Selective phenol hydrogenation to cyclohexanone over alkali–metal-promoted Pd/TiO2 in aqueous media

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 ...

Acid-Functionalized Mesoporous Polymer-Catalyzed Acetalization of Glycerol to Solketal, a Potential Fuel Additive under Solvent-Free Conditions

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.

Unsaturated-compound hydrogenation nanocatalysts based on palladium and platinum particles immobilized in pores of mesoporous aromatic frameworks

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.

Hydroprocessing of Aromatics Using Sulfide Catalysts Supported on Ordered Mesoporous Phenol–Formaldehyde Polymers

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.

Mesoporous organo-inorganic hybrid materials as hydrogenation catalysts

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.

A. A. Kurmaeva

Papers

Platinum and palladium nanoparticles in modified mesoporous phenol—formaldehyde polymers as hydrogenation catalysts