10 research outputs found
Metal-ceramic composites for photocatalytic oxidation of diclofenac in aqueous solution
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
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)
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
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
Molecular-Scale Hybrid Membranes Derived from Metal-Organic Polyhedra for Gas Separation
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
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
A Titanium Metal–Organic Framework with Visible‐Light‐Responsive Photocatalytic Activity
Challenges in the Greener Production of Formates/Formic Acid, Methanol, and DME by Heterogeneously Catalyzed CO2 Hydrogenation Processes
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