Platinum and palladium nanoparticles in modified mesoporous phenol—formaldehyde polymers as hydrogenation catalysts
TL;DR: In this paper, mesoporous polymeric supports modified with sulfo groups and PPI dendrimers have been used for the hydrogenation of phenylacetylene and naphthalene at temperatures of 80 and 400°C.
Abstract: Mesoporous polymeric supports modified with sulfo groups and PPI dendrimers have been prepared. Catalysts containing palladium and platinum nanoparticles have been synthesized on their basis. The resulting catalysts have been studied by transmission electron microscopy and X-ray photoelectron spectroscopy. It has been shown that the metal deposition procedure has an effect on the morphology of the resulting catalyst. Catalytic activity has been studied using the example of the hydrogenation of phenylacetylene and naphthalene at temperatures of 80 and 400°C, and pressures of 1.0 and 5.0 MPa, respectively.
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TL;DR: In this paper, an easily manufactured catalyst, alkali-metal-promoted Pd/TiO2, achieves 99% phenol conversion and 99% cyclohexanone selectivity at mild conditions of 80 °C and an extremely low H2 pressure of 0.06 MPa in water.
83 citations
TL;DR: In this paper, a mesoporous phenolsulfonic acid-formaldehyde polymeric acid catalyst was synthesized simply by condensation polymerization of p-phenols sulfuronic acid and an aqueous solution of formaldehyde.
Abstract: A mesoporous phenolsulfonic acid–formaldehyde polymeric acid catalyst was synthesized simply by condensation polymerization of p-phenolsulfonic acid and an aqueous solution of formaldehyde. The acid-functionalized polymer was used as a heterogeneous catalyst for glycerol acetalization with acetone for synthesis of solketal without the requirement of water removal from the reaction mixture. Solketal is extensively used as an additive for the formulation of petrol, diesel, and biodiesel. The effect of reaction parameters, such as the reaction temperature, time, catalyst loading, and glycerol/acetone molar ratio, on the glycerol conversion was exhaustively investigated in detail. Glycerol conversion of 97% and product selectivity of 100% were attained under the optimized reaction conditions: time of 4 h, temperature of 60 °C, catalyst loading of 8 wt %, and glycerol/acetone ratio of 5:1. Recycling of the used catalyst revealed good repeatability without any reactivation until the fourth cycle with a minimal ...
40 citations
TL;DR: In this paper, a new class of carbon supports with a diamond-like ordered structure has been synthesized for the hydrogenation of unsaturated hydrocarbons, based on palladium and platinum nanoparticles immobilized in pores of mesoporous aromatic frameworks.
Abstract: Heterogeneous catalysts for the hydrogenation of unsaturated hydrocarbons have been synthesized on the basis of palladium and platinum nanoparticles immobilized in pores of mesoporous aromatic frameworks, which represent a new class of carbon supports with a diamond-like ordered structure. The resulting materials have been characterized by transmission electron microscopy, IR spectroscopy, and NMR spectroscopy. It has been shown that the catalyst activity in the hydrogenation reaction depends on the substrate molecule size and adsorbability on the surface of nanoparticles. Catalytic activity has been studied in the hydrogenation of a number of unsaturated compounds at temperatures of 60 and 80°C and pressures of 1.0 and 3.0 MPa.
14 citations
TL;DR: In this article, Ni-W sulfide catalysts for the synthesis of aromatic hydrocarbons were synthesized by the in situ decomposition of tetrabutylammonium nickel thiotungstate complex supported on ordered mesoporous phenol-formaldehyde polymer.
Abstract: Ni–W sulfide catalysts for the hydroprocessing of aromatic hydrocarbons were synthesized by the in situ decomposition of tetrabutylammonium nickel thiotungstate complex supported on ordered mesoporous phenol–formaldehyde polymer. Catalysts obtained with and without additional sulfidation with dimethyl disulfide were characterized by X-ray photoelectron spectroscopy and transmission electron microscopy. The catalytic activity has been studied using naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, and anthracene as examples. It is shown that the system used in this study proved to be active in hydrogenation and hydrocracking of polyaromatic hydrocarbons.
12 citations
Abstract: Abstract The paper concerns application of two types of organic materials – porous aromatic frameworks (PAFs) with diamond-like structure and the ordered mesoporous phenol-formaldehyde polymers (MPFs) – as supports for metal and metal sulfide nanoparticles. The obtained hybrid materials were tested in hydrogenation of various unsaturated and aromatic compounds. Ruthenium catalyst, based on PAF (Ru-PAF-30), possessed high activity in exhaustive hydrogenation of phenol into cyclohexanol with TOF value of 2700 h−1. Platinum catalyst, based on modified with sulfo-groups MPF (MPF-SO3H-Pt), was selective in semi-hydrogenation of terpenes, [α-terpinene, γ-terpinene, terpinolene, (s)-limonene]. Bimetallic Ni–W sulfide catalysts, prepared by in situ decomposition of [(n-Bu)4N]2Ni(WS4)2 within the pores of MPFs and PAFs, possessed high efficiency in hydrogenation-hydrocracking of naphthalenes as model substrates.
11 citations
References
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TL;DR: Use of amphiphilic triblock copolymers to direct the organization of polymerizing silica species has resulted in the preparation of well-ordered hexagonal mesoporous silica structures (SBA-15) with uniform pore sizes up to approximately 300 angstroms.
Abstract: Use of amphiphilic triblock copolymers to direct the organization of polymerizing silica species has resulted in the preparation of well-ordered hexagonal mesoporous silica structures (SBA-15) with uniform pore sizes up to approximately 300 angstroms. The SBA-15 materials are synthesized in acidic media to produce highly ordered, two-dimensional hexagonal (space group p6mm) silica-block copolymer mesophases. Calcination at 500°C gives porous structures with unusually large interlattice d spacings of 74.5 to 320 angstroms between the (100) planes, pore sizes from 46 to 300 angstroms, pore volume fractions up to 0.85, and silica wall thicknesses of 31 to 64 angstroms. SBA-15 can be readily prepared over a wide range of uniform pore sizes and pore wall thicknesses at low temperature (35° to 80°C), using a variety of poly(alkylene oxide) triblock copolymers and by the addition of cosolvent organic molecules. The block copolymer species can be recovered for reuse by solvent extraction with ethanol or removed by heating at 140°C for 3 hours, in both cases, yielding a product that is thermally stable in boiling water.
10,807 citations
10 Jul 1997
TL;DR: This paper presents a meta-modelling system that automates the very labor-intensive and therefore time-heavy and therefore expensive and expensive process of characterization and activation of Solid Catalysts.
Abstract: Preparation of Solid Catalysts. Characterization of Solid Catalysts. Model Systems. Elementary Steps and Mechanisms. Kinetics and Transport Processes. Deactivation and Regeneration. Special Catalytic Systems. Laboratory Reactors. Reaction Engineering. Environmental Catalysis. Inorganic Reactions. Energy-related Catalysis. Organic Reactions.
4,227 citations
Book•
01 Nov 1992
TL;DR: In this article, the binding energy scale for sample charging curve fitting lineshapes shake-up structure valence bands impurities x-ray degradation organization of the database list of polymers and acronyms the database appendix 1 - primary C 1s shifts appendix 2 - secondary C 1 s shifts appendix 3.1 - 0 1s binding energies in CHO polymers appendix 4 - N 1 s binding energies appendix 5 - F 1 S binding energies and spin-orbit constants for core-line doublets apendix 7 - binding energies of peaks appearing in the valence band region
Abstract: Description of the spectrometer x-ray source monochromator electron lens hemispherical analyser multichannel detector sample analysis chamber charge compensation performance on conducting samples performance on insulating samples performance on testing of the spectrometer experimental protocol sample mounting data acquisition correction of binding energy scale for sample charging curve fitting lineshapes shake-up structure valence bands impurities x-ray degradation organization of the database list of polymers and acronyms the database appendix 1 - primary C 1s shifts appendix 2 - secondary C 1s shifts appendix 3.1 - 0 1s binding energies in CHO polymers appendix 3.2 - 0 1s binding energies in other polymers appendix 4 - N 1s binding energies appendix 5 - F 1s binding energies appendix 6 - binding energies and spin-orbit constants for core-line doublets apendix 7 - binding energies of peaks appearing in the valence band region.
2,395 citations
TL;DR: Intradendrimer hydrogenation and carbon-carbon coupling reactions in water, organic solvents, biphasic fluorous/organic solvent, and supercritical CO2 are also described.
Abstract: This Account reports the synthesis and characterization of dendrimer-encapsulated metal nanoparticles and their applications to catalysis. These materials are prepared by sequestering metal ions within dendrimers followed by chemical reduction to yield the corresponding zerovalent metal nanoparticle. The size of such particles depends on the number of metal ions initially loaded into the dendrimer. Intradendrimer hydrogenation and carbon−carbon coupling reactions in water, organic solvents, biphasic fluorous/organic solvents, and supercritical CO2 are also described.
1,925 citations
TL;DR: In this paper, the synthesis of mesoporous polymers and carbon frameworks from organic−organic assembly of triblock copolymers with soluble, low-molecular-weight phenolic resin precursors (resols) by an evaporation induced self-assembly strategy has been reported.
Abstract: The syntheses of a family of highly ordered mesoporous polymers and carbon frameworks from organic−organic assembly of triblock copolymers with soluble, low-molecular-weight phenolic resin precursors (resols) by an evaporation induced self-assembly strategy have been reported in detail. The family members include two-dimensional hexagonal (space group, p6m), three-dimensional bicontinuous (Ia3d), body-centered cubic (Im3m), and lamellar mesostructures, which are controlled by simply adjusting the ratio of phenol/template or poly(ethylene oxide)/poly(propylene oxide) in the templates. A five-step mechanism from organic−organic assembly has been demonstrated. Cubic FDU-14 with a gyroidal mesostructure of polymer resin or carbon has been synthesized for the first time by using the copolymer Pluronic P123 as a template in a relatively narrow range. Upon calcination at 350 °C, the templates should be removed to obtain mesoporous polymers, and further heating at above a critical temperature of 600 °C transfor...
1,013 citations