Catalyst Amount

Pepper and Supathna (1978) studies the effect on product yields of Rh-C applications ranging in amount from 1 to 30% of the original wood in the hydrogenolysis of spruce wood meal The yield of dihydroconiferyl alcohol, (9), was found to increase while the yield of 4-n-propylguaiacol, (8), decreased When the catalyst application exceeded 10%, traces of cyclohexyl derivatives were detected The maximum total yield of (8) and (9) was obtained with a 10-20% catalyst application 

With the addition of increasing amounts of Rh-C catalyst, the total yield of monomeric products increased, while the yield of chloroform extractables simultaneously decreased This finding suggests that liberation of lignin from a lignin-carbohydrate complex is facilitated by an increase in the amount of catalyst 

P/C ratio (w/w) Benzene (%) Toluene (%) Ethylbenzene (%) Xylenes (%) Trimethylbenzenes (%) 

Both examples illustrate clearly the influence of the catalyst amount in the product selectivity. Therefore, an adequate tuning of both primary/secondary reactions is required to achieve the desired product distribution. 

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Entry Catalyst Catalyst amount Conversion (time) endo/exo ee endo (exo) (%)... 

So far the problem of active center formation in chromium oxide catalysts amounted mainly to a discussion of the oxidation number of chromium that is necessary for catalytic activity. As an active species chromium ions having practically every possible oxidation number—... 

The first ternary metal oxide catalyst of Ca0-Mn0/Ce02 was prepared by simultaneous impregnation method, while the second ternary metal oxide of Ca0/Mn0-Ce02 catalyst was prepared by combination of co-precipitation and impregnation method. The catalysts composition used in this paper were based on multi-responses optimization result [3]. H2-TPR was carried out using Micromeritics 2900 TPD/TPR equipped by TCD. A catalyst amount of... 

The effects of reaction temperature, pressure and catalyst amount on the catalytic activity were also studied with TBAC. The results are summarized in Table 2. The conversion of EC increased with the increase of reaction temperature and the amount of catalyst. The conversion of EC and the selectivity of DMC increased as the pressure increased finm 250 psig to 350 psig. But, at the pressure over 350 psig, the EC conversion decreased. Although CO2 is not required for this reaction, its presence alters the reaction profile. It is reported that high pressure of CO2 can inhibit the decomposition of EC to ethylene oxide and C02[12]. 

The effects of catalyst amount and reaction time were investigated as shown in Fig 2. While other conditions were kept constant, 2.5 wt% HPA (1 g in 40 g reaction mixture) showed fairly good activity. Further increase of the catalyst amount does not have serious effect on the activity. One hour was enough for the reaction to complete as illustrated in Fig. 2 (b). 

Fumed nitric acid (> 95%] 1, nitric acid/toluene (n/n)= 1.4, catalyst amount 3.3 g. 

MUF resin is widely used as an adhesive in wood industries, coating technology, paper industries and a main material in kitchenware production. In various applications, different resin properties are needed to suit its application. Important resin properties are for example higher resin solubility, low curing period with lower temperature and catalyst amount, good stability for longer shelf life, and lower free formaldehyde emission, as formaldehyde is very toxic, and can cause cancer [1]. One of the factors that affecting the MUF resin properties is the mole composition. The mole composition is a ratio of formaldehyde to amino compoimd... 

The difference in reactor performance is due to the difference in hydraulic diameters of the reaction channels, i.e. related to varying mass-transfer limitations. The micro channels of the p-gauze platinum catalyst amount to 70 pm, whereas the monoliths have channel/pore diameters of 500-1200 pm. 

Reduce the aeration rate until the reaction becomes oxygen-limited. This can be done interactively. Maintain this and then reduce the catalyst amount by 1/2 (reduce Vm by one-half)- Does the initial rate decrease by 1/2 Is the reaction still oxygen-limited ... 

Entry Catalysts Catalyst amount mg Specific rate I. conv%/min mg Pd Specific rate II conv%/min mg Pd... 

Entry Dienophile Diene Catalyst Amount Product Yield (%) e.e. 

P(COz) Temperature Flow rate Catalyst amount Total pressure W/F(CO) CO/H20 CO conversion... 

The catalyst amount is reduced, but the relative speeds of the electrochemical and the reformation reactions remain essentially the same. 

That diolefins play a role in benzene formation has also been shown over over a nickel-on-alumina catalyst. Product composition from 1-heptene as a function of the catalyst amount is shown in Fig. 3. This points also to diene intermediates 50). The same was found with carrier-free nickel and platinum 51). 

A similar procedure was used to degrade aqueous azo dyes solutions (Red M5B and Blue MR) by means of Fenton s reagent in a stirred closed reactor. The effect of the catalyst amount (Fe ) was evaluated for an aqueous solution containing 250 mg f of Red M5B and 500 mg f of H2O2. It can be seen from Figure 2 (adapted from Swaminathan et al. 2003) that the minimal catalyst amoimt needed, for the maximum COD abatement for the dye solution, is about 10 mg f of Fe, shown in curve (a). 

Figure 23. Heterogeneous Fenton degradation of 0. ImM B02 as a function of different catalyst amounts (Plot A C2-Ms, Plot B C2-Us/Ms ) in the presence of 4 mM H2O2 at pH 3.

The platinum content of the prepared catalyst amounts to 4.9 wt% as determined by UV/VIS spectrophotometry of a formed Sn-Pt complex (27-25). The volume-surface mean platinum diameter as determined by computer aided TEM micrograph analysis amounts to 1.85 0.04 nm. This is in good agreement with a fraction of exposed platinum atoms of 0.75 as determined from CO chemisorption, assuming a 1 1 stoichiometry (24). 

The utility of SCFs for PTC was demonstrated for several model organic reactions - the nucleophilic displacement of benzyl chloride with bromide ion (26) and cyanide ion (27), which were chosen as model reversible and irreversible Sn2 reactions. The next two reactions reported were the alkylation and cycloalkylation of phenylacetonitrile (28,29). Catalyst solubility in the SCF was very limited, yet the rate of reaction increased linearly with the amount of catalyst present. Figure 5 shows data for the cyanide displacement of benzyl bromide, and the data followed pseudo-first order, irreversible kinetics. The catalyst amounts ranged from 0.06 (solubility limit) to 10% of the limiting reactant, benzyl chloride. 

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