Sponge catalyst

T. A. Johnson and D. P. Freyberger, Lithium Hydroxide Modified Sponge Catalysts for Control of Primary Amine Selectivity in Nitrile Hydrogenations, Chemical Industries (Dekker), 82 (Catal. Org. React.), 201-227 (2000). 

Cavallito (66) reports that neither it nor 3-benzoxypyridine was hydrogenated in the presence of Willstatter s palladium sponge catalyst (67). Under low pressure conditions in ether or dioxane Raney nickel and platinum oxide were ineffective. However, other examples show that reduction takes place readily under a variety of conditions. Biel used Raney nickel at 125° and 50 atm (68), excellent yield of 6-propyl-3-hydroxypiperidine resulted from reduction of the pyridine in acetic acid with platinum oxide (69). Ruthenium in the conversion of 3-hydroxypyridine in aqueous solution gave very high yield of the corre-... 

Effects of Halogens- A study of the partial catalytic oxidation of CH4 over palladium sponge catalysts by Cullis et al. yielded some information quite relevant to its use for complete oxidation in air pollution control. They found that (1) the presence of higher alkanes or of partial oxidation products of methane, HCHO and CH3OH, retard the overall oxidation of the CH4 (2) the wide variety of halomethanes studied retarded the oxidation of CH4 to different extents and (3) some chloromethanes increased the production of HCHO with high selectivity. They attributed the latter to the modification of the elecuonic properties of the catalyst surface by the chloromethane to inhibit the further oxidation of the HCHO. 

Metal Combustible Solid nickel sponge catalyst may ignite SPONTANEOUSLY in air. 

The temperature dependence of the conversion and product formation in the ammonia oxidation over a platinum sponge catalyst is investigated. Positron emission profiling experiments demonstrate that below 413K, the catalyst deactivates due to the poisoning of the catalyst surface, mainly by... 

Ammonia oxidation is conducted on a pre-oxidised platinum sponge catalyst. Figure 20 shows the conversion and selectivity at 373 K. The same selectivity characteristics as on the reduced platinum sponge catalyst are observed (Fig. 14). Thus, a high oxygen surface coverage does not favour initial nitrous oxide formation. The main difference with the reduced platinum sponge is the faster deactivation of the pre-oxidised catalyst below 413 K. 

Fig. 20. Ammonia oxidation reaction performed at 373 K on a pre-oxidised platinum sponge catalyst (a) concentration of N2, N2O and H2O versus time for (b) conversion of NH3 and O2 versus time (GHSV = 5600 hr , NH3/O2 = 2/1.5, flow = 46.5cm /min.).

FIGURE 51.11 Normalized C-labeling responses of (A) Ne (solid line), CO (dashed line), and methanol (A) (B) methanol methanol (closed markers) and ethanol (open markers) for Co sponge catalyst. , CHsOH O, QHsOH A, CH20H , CHjOH. T = 498 K. 

A reaction yield of 99% was achieved in the capillary-microreactor, whereas the conventional method yielded only 48% of gluconic acid. In the capillary microreactor, the higher surface area of the porous sponge catalyst is responsible for a high reaction yield. 

In 1839 Kuhlmann described ammonia oxidation to produce nitrogen oxides for nitric acid production using a platinum sponge catalyst at 300 C. At the same time he was also granted a patent for the oxidation of sulfur dioxide and used the process in his factoiy at Loos. He was apparently unaware of the Phillips patent granted in the United Kingdom, but he attempted to make sulfuric acid with a platinum catalyst. 

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