A hierarchical microporous-mesoporous metal-organic framework of HKUST-l（Cu）-encapsulated phosphotungstic acid （HPW） material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cety...A hierarchical microporous-mesoporous metal-organic framework of HKUST-l（Cu）-encapsulated phosphotungstic acid （HPW） material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cetyltrimethylammonium bromide as the supramolecular template. The addition of HPWs to the synthesis mixture of hierarchical porous HKUST-1 results in the direct encapsulation of HPWs inside the mesopores of the HKUST-1 structure, with a homogeneous distribution over the HKUST-1 crystals, which is confirmed by XRD, FT-IR, N2 adsorption, UV-Vis DRS, and TEM. FT-IR-CO adsorption experiments indicated that additional Lewis acid sites were present in the HPWs@Meso-HKUST-1 sample. The novel heterogeneous catalyst demonstrates excellent catalytic performance for the selective oxidation of cyclopentene （CPE） to glutaraldehyde CGA） using tert-butyl hydroperoxide and acetonitrile （MeCN） as the oxidant and solvent, respectively. The high activity of the catalyst is attributed to the mesostructure of the catalyst and the nature and appropriate abundance of the HPWs--being highly dispersed with the addition of Lewis sites. After a reaction for 36 h, the 30% wt% HPWs@Meso-HKUST-1 catalyst exhibits a CPE conversion of 92.5% and a high GA yield of 73%. Furthermore, the HPWs@Meso-HKUST-1 material is sufficiently stable to prevent the leaching of HPWs, and behaves as a true heterogeneous catalyst that can be repeatedly recycled without sustaining a loss of activity and selectivity in the selective oxidation of CPE.展开更多
A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H3P...A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H3PW12O40/MCM-48 was studied with butyraldehyde and glycol as reactants. H3PW12O40/MCM-48 was an excellent catalyst for the synthesizing butyraldehyde glycol acetal and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n（butyraldehyde）： n（glycol）, catalyst dosage, cyclohexane（water-stripped reagent） and reaction time on yields of the product were investigated. The optimum conditions had been found, that was, molar ratio of butyraldehyde to glycol was 1： 1.6, mass ratio of catalyst used to the reactants was 0.25% and reaction time was 75 min. Under these conditions, the yield of butyraldehyde glycol acetal can reach 79.74%.展开更多
基金supported by the Plan of Nature Science Fundamental Research in Henan University of Technology (2013JCYJ09)the Fundamental Research Funds for the Henan Provincial Colleges and Universities(2014YWQQ13)the National Natural Science Foundation of China (20903035,21373054)~~
文摘A hierarchical microporous-mesoporous metal-organic framework of HKUST-l（Cu）-encapsulated phosphotungstic acid （HPW） material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cetyltrimethylammonium bromide as the supramolecular template. The addition of HPWs to the synthesis mixture of hierarchical porous HKUST-1 results in the direct encapsulation of HPWs inside the mesopores of the HKUST-1 structure, with a homogeneous distribution over the HKUST-1 crystals, which is confirmed by XRD, FT-IR, N2 adsorption, UV-Vis DRS, and TEM. FT-IR-CO adsorption experiments indicated that additional Lewis acid sites were present in the HPWs@Meso-HKUST-1 sample. The novel heterogeneous catalyst demonstrates excellent catalytic performance for the selective oxidation of cyclopentene （CPE） to glutaraldehyde CGA） using tert-butyl hydroperoxide and acetonitrile （MeCN） as the oxidant and solvent, respectively. The high activity of the catalyst is attributed to the mesostructure of the catalyst and the nature and appropriate abundance of the HPWs--being highly dispersed with the addition of Lewis sites. After a reaction for 36 h, the 30% wt% HPWs@Meso-HKUST-1 catalyst exhibits a CPE conversion of 92.5% and a high GA yield of 73%. Furthermore, the HPWs@Meso-HKUST-1 material is sufficiently stable to prevent the leaching of HPWs, and behaves as a true heterogeneous catalyst that can be repeatedly recycled without sustaining a loss of activity and selectivity in the selective oxidation of CPE.
基金This work was financially supported by the Natural Science Foundation of Hubei Province, China （No. 2005ABA053）.
文摘A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H3PW12O40/MCM-48 was studied with butyraldehyde and glycol as reactants. H3PW12O40/MCM-48 was an excellent catalyst for the synthesizing butyraldehyde glycol acetal and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n（butyraldehyde）： n（glycol）, catalyst dosage, cyclohexane（water-stripped reagent） and reaction time on yields of the product were investigated. The optimum conditions had been found, that was, molar ratio of butyraldehyde to glycol was 1： 1.6, mass ratio of catalyst used to the reactants was 0.25% and reaction time was 75 min. Under these conditions, the yield of butyraldehyde glycol acetal can reach 79.74%.
