Preparation and Catalytic Tests

CatalystFl Temp. (K), pressure (MPa) C3H6/O2/H2/ Carrier, SV (h- ml gca ) C3H6 conversion PO selectivity Hi efficiency POSTY (h gFo kg r ) Ref. 

In the case of Ti-Si02, washing is also crucial. Complete washing is deleterious for maintaining PO selectivity, suggesting that the presence of a small amount of Na and/or Cl are necessary for Au to be selective for the formation of PO [23] (Table 14.2). In the DP method, Au is deposited on Ti sites but not on the surfaces of Si02- This selectivity of Au deposition leads to high selectivity to PO. 

MCM-41 [hexagonal], (b) Ti-MCM-48 [cubic], (c) large mesoporous Ti-Si02 [sponge-likej. 

Washing Au loading Reaction Conversion method (wt%) temp. (K) %) 

Actual Au loading. PO propene oxide, PA propionaldehyde, AT acetone, AA acetaldehyde. Catalyst, 0.5 g feed gas, CjH6/02/H2/Ar = 10/10/10/70 space velocity, 4000h mlgca, .  

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A new composite containing montmorillonite and zeolite Beta was prepared and characterized by XRD, N2 adsorption-desorption, FT-IR, SEM and catalytic testing. It indicates that nano-zeolite Beta grows on montmorillonite, and high diffusion is obtained, due to the abundance of interspace formed in composite. 

Sulfur resistance of PtPd catalysts preparation, characterization and catalytic testing... 

Mn-MCM-41 catalysts were prepared and then tested using the selective catalytic reduction of NO by NH3. The influence of the support (siliceous or aluminosilicate MCM-41) as well as the composition of the gas feed were investigated with respect to the catalytic activity. The pure siliceous MCM-41 seems to offer much better catalytic properties to the catalyst. The presence of a mixture of NO and NO2 in the gas feed causes an increase of SCR activity. The catalysts analysed exhibit fairly high NOx conversion at temperatures above 250°C. 

The solids have been prepared by solid-state reaction in air, of pure V(V), Sb(III) y Ti(IV) oxides. Fresh samples have been characterised by Temperature programmed reduction (TPR) and catalytic tests. For Vo 8SbTio.204 catalysts, elemental C-H-N-O analysis was performed on fresh and used samples. 

Preparation and catalytic performance test of all samples in the generation. 

The Staudinger synthesis is catalysed by NHCs (A -heterocyclic carbenes), via Ye s possible ketene-first or imine-first mechanisms. To test these alternatives, four zwitterionic NHC adducts have been prepared two using A -tosyl benzaldimine and two using diphenylketene. All four adducts had 1 1 stoichiometry and have been extensively characterized by H- and C-NMR, X-ray crystallography and catalytic tests. The imine-derived zwitterions proved poor catalysts, whereas those derived from diphenylketene replicated the free carbene catalysts, strongly supporting the ketene-first route. 

L.A. Boot, 1996, Preparation, characterization and catalytic testing of cobalt oxide and manganese oxide catalysts supported on zirconia, Appl. Catal. A, 137,69-86... 

Catalyst testing and evaluation have been revolutionized by computers, automated test reactors, and analytical methods. With modem equipment, researchers can systematically prepare and screen many catalysts in a short time and efftciendy deterrnine, not only the initial catalytic activity and selectivity, but also the stabiUty and the appearance of trace products that may indicate some new catalytic properties worthy of further development. 

Ghosh et al. [70] reviewed a few years ago the utihty of C2-symmetric chiral bis(oxazoline)-metal complexes for catalytic asymmetric synthesis, and they reserved an important place for Diels-Alder and related transformations. Bis(oxazoline) copper(II)triflate derivatives have been indeed described by Evans et al. as effective catalysts for the asymmetric Diels-Alder reaction [71]. The bis(oxazoline) Ugand 54 allowed the Diels-Alder transformation of two-point binding N-acylimide dienophiles with good yields, good diastereos-electivities (in favor of the endo diastereoisomer) and excellent ee values (up to 99%) [72]. These substrates represent the standard test for new catalysts development. To widen the use of Lewis acidic chiral Cu(ll) complexes, Evans et al. prepared and tested bis(oxazoHnyl)pyridine (PyBOx, structure 55, Scheme 26) as ligand [73]. 

The goal of this work was to prepare and characterize PtRu/MgO catalysts from cluster A which contained Pt-Ru bonds and compare with that prepared from a mixed solution of Pt(acac)2 and Ru(acac)3. The characterization methods included IR and EXAFS spectroscopy. Ethylene hydrogenation was used to test the catalytic activity of both PtRu/MgO catalysts. 

Ir catalysts supported on binary oxides of Ti/Si and Nb/Si were prepared and essayed for the hydrogenation of a,P-unsaturated aldehydes reactions. The results of characterization revealed that monolayers of Ti/Si and Nb/Si allow a high metal distribution with a small size crystallite of Ir. The activity test indicates that the catalytic activity of these solids is dependent on the dispersion obtained and acidity of the solids. For molecules with a ring plane such as furfural and ciimamaldehyde, the adsorption mode can iirfluence the obtained products. SMSI effect (evidenced for H2 chemisorption) favors the formation of unsaturated alcohol. 

To better address the role of Pt in the reduction mechanism, a physical mixture of the binary Pt/y-Al203 and BaAy-A O, samples was also prepared and tested. This catalytic system is constituted by all the components of the reference ternary system, even if in the physical mixture Pt and Ba are deposited on different alumina particles [44],... 

Richter, A., Langpape, M., Kolf, S. et al. (2002) Combinatorial preparation and high-throughput catalytic tests of multi-component deNO(x) catalysts. Appl. Catal. B Environ., 36, 261. 

The catalysts 8% and 5% Cu/A1203 were prepared as already reported (4) by using A1203 (BET=300 m2/g, PV=1.0 ml/g) from Grace Davison. Catalytic tests were carried out in different solvents under 1 atm of H2. 

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