Catalyst, effect of composition

Effect of Catalyst Composition. Where acetic is the typical acid substrate, effective ruthenium catalyst precursors include ruthenium(IV) oxide, hydrate, ruthenium(III) acetyl-acetonate, triruthenium dodecacarbonyl, as well as ruthenium hydrocarbonyls, in combination with iodide-containing promoters like HI and alkyl iodides. Highest yields of these higher MW acids are achieved with the Ru02-Mel combination,... 

Garcia, L., French, R., Czemik, S., Chornet, E., Catalytic steam reforming of bio-oils for the production of hydrogen effects of catalyst composition, Appl. 

Effect of Composition and Pretreatment on Coke and H2 Selectivity. We examined the effect of catalyst composition and pretreatment on the selectivity for coke and H2. Results (Figures 5 and 6) indicate higher yields of coke and H2 at constant conversion for SA-59 relative to catalysts with lower alumina content. Pretreatment conditions influenced coke, H2 yields indirectly by influencing surface area and gas oil conversion. Thus, coke and H2 selectivity was not influenced by pretreatment conditions. We conclude that coke and H2 selectivity does not correlate with the concentration of A1 species of a particular coordination (eg., tetrahedral). 

J. Scherzer and d.P. McArthur "Catalytic Cracking of High Nitrogen Petroleum Feedstocks Effect of Catalyst Composition and Properties", Ind. Eng. Chem. Res. 1988, 27, p 1571-1576. 

Rates of deactivation of Ni and Ni bimetallic catalysts as a result of poisoning by 10-ppm H2S during methanation were investigated in a series of studies by Bartholomew and co-workers (23, 113, 161, 194). Effects of catalyst composition and geometry, gas composition and reaction temperature on the rate of deactivation were considered. Deactivation rates were found to be relatively insensitive to temperature and quite sensitive to gas and catalyst composition (194). In fact, the rates of deactivation were 2-3 times more rapid in a H2-rich mixture (H2 /CO = 99), compared to a normal synthesis (H2/CO = 3-4) mixture. 

Effects of Catalyst Composition on Activity. Seven NiMo HTO catalysts were prepared at acidification pHs of 4. This series of catalysts (Table I) was... 

Fig. 4. Effect of catalyst composition on polymerization of olefins [96], E, ethylene P, propene TiCl3/AlR3, [Ti] = 2.6 X 10 mole 1 E 450 torr temp., 50°C P 355 mm temp, 56°C. Cg p, ml of monomer polymerized.

Fig. 5. Effect of catalyst composition on polymerization rate, (a) Isoprene, TiCl4/Al(i-Bu)3 [41 ] (b) butene-1, TiCU/AKi-Buls [98] (c) ethylene, TiCl4/LiAlR4 [97].

The effect of catalyst composition on the selectivity to the desired CDE is remarkable. It is clear that monometallic cluster catalysts almost completely hydrogenate CDT to CDA, whereas all three bimetallic clusters (RuSn, RhSn, and PtSn ) exhibit high selectivity toward CDE at approximately the same CDT conversion (50-75%). Pure tin clusters derived from Ph SnH are poor catalysts both in terms of activity and selectivity (conversion less than 10%). 

Table III. Effect of Catalyst Composition on Wax Product in Fischer Synthesis...

Table 2. Effect of catalyst composition on the catalytic performances Tc=750°C, Ti=750°C. H20/CH4=1.

J. Rasko, P. Pereira, G.A. Somoijai, and H. Heinemann. The Catalytic Low Temperature Oxydehydrogenation of Methane Temperature Dependence, Carbon Balance and Effects of Catalyst Composition. Catal. Lett. 9 395 (1991). 

Table 2. Effect of Catalyst Composition Ti(OC4H9-n)4 Plus AIR3 for the Polymerization of 1,6-Heptadiyne ...

Chart 11.2 Investigation of reaction parameters [9]. (a) Effect of catalyst composition on the reaction rate at different pressures (Pd = 4.4x 10 mol,... 

Wigle DT, Arbuckle TE, Walker M, Wade MG, Liu S, Krewski D (2007) Environmental hazards evidence for effects on child health. J Toxicol Environ Health B 10 3-39 Wilson MR, Lightbody JH, Donaldson K, Sales J, Stone V (2002) Interactions between ultrafine particles and transition metals in vivo and in vitro. Toxicol Appl Pharmacol 184 172-179 Winer AM, Behrentz E (2005) Estimates of nitrous oxide emissions from mobn vehicles and the effects of catalyst composition and aging. Final report, submitted to the State of California Air Resources Board (Contract No. 02-313), p 216... 

This reaction has been examined in great depth on a number of supported and unsupported metals in various laboratories, and extensive use of deuterium for isotopic labelling has led to very detailed mechanistic schemes. In this section we focus on the products formed with hydrogen, and the effect of catalyst composition and structure thereon studies bearing directly on detailed mechanism are deferred to the next section. 

Shih, S., E. Reiff, R. Zawadski and J.R. Katzer. "Effect of Catalyst Composition on Quinoline and Acridine Hydrodeni trogenation." ACS Div. Fuel Chem. 23(1) (March, 1978) 99. 

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