Catalyst drying

Method 1. From ammonium chloroplatinate. Place 3 0 g. of ammonium chloroplatinate and 30 g. of A.R. sodium nitrate (1) in Pyrex beaker or porcelain casserole and heat gently at first until the rapid evolution of gas slackens, and then more strongly until a temperature of about 300° is reached. This operation occupies about 15 minutes, and there is no spattering. Maintain the fluid mass at 500-530° for 30 minutes, and allow the mixture to cool. Treat the sohd mass with 50 ml. of water. The brown precipitate of platinum oxide (PtOj.HjO) settles to the bottom. Wash it once or twice by decantation, filter througha hardened filter paper on a Gooch crucible, and wash on the filter until practically free from nitrates. Stop the washing process immediately the precipitate tends to become colloidal (2) traces of sodium nitrate do not affect the efficiency of the catalyst. Dry the oxide in a desiccator, and weigh out portions of the dried material as required. 

Specimens were placed in a silica reactor that was equipped with two side tubes for XPS and ESR measurements and connected to a circulation apparatus, described elsewhere [25, 26]. The catalysts, dried at 383 K, were characterized as prepared (a.p.), after heating in dry oxygen at 773 K (s.o.), or after reduction with CO. In some experiments, as specified, samples were exposed to NO, NH3, or various mixtures NO-O2-NH3. Electrons per V atom (e/V) were determined from the CO consumed. The average oxidation number of vanadium was calculated as 5 - eA/. 

Table 1 Selective oxidation of geraniol using air as oxidant. Conditions 0.085mol geraniol in toluene, 5wt.% loading of catalyst (dry weight), 60°C, 3bar air, 600rpm, 6h.

On bimetallic Ag3.7Co2.6AF catalyst dry SCR activity dramatically decreased (Fig.2a). 

Chlorobenzene is produced by the electrophilic chlorination of benzene in the liquid phase96,97 catalyzed by FeCl3 at 25-50°C. As a result of corrosion problems and deactivation of the catalyst, dry reactants must be used. A few percent of dichlorobenzene is formed as byproduct. 

In this process, carbon from biomass is converted to gases (CO, CO2) by high temperature (above 800 °C). The produced CO2 can react with hydrogen to directly produce methane, but also other different products, such as diesel, and other chemicals such as 1-alkenes in the presence of catalysts (Dry, 1999). This process has been used to produce Fischer-Tropsch diesel (FT diesel). 

Many studies address the effect of promoters such as K and Mn on Fe-based catalysts. Dry et al (23) suggest that the alkali promoter weakens the C-O bond and enhances its rate of dissociation it also strengthens the metal-C bond, the surface residence time of adsorbed chains, and the probability of chain growth. In the presence of Mn, termination to olefins predominates (24-26). Our results suggest that we must also consider the effect of promoters and of catalyst treatment on a-olefin readsorption. Perhaps the presence of alkali also enhances a-olefin readsorption reactions leading to heavier products whereas Mn does not. 

C, 6 h TBAB as phase-transfer catalyst Dry CHC13, reflux, 16 h, T 2,2 -bipyridine, column chromatography for separation from the dimeric product... 

Fig. 15. 1% (see Fig. 14) can be replaced by just 1% air, to achieve the complete elimination of anode poisoning at 20 ppm CO, when a prefilter with Pt/C catalyst (dry, unimpregnated gas-diffusion electrode) is placed upstream of the anode. The anode catalyst was a thin-film containing 0.14 mg Pt/cm [21]. (Reprinted by permission of the American Chemical Society). 

Use Bleaching agent for flour, fats, oils, and waxes polymerization catalyst drying agent for unsaturated oils pharmaceutical and cosmetic purposes rubber vulcanization without sulfur burnout agent for acetate yams production of cheese embossing vinyl flooring (proprietary). 

FIGURE 50 Pore volume distribution of Cr/silica-titania catalysts dried by various methods and then activated at 800 °C. The mesoporosity of the catalyst influences its activity and the polymer melt index (tested at 105 °C with 1.5 mol C2H4 L ). 

FIGURE 51 Dependence of the catalyst activity and of the polymer MW and Ml on the mesoporosity (shown here as the volume inside pores of 100-1000 A diameter) in a series of catalysts dried by replacing the pore water with various organic solvents. 

TABLE 22 Pore Volumes of Catalysts Dried by Various Methods. A Low pH in Silica Hydrogel Decreased Shrinkage During the Drying Step... 

Recent examples, for instance, of the catalytic application of the commercially available macroporous Amberlyst-15 include the Michael addition of pyrroles to a,P-unsaturated ketones (Scheme 10.4) [48]. In this process, the acid ion exchange resin (dry, 10% w/w) allows on to obtain mono and dialkylated pyrroles 5 and 6 in reasonable yields. Similarly, this catalyst (dry, 30% w/w) can catalyze the aza-Michael reaction of amines with a,P-unsaturated ketones, esters and nitriles to afford 7 in 75-95% yields under solvent-free conditions. Interestingly, yields were significantly lower using typical solvents such as DCM (dichloromethane), CH3CN, THF, DMF or EtOH [49], Recycling the catalyst is possible in both cases, but a smooth decrease in the yield is observed for each new run. 

A catalyst was prepared by impregnating a sample of alumina with a solution of sodium tungstate and mixing with the aid of ultrasonic agitation. The sample was dried in a vacuum dessicator ( 4 hour) and in air at 90°C (1 hour). Concentrated nitric acid (10 mL) was added and the beaker warmed on a hot plate for 5 minutes and the solid was then washed with 1M nitric acid by decantation. To remove sodium nitrate, 1M nitric acid (250 mL) was added, the catalyst digested for 1 hour on a hot plate and the nitric acid decanted. This washing was repeated three times and the catalyst dried at 150-160°C. 

Initial Rate of Reaction as a Function of Catalyst Drying Temperature... 

TABLE 1 CHEMICAL ANALYSIS DATA (% wt/wt) OF THE SPENT COMMERCIAL NiMo/Al203 CATALYST (dry basis)... 

Cobalt catalyst Metal catalyst Metal catalyst, dry, 4.2 Metal catalyst, wetted with a visible excess of liquid, 4.2 Metal catalyst, wetted without a visible excess of liquid Nickel catalyst... 

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