Support , for catalytic

In the sixties of past century, a few patents issued to Bergbau Chemie [5,48,49] and to Mobil Oil [50-52], respectively described the use of CFPs as supports for catalytically active metal nanoclusters and as carriers for heterogenized metal complexes of catalytic relevance. For the latter catalysts the term hybrid phase catalysts later came into use [53,54], At that time coordination chemistry and organo-transition metal chemistry were in full development. Homogeneous transition metal catalysis was expected to grow in industrial relevance [54], but catalyst separation was generally a major problem for continuous processing. That is why the concept of hybrid catalysis became very popular in a short time [55]. 

Cross-linked functional polymers appear to be suitable supports for catalytically active metal(O) nanoclusters. 

A wide range of polymeric materials can be prepared from HIPEs. Polymerisation of the continuous phase yields highly porous cellular polymers with a monolithic structure. These are known as PolyHIPE polymers, and possess a number of unique properties including, in most cases, an interconnected cellular structure and a very low dry-bulk density. Their very high porosity favours their use as supports for catalytic species, precursors for porous carbons and inert matrices for the immobilisation of enzymes and micro-organisms. 

H4SiMo12O40 on the support for catalytic oxidation of methanol (184). At coverages larger than 0.25 monolayer, the selectivities remain constant dimethyl ether is the main product (about 80%), showing the acidic character of the catalyst. Below 0.25 monolayer, the acidic character is lowered, and dimethyl ether rapidly disappears. 

For the cases when efficient mixing has to be coupled with a solid-catalyzed reaction a whole family of open-crossflow-structure catalysts has been developed. The best known of them are the so-called KATAPAK s, commercialized by Sulzer. One of them, KATAPAK-M is shown in Figure 10. It has good mixing properties and can simultaneously be used as the support for catalytic material. 

One major advantage of silica xerogel over other support materials is the ease of adjustment and control of mean pore diameter, specific surface area and the specific pore volume. Supports for catalytic applica-... 

In type a., the separating zeolite layer is equipped with catalytic sites (Bronsted add sites, Lewis acid sites (cations, special Al-sites), metal clusters, catalytic complexes). In type b., the non-supported side of the zeolite layer serves as a support for catalytic entities, e.g. metal crystallites. In type c., zeolite crystals with catalytic power are embedded in a matrix, e.g. a polymer membrane. 

K. Sekizawa, M Machida, K Eguchi, and H Arai, Catalytic properties of Pd-supported hexaaluminate catalysts for high temperature catalytic combustion, J Catal 142 655 (1993) M Machida, K Eguchi, and H Arai, Effect of additives on the surface area of oxide supports for catalytic combustion, J Catal 103 385 (1987)... 

Uranium trioxide is a key precursor to UF4 and UFg, which are used in the isotopic enrichment of nuclear fuels. It is also used in the production of UO2 fuel, and microspheres of UO3 can themselves be used as nuclear fuel. Fabrication of UO3 microspheres has been accomplished using sol-gel or internal gelation processes.Finally, UO3 is also a support for catalytic oxidative destructive of organics. 

Aluminas are extensively used as catalysis and supports for catalytic materials. It is well known that the surface chemistry of adatoms may be influenced profoundly by addition on the alumina of minute amounts of electropositive or electronegative ions like alkalies or halogens (ref 1), Asa result the catalytic action of the active surface phase appears modified (refs 2-5), Such modiftcation may be due to (1) modified symmetry of the active sites, (2) different degree of dispersion of sites, or (3) altered surface coverage (refs. 6-9). Additives absorbed on the active sites of alumina may act as poisons. Such a poisoning action cun be expressed in formal terms, as a function of the concentration of added modifier. 

Ionic liquids (ILs), beside affording new molecular supports for catalytically active species, are entering the field of organocatalysis as solvent by offering (i) a new medium for checking the performance of existing organocatalysis in... 

Temperature resistant oxide supports for catalytic active phases are necessary for the catalytic combustion of hydrocarbon pollutants in the field of environment as well for energy production through hydrocarbon clean combustion. Four commonly used pure support oxides in catalysis silica, alumina, titania, and zirconia were synthesised by the sol-gel and aerogel methods and, in parallel, the same oxides were doped with yttria. Pure yttria aerogel was also made and characterised. Heat treatments were performed from ambient up to 1200°C and BET surface areas and XRD patterns were recorded after heat treatments at 300, 600, 900 and 1200 °C for pure and doped oxides, respectively. 

A thin porous layer of alumina on a metal surface can be created by high-temperature treatment of aluminum-containing steel (e.g., DIN 1.4767, FeCrAl). By heating the alloy for several hours to 800-1000 °C, a thin, well-adhering alumina film of thickness 1- 5 pm is formed on the "FeCrAl alloy" surface [159,160]. This alumina film can be used as a support for catalytically active metal species as shown by Aartun et al. [161,162] or as a foundation on which subsequently deposited, thicker layers will strongly adhere [163,164], The mechanism of layer formation during thermal treatment in air has been investigated in detail by Camra et al. [165]. 

B. Kucharczyk, W. Tylus, L. Kepinski, Pd-based monolithic catalysts on metal supports for catalytic combustion of methane, Appl. Catal. B-Environ. 49 (2004) 27. 

The linear relationship between perimeter length and activity of Pt/ZrOi indicates the importance of the support for catalytic activity. We believe that the activation of CO2 occurs on the support at the Pt-Zr02 perimeter (as carbonates) which is followed by the reaction of the activated carbonate with methane to... 

Zeolites are crystalline aluminosiHcates. Their unit cells are quite complex, as they have intricate microporous structures. Currently, around 200 frameworks are known for zeolites [10], and they all have one specific characteristic chaimels and pores in the size range 2 A to 1 nm, incorporated into the framework structure. This characteristic makes them appropriate for use as, for example, molecular sieves, cation-exchange materials, supports for catalytic active phases, and catalysts themselves [11, 12]. Controlled synthesis of zeoHte materials is still a challenge, and in this regard only a few selected zeolites have been studied in detail [13]. Silicalite-1 (MFI framework) has a pure-silica stmcture, but does not have active sites. The incorporation of, for example, heteroatoms such as aluminum (ZSM-5) makes it catalytically active [14, 15]. Nevertheless, silicalite-1 can be seen as an archetype system, of which its preparation has been characterized in great detail. 

Cano, M. Benito, A. M. Urriolabeitia, E. R Arenal, R. Maser, W. K., Reduced Graphene Oxide Firm Support for Catalytically Active Palladium Nanoparticles and Game Changer in Selective Hydrogenation Reactions. Nanoscale 2013,5 (21), 10189-10193. 

Sensors for tough conditions conductometric gas sensors support for catalytic gas sensors electronic nose electrodes for high-temperature electrochemical sensors pH sensors humidity sensors optical sensors capacitance sensors Conductometric sensors FET sensors sensors for microenvironments... 

As already outlined, mixed metal oxide films and powders play important roles as sensors, catalysts and as supports for catalytically active species. In particular, iron oxide doped silica find application in catalytic processes like Friedel-Crafts alkylation, the conversion of CH4 to HCHO and in the decomposition of methanol and phenol [175]. 

Many unit operations in a chemical process involve a fluid flowing through a circular column filled with material particles. The material particles can be a porous solid or a structured packing. We use porous solids as adsorbents to remove process poisons from process feed streams or to remove contaminant from product prior to selling it. We also use porous solids as support for catalytic metals, which we use in fixed-bed reactors. We use structured packing in any process... 

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