Microstructured catalysts

Figure 5.13 SEM images of the microstructured catalyst support in the multi-channel reactor version. Overall view (channel view) (A) and detailed view of one column (B) [12],...

Scanning electron micrographs of typical NSTF catalysts as fabricated on a microstructured catalyst transfer substrate, seen (top) in cross section with original magnification of xl0,000 and (bottom) in-plane view with original magnification of x50,000. A dotted scale bar is shown in each micrograph. (Reproduced from Debe, M. K. et al. Journal of Power Sources 2006 161 1002-1011. With permission from Elsevier.)... 

Pfeifer, P., Fichtner, M., Schubert, K., Liauw, M. A., Emig, G., Microstructured catalysts for methanol-steam reforming, in Ehrfeld, W. (Ed.), Microreaction Technology 3rd International Conference on Microreaction Technology, Proc. ofIMRET 3, Springer-Verlag, Berlin, 2000, 372-382. 

G., The water gas shift reaction for automotive applications preparation and testing of microstructured catalysts, in Proceedings of the 7th International Conference on Microreaction Technology, IMRET 7 (7-10 Sept. 2003), Lausanne, 2003, 173-175. 

James Wei Perhaps I don t quite understand your terms. Would you consider a zeolite a microstructure catalyst ... 

Cao, C., Wang, Y., and Rozmiarek, R.T. Heterogeneous reactor model for steam reforming of methane in a microchannel reactor with microstructured catalysts. Catalysis Today, 2005,110 (1—2), 92. 

This chapter primarily covers microstructured reactors (MSRs). Furthermore, the use and the advantages of microstructured catalysts such as fabrics, grids, and foams are discussed. 

Another example is the use of a filamentous microstructured catalyst in a membrane reactor specifically developed for the continuous production of propene from propane via nonoxidative dehydrogenation. The catalytic filaments with a diameter of 7 pm consisted of a silica core covered by a y-Al203 porous layer, which served as a support for an active phase of platinum and tin [53,54]. 

Deposit formation on the electrode occurs via particle coagulation. Electrophoretic migration results in the accumulation of particles and formation of a homogeneous layer at the relevant electrode. The potential of EPD for film formation on various materials and complex shapes is of great interest for the preparation of microstructured catalyst and reactors. A review about electrodeposition of ceramic and organoceramic materials can be found in Ref. [223]. 

Aligned multiwall CNT arrays were synthesized as a basis for a microstructured catalyst, which was then tested in the Fischer-Tropsch reaction in a microchannel reactor [269]. Fabrication of such a structured catalyst first involved MOCVD of a thin but dense A1203 film on a FeCrAlY foam to enhance the adhesion between the catalyst and the metal substrate. Then, multiwall CNTs were deposited uniformly on the substrate by controlled catalytic decomposition of ethene. Coating the outer surfaces of the nanotube bundles with an active catalyst layer results in a unique hierarchical structure with small interstitial spaces between the carbon bundles. The microstructured catalyst was characterized by the excellent thermal conductivity inherent to CNTs, and heat could be efficiently removed from the catalytically active sites during the exothermic Fischer-Tropsch synthesis. 

Phenomena taking place from microscale to macroscale influence olefin polymerization rates and polyolefin microstructure. Catalyst type ultimately determines the polymer microstructure for a given set of polymerization conditions such as temperature, monomer/comonomer ratio, and hydrogen concentration, but the polymerization conditions at the active sites are a consequence of the type of catalyst support and reactor used to produce the polyolefin. 

The co-reduction of the Pt and Ru cations resulted in the formation of the core/shell microstructured catalysts due to the preferential reduction of the Pt cation. In this section, a strategy for synthesizing well-mixed Pt-Ru bimetallic nanoparticle catalysts is presented. A key for the synthesis is decreasing difference of effective reduction potentials between the Pt... 

FIGURE 4-2 SEM images of Pt thin-film catalysts supported on crystalline organic whiskers. Top—cross-section on microstructured catalyst transfer substrate. Bottom—Plainview. Reprinted from Ref. [12], with permission from Elsevier. 

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