Carbon monoxide reaction with hydrocarbons

Potential Processes. Sulfur vapor reacts with other hydrocarbon gases, such as acetjiene [74-86-2] (94) or ethylene [74-85-1] (95), to form carbon disulfide. Higher hydrocarbons can produce mercaptan, sulfide, and thiophene intermediates along with carbon disulfide, and the quantity of intermediates increases if insufficient sulfur is added (96). Light gas oil was reported to be successflil on a semiworks scale (97). In the reaction with hydrocarbons or carbon, pyrites can be the sulfur source. With methane and iron pyrite the reaction products are carbon disulfide, hydrogen sulfide, and iron or iron sulfide. Pyrite can be reduced with carbon monoxide to produce carbon disulfide. 

Aromatic Aldehydes. Carbon monoxide reacts with aromatic hydrocarbons or aryl haHdes to yield aromatic aldehydes (see Aldehydes). The reaction of equation 24 proceeds with yields of 89% when carried out at 273 K and 0.4 MPa (4 atm) using a boron trifluoride—hydrogen fluoride catalyst (72), whereas conversion of aryl haHdes to aldehydes in 84% yield by reaction with CO + H2 requires conditions of 423 K and 7 MPa (70 atm) with a homogeneous palladium catalyst (73) and also produces HCl. 

Perhaps the most familiar example of heterogeneous catalysis is the series of reactions that occur in the catalytic converter of an automobile (Figure 11.12). Typically this device contains 1 to 3 g of platinum metal mixed with rhodium. The platinum catalyzes the oxidation of carbon monoxide and unburned hydrocarbons such as benzene, C6H6 ... 

In the current volume a variety of subjects is treated by competent authors. These subjects deal with new techniques of surface investigations with the microbalance, with the elucidation of reaction mechanisms by the concept of intermediates, and with specialized studies of the ammonia synthesis, hydrogenations, carbon monoxide oxidation and hydrocarbon syntheses. In addition, Volume V contains an extensive critical review of Russian literature in catalysis. 

Carbon monoxide reacts with [Fe(TPP)] to form a five-coordinate complex [Fe(TPP)CO], which can be reduced electrochemically to the corresponding iron(I) species from which, however,245 CO spontaneously dissociates. The Fe—CO interaction is stabilized by the,presence of hydrocarbon chains bound by amide linkages to the ortho position of the TPP phenyl rings. Carbon monoxide adducts of iron(I) complexes of a number of these superstructured porphyrins have been reported.245 The chemistry of these highly reduced species is of relevance to understanding240 the reactions of cytochrome P-450 and the peroxidases. 

Species profiles have not been measured directly for dry CO/air or CO/O2 flames in the same way as they have for hydrogen flames. Several investigations, however, have been concerned with the oxidation of carbon monoxide in lean hydrocarbon flames (e.g. refs. 406, 413, 417, 429) or in moist CO flames flames of H2 /CO mixtures in air [167, 406, 414, 418] or O2 [523]. The interest in the oxidation in hydrocarbon flames has arisen since the overall reaction in such flames is a two stage process. In the first rapid stage (the main flame reaction zone) the hydrocarbon is essentially converted to CO and water, with traces of hydrogen also appearing. The second, more extended, stage is devoted to radical recombination and to the slower oxidation of CO, predominantly by reaction (xxiii). 

The Reppe hydrocarboxylation of acetylenes was initially carried out in the presence of an acid, but little was known about the function of the acid or the nature of the carbon monoxide transfer agent. Sternberg et al. found that diphenylacetylene can be hydrocarboxylated in alkaline solution and that in this case a nickel carbonyl anion is the source of carbon monoxide. When the hydrocarbon was shaken with a saturated solution of sodium hydroxide in methanol in the presence of excess nickel carbonyl under helium the reaction mixture turned dark red. After 80 hrs., acidification and workup aiforded a-phenyl-rru/is-cinnamic acid and 1,2,3,4-tetraphenyl-butadiene in the yields indicated. Note that the ciimamic acid results from cis addition of the elements of formic acid. 

The most striking effect of lead tetraethyl in the reaction with n-octane is on the reaction producing carbon monoxide, reaction 2. Although oxidation starts at about the same temperature as without the antiknock, the consumption of oxygen rises with increases of temperature more slowly than can be accounted for by the suppression of carbon monoxide formation particularly at low and intermediate temperatures. This indicates that the primary oxidation of the hydrocarbon (reaction 1) to aldehyde is retarded and that complete oxidation requires a higher temperature than when lead tetraethyl is absent. The disturbance which normally occurred in the reaction zone at a low temperature, takes place at a more elevated temperature when lead tetraethyl is present. 

In a partial oxidation process, methane and other hydrocarbons in natural gas are combined with a limited amount of oxygen (typically, from air) that is not enough to completely oxidize the hydrocarbons to carbon dioxide and water. With less than the stoichiometric amount of oxygen available for the reaction, the reaction products contain primarily hydrogen and carbon monoxide (and nitrogen, if the reaction is carried out with air rather than pure oxygen) and a relatively small amount of carbon dioxide and other compounds. Subsequently, in the WGS reaction, the carbon monoxide reacts with water to form carbon dioxide and more hydrogen. 

Major limitation associated with carbon dioxide reduction is the accuracy of the analytical measurements employed. The photocatalytic process is a multielectron transfer process, hence the reaction leads to the formation of a variety of products like carbon monoxide, methane, higher hydrocarbons, alcohol, aldehydes, carboxylic acid etc., with some intermediates. The identification and quantification of the products are needed for the best selection of photocatalyst, comparison and elucidation of reaction mechanisms. Currently there is no standard analysis method that has been developed for product analysis of carbon dioxide reduction. Hence the results of these measurements also include the products derived from the carbon contamination invariably present in the reaction sys-... 

Surface-science studies succeeded to identify many of the molecular ingredients of surface catalyzed reactions. Each catalyst system that is responsible for carrying out important chemical reactions with high turnover rate (activity) and selectivity has unique structural features and composition. In order to demonstrate how these systems operate, we shall review what is known about (a) ammonia synthesis catalyzed by iron, (b) the selective hydrogenation of carbon monoxide to various hydrocarbons, and (c) platinum-catalyzed conversion of hydrocarbons to various selected products. 

Other procedures for the synthesis of CNTs use a gas phase for introducing the catalyst, in which both the catalyst and the hydrocarbon gas are fed into a furnace, followed by a catalytic reaction in the gas phase. The method is suitable for large-scale synthesis, because nanotubes are free from catalytic supports and the reaction can be operated continuously. A high-pressure carbon monoxide reaction method, in which the CO gas reacts with iron pentacarbonyl to form SWNTs, has been developed [38]. SWNTs have been synthesized from a mixture of benzene and ferrocene in a hydrogen gas flow [55]. In both methods, catalyst nanoparticles are formed through thermal decomposition of organometallic compounds, such as iron pentacarbonyl and ferrocene. 

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