Nickel catalyst Nitric oxide

Dioxane may react violently with Raney nickel catalyst, nitric and perchloric acids, sulfur trioxide, and strong oxidizing reagents. 

Dodecanedioic Acid. Dodecanedioic acid (DDDA) is produced commercially by Du Pont ia Victoria, Texas, and by Chemische Werke Hbls ia Germany. The starting material is butadiene which is converted to cyclododecatriene usiag a nickel catalyst. Hydrogenation of the triene gives cyclododecane, which is air oxidized to give cyclododecanone and cyclododecanol. Oxidation of this mixture with nitric acid gives dodecanedioic acid (71). 

Other metal oxide catalysts studied for the SCR-NH3 reaction include iron, copper, chromium and manganese oxides supported on various oxides, introduced into zeolite cavities or added to pillared-type clays. Copper catalysts and copper-nickel catalysts, in particular, show some advantages when NO—N02 mixtures are present in the feed and S02 is absent [31b], such as in the case of nitric acid plant tail emissions. The mechanism of NO reduction over copper- and manganese-based catalysts is different from that over vanadia—titania based catalysts. Scheme 1.1 reports the proposed mechanism of SCR-NH3 over Cu-alumina catalysts [31b],... 

A small amount of adipic acid, 2%, is made by hydrogenation of phenol with a palladium or nickel catalyst (150°C, 50 psi) to the mixed oil, then nitric acid oxidation to adipic acid. If palladium is used, more cyclohexanone is formed. Although the phenol route for making adipic acid is not economically advantageous because phenol is more expensive than benzene, the phenol conversion to greater cyclohexanone percentages can be used successfully for caprolactam manufacture (see next section), where cyclohexanone is necessary. 

Adipic acid can also be made by hydrogenation of phenol with a palladium or nickel catalyst (150°C, 50 psi) to the mixed oil, then nitric acid oxidation to adipic acid. If palladium is used, more cyclohexanone is formed. 

Nickel as a Catalyst.—A mixture of nitric oxide and hydrogen passed over reduced nickel yields ammonia. The reaction, which is nearly quantitative, begins at 300° C., but when once it has set in the temperature may be lowered to 120° C. Nitric oxide alone, however, on being passed over reduced nickel does not yield any nitride, nitrite, or nitrate.10 When sulphur dioxide and hydrogen are passed over nickel at dull red heat, hydrogen sulphide is formed, and hydrogen phosphide results when hydrogen is passed over a mixture of reduced nickel and... 

In the first step, phenol is hydrogenated in the molten state to cyclohexanol, in the presence of a nickel catalyst The operation takes place at around 150°C and 03 -106 Pa absolute. Once-through conversion of phenol is up to 99.5 per cent The second step consists in oxidizing the cyclohexanol to adipic acid by nitric add, in the presence of a... 

Platinum is an effective oxidation catalyst for carbon monoxide and the complete oxidation of hydrocarbons. Palladium also promotes the oxidation of carbon monoxide and hydrocarbons but is more sensitive to poisoning than platinum in the exhaust environment. Both platinum and palladium promote the reduction of nitric oxide but are less effective than rhodium. In addition to the noble metals, three-way catalysts contain the base metal cerium and possibly other additives such as lanthanum, nickel or iron. These base metal additives are believed to improve catalyst performance by extending conversion during the rapid air-fuel ratio perturbations and help to stabilize the alumina support against thermal degradation. 

METHYL HYDRATE (67-56-1) CH O CH3OH Flammable liquid. Forms explosive mixture with air [explosion limits in air (vol %) 6.0 to 36.5 flash point 52 F/11 C autoignition temp 725°F/385°C 867°F/464°C " Fire Rating 3]. Violent reaction (possible fire and/or explosion) with strong oxidizers strong mineral acids (e.g., nitric, sulfuric, perchloric) acetyl bromide alkyl aluminum salts beryllium dihydride bromine, chromic acid l-chloro-3,3-difluoro-2-methoxycyclopropene, cyanuric chloride diethylzinc, isophthaloyl chloride potassium-ferf-butoxide phosphorus trioxide platinum-black catalyst (ignition) potassium sulfur diimide Raney-nickel catalysts 2,4,6-trichlorotriazine, triethylaluminum, 1,3,3 -trifluor o-2 -... 

Ammonia selectivity of platinum and platinum-nickel catalysts for NOx reduction varies with the nature of the supporting oxide. Silica, alumina, and silica-alumina supports on monolithic substrates were studied using synthetic automotive exhaust mixtures at 427°-593°C. The findings are explained by a mechanism whereby the reaction of nitric oxide with adsorbed ammonia is in competition with ammonia desorption. The ease of this desorption is affected by the chemistry of the support. Ammonia decomposition is not an important reaction on these catalysts when water vapor is present. 

We explored the mechanistic implications of the apparent importance of acidity to ammonia selectivity, beginning with the assumption that ammonia is an intermediate in the reduction of nitric oxide over precious metal catalysts. (Attempts to explain our observations on the alternative assumption that chemisorbed isocyanate is the active intermediate (7) were fruitless since nickel should not change isocyanate s behavior. However, an acidic surface would probably lower isocyanate stability.) Since the total conversion of NO increased with nickel addition, it is likely that some conversion takes place on the nickel, probably by the reaction of NO with hydrogen spilled over from the platinum. Disappearance of this ammonia could occur by ammonia decomposition (Reaction 1) as hy-... 

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