10 research outputs found

    Metal-ceramic composites for photocatalytic oxidation of diclofenac in aqueous solution

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    Photocatalytic activity of metal‐ceramic composites synthesized by self‐propagating high‐temperature synthesis (SHS) is investigated in the processes of degradation of diclofenac (DCF). Optical properties of the composites were studied, and the band gaps of ceramic matrix semiconducting components were calculated from the absorbance spectra. The effect of the phase composition, UV irradiation duration, the nature and quantity of the activator (H2C2O4 and H2O2) on the degree of oxidation destruction was investigated. The best catalytic performance (98–99 % DCF degradation) was achieved with the combination of heterogeneous boron nitride and SiAlON based composites and a homogeneous photo‐Fenton system. However, DCF decomposition with a minimum number of intermediates was achieved using boron nitride‐based composites. Effective degradation of diclofenac in water! Iron‐containing composites capable of absorbing UV radiation and creating conditions in the presence of hydrogen peroxide and oxalic acid for homogeneous photocatalysis are proposed. Deep degradation occurs with simultaneous oxidative destruction processes of diclofenac according to the principle of heterogeneous and homogeneous photocatalysis

    Challenges in the Greener Production of Formates/Formic Acid, Methanol, and DME by Heterogeneously Catalyzed CO2 Hydrogenation Processes

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    The recent advances in the development of heterogeneous catalysts and processes for the direct hydrogenation of CO2 to formate/formic acid, methanol, and dimethyl ether are thoroughly reviewed, with special emphasis on thermodynamics and catalyst design considerations. After introducing the main motivation for the development of such processes, we first summarize the most important aspects of CO2 capture and green routes to produce H2. Once the scene in terms of feedstocks is introduced, we carefully summarize the state of the art in the development of heterogeneous catalysts for these important hydrogenation reactions. Finally, in an attempt to give an order of magnitude regarding CO2 valorization, we critically assess economical aspects of the production of methanol and DME and outline future research and development directions

    Cover picture: Shaping covalent triazine frameworks for the hydrogenation of Carbon Dioxide to Formic Acid (ChemCatChem 13/2016)

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    The Front Cover shows a formation of covalent triazine framework (CTF) based spheres using commercially available polyimide as a binder. In their Full Paper, A. V. Bavykina et al. present a facile one‐step method to shape CTFs into composite spheres with accessible porosity, high mechanical, and thermal stability. They used the fabricated spheres to host organometallic IrIII complex and obtained a catalyst, which is active and fully recyclable in the direct hydrogenation of carbon dioxide into formic acid. More information can be found in the Full Paper by A. V. Bavykina et al. on page 2217 in Issue 13

    Shaping covalent triazine framework for the hydrogenation of carbon dioxide to formic acid

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    The front cover artwork for Issue 13/2016 is provided by researchers from the Catalysis Engineering group, Chemical Engineering Department, Delft University of Technology (The Netherlands). The image shows the formation of covalent triazine framework (CTF) based spheres by using commercially available polyimide as a binder. See the Full Paper itself at http://dx.doi.org/10.1002/cctc.201600419

    Molecular-Scale Hybrid Membranes Derived from Metal-Organic Polyhedra for Gas Separation

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    The preparation and the performance of mixed matrix membranes based on metal-organic polyhedra (MOPs) are reported. MOP fillers can be dispersed as discrete molecular units (average 9 nm in diameter) when low filler cargos are used. In spite of the low doping amount (1.6 wt %), a large performance enhancement in permeability, aging resistance, and selectivity can be achieved. We rationalize this effect on the basis of the large surface to volume ratio of the filler, which leads to excellent dispersion at low concentrations and thus alters polymer packing. Although membranes based only on the polymer component age quickly with time, the performance of the resulting MOP-containing membranes meets the commercial target for postcombustion CO<sub>2</sub> capture for more than 100 days

    Facile Method for the Preparation of Covalent Triazine Framework coated Monoliths as Catalyst Support: Applications in C1 Catalysis

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    A quasi chemical vapor deposition method for the manufacture of well-defined covalent triazine framework (CTF) coatings on cordierite monoliths is reported. The resulting supported porous organic polymer is an excellent support for the immobilization of two different homogeneous catalysts: (1) an Ir<sup>III</sup>Cp*-based catalyst for the hydrogen production from formic acid and (2) a Pt<sup>II</sup>-based catalyst for the direct activation of methane via Periana chemistry. The immobilized catalysts display a much higher activity in comparison with the unsupported CTF operated in slurry because of improved mass transport. Our results demonstrate that CTF-based catalysts can be further optimized by engineering at different length scales

    Challenges in the Greener Production of Formates/Formic Acid, Methanol, and DME by Heterogeneously Catalyzed CO2 Hydrogenation Processes

    No full text
    The recent advances in the development of heterogeneous catalysts and processes for the direct hydrogenation of CO2 to formate/formic acid, methanol, and dimethyl ether are thoroughly reviewed, with special emphasis on thermodynamics and catalyst design considerations. After introducing the main motivation for the development of such processes, we first summarize the most important aspects of CO2 capture and green routes to produce H2. Once the scene in terms of feedstocks is introduced, we carefully summarize the state of the art in the development of heterogeneous catalysts for these important hydrogenation reactions. Finally, in an attempt to give an order of magnitude regarding CO2 valorization, we critically assess economical aspects of the production of methanol and DME and outline future research and development directions.ChemE/Catalysis Engineerin
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