.展开更多
1. Introduction Zeolites are widely used in acid heterogeneous catalysis [1, 2]. Due to the unique physical and chemical properties ofzeolites, they are widely used in commercial catalytic processes, such as fluidized...1. Introduction Zeolites are widely used in acid heterogeneous catalysis [1, 2]. Due to the unique physical and chemical properties ofzeolites, they are widely used in commercial catalytic processes, such as fluidized catalytic cracking, hydrocracking, methanol conversion to gasoline or olefins, ethylbenzene production, xylene isomerization, aromatics hydrogenation [3-9]. Acidity, high thermal stability, and shape selectivity determine the use of zeolites as catalysts in reaction processes through acid mechanisms [ 10].展开更多
基金supported by the National Natural Science Foundation of China(21322606,21436005,21576095)China Postdoctoral Science Foundation(2016M590771)Guangdong Natural Science Foundation(2016A030310413,2013B090500027,2014A030310445,2016A050502004)~~
文摘Metal-organic-framework (MOF)-based materials with novel physicochemical properties have emerged as promising catalysts for various hydrogenation reactions. In addition to metal clusters and multifunctional organic ligands, MOF-based catalysts can incorporate other functional species, and thus provide various active sites for hydrogenation processes. The structural properties of the catalysts play significant roles in enhancing the interactions among the reactants, products, and catalytic sites, which can be rationally designed. Because of the synergistic effects between the ac-tive sites and the structural properties, MOF-based catalysts can achieve higher activities and selec- tivities in hydrogenation reactions than can be obtained using traditional heterogeneous catalysts. This review provides an overview of recent developments in MOF-based catalysts in the hydro-genation of alkenes, alkynes, nitroarenes, cinnamaldehyde, furfural, benzene, and other compounds. Strategies for improving the catalytic performances of MOF-based catalysts are discussed as well as the different active sites and structural properties of the catalysts.
基金supported by the National Natural Science Foundation of China(21573032,21773021)the Fundamental Research Funds for the Central Universities(DUT17ZD212)the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP#0048~~
文摘An efficient and highly chemoselective heterogeneous catalyst system for quinoline hydrogenation was developed using unsupported nanoporous palladium(PdNPore).The PdNPore‐catalyzed chemoselective hydrogenation of quinoline proceeded smoothly under mild reaction conditions(low H2 pressure and temperature)to yield 1,2,3,4‐tetrahydroquinolines(py‐THQs)in satisfactory to excellent yields.Various synthetically useful functional groups,such as halogen,hydroxyl,formyl,ethoxycarbonyl,and aminocarbonyl groups,remained intact during the quinoline hydrogenation.No palladium was leached from PdNPore during the hydrogenation reaction.Moreover,the catalyst was easily recovered and reused without any loss of catalytic activity.The results of kinetic,deuterium‐hydrogen exchange,and deuterium‐labeling experiments indicated that the present hydrogenation involves heterolytic H2 splitting on the surface of the catalyst.
基金Project (No. 20477006) supported by the National Natural ScienceFoundation of China
文摘TiO2 fibers were prepared via alternatively introducing water vapor and Ti precursor carried by N2 to an APCVD (chemical vapor deposition under atmospheric pressure) reactor at ≤200 ℃. Activated carbon fibers (ACFs) were used as templates for deposition and later removed by calcinations. The obtained catalysts were characterized by scanning electron micros- copy (SEM), transmission electron microscopy (TEM), Brunauer, Emmett and Teller (BET) and X-ray diffraction (XRD) analysis The pores within TiO2 fibers included micro-range and meso-range, e.g., 7 nm, and the specific surface areas for TiO2 fibers were 141 m^2/g and 148 m^2/g for samples deposited at 100 ℃ and 200℃ (using ACFI700 as template), respectively. The deposition temperature significantly influenced TiO2 morphology. The special advantages of this technique for preparing porous nano-material include no consumption of organic solvent in the process and easy control of deposition conditions and speeds.
文摘1. Introduction Zeolites are widely used in acid heterogeneous catalysis [1, 2]. Due to the unique physical and chemical properties ofzeolites, they are widely used in commercial catalytic processes, such as fluidized catalytic cracking, hydrocracking, methanol conversion to gasoline or olefins, ethylbenzene production, xylene isomerization, aromatics hydrogenation [3-9]. Acidity, high thermal stability, and shape selectivity determine the use of zeolites as catalysts in reaction processes through acid mechanisms [ 10].