Carbon Monoxide and Propene

The irradiation of 2,5-dimethylfuran in the presence of mercury vapor gave a complex mixture of products. Carbon monoxide and propene were removed as gaseous products. Then, cis- and rran.s-l,3-pentadiene, isoprene, 1,3-dimethylcyclopropene, 2-pentyne, 2-ethyl-5-methylfuran, hexa-3,4-dien-2-one, 1-methyl-3-acetylcyclopropene, and 4-methylcyclopent-2-enone were obtained (Scheme 8) (68JA2720 70JA1824). The most abundantproduct was the cyclopentenone 19, the second was the 1,3-pentadiene 12, while the third product was the cyclopropenyl derivative 18. 

J. S. Walker, G. I. Straguzzi, H. Manogue, and G. C. A. Schuit,Carbon monoxide and propene oxidation by iron oxides for auto-emission control, J. Catal.lKHl), 298-309 (1988). 

The synthesis of isotactic copolymers from carbon monoxide and propene has been more difficult to achieve. The stereoselective copolymerization of carbon monoxide and propene has been most selective with catalysts containing alkyl-substituted bisphosphines. The catalyst containing the dialkylphosphino biaryl ligand in Figure 17.16 has been shown... 

Biaryl bisphosphine reported by Consiglio and cataiyst reported by Sen for the copolymerization of carbon monoxide and propene to form syndiotactic CO/propylene copolymer. 

The final difference in the copolymerization of carbon monoxide with propene or styrene is the overall connectivity of the initial polymer generated under some conditions. The polymer generated from the copolymerization of carbon monoxide and propene in protic solvents consists of the fused tetrahydrofuran ketal structure shown in Figure 17.17. This polymer reopens to the polymer shown in Figure 17.13 upon addition of acid in alcohol. Several mechanisms for formation of this product have been proposed, and the origin of the ketal structure remains unresolved. Polymers formed in aprotic solvents form the acylic polymer. 

Gambs, C. Chaloupka, S. Consigho, G Togni, A. Ligand electronic effect in enantioselective palladium-catalyzed copolymerization of carbon monoxide and propene. Angew. Chem., Int. Ed. 2000, 39, 2486-2488. 

Acidic or basic promoters can affect the activity of Pt and Pd supported on alumina or zirconia. Basic promoters (e.g. Na) improve CO and propene oxidation while they inhibit NO oxidation. By contrast, acidic promoters (e.g. sulfates) show the greatest effect in propane oxidahon. Carbon monoxide and propene are too shongly adsorbed (with respect to O2) the effect of basic promoters would be to weaken their adsorphon on the metals and thereby to reinforce that of oxygen. The reverse is true for acidic promoters they strengthen the adsorption of propane, too weakly adsorbed on Pt and Pd (see Section 1.2.5). The same result can be observed if sulfates are replaced by SO2 directly injected with the propane/air mixture. The... 

The adsorption of oxygen, carbon monoxide, and propene on C112O and the adsorption of carbon monoxide on CuO have been reported. 

The parent NH4ZSM-5 (Zeolyst, Si A 1=15) was treated with a 0.1 M Co(N03)2 at room temperature. The ion exchange procedure was repeated three times and then the precipitate was washed with water and dried at 380 K. The cobalt content corresponded to Co/Al = 0.18. We used also MgZSM-5 (Mg/Al = 0.10) obtained by the treatment of NH4ZSM-5 with Mg(N03)2 solution. Propene (MERCK 99 %), as well as carbon monoxide, and nitrogen monoxide (Linde Gas Polska 99.95%, and 99.5% resp.) were used as adsorbates. 

It was recognized during the development of propene hydroformylation that propene provided some stabilization for the catalyst. In the absence of the alkene, but in the presence of carbon monoxide and hydrogen, the catalyst can undergo what has been termed intrinsic deactivation. [3 3] Apparently after oxidative addition of triphenyl-phosphine to rhodium, diphenylphosphido bridged rhodium complexes are formed. 

This type of process represents the ideal biphasic method as long as the product can be extracted without contamination from the catalyst and catalyst immobilization solvent. This technique is employed commercially for the production of butyraldehyde from propene, carbon monoxide and hydrogen which is described in detail in Chapter 11 [3],... 

Ray and Chanda [261] studied bismuth molybdates (prepared by the method of Peacock [250,251]) in an integral flow reactor. At constant W/F = 8 g h mol-1 and a feed ratio isobutene/oxygen = 1/6, a maximum selectivity of 75% was found at 400—450°C. As with propene, the reaction is first order with respect to isobutene and the rate is independent of the oxygen pressure. The reoxidation of the catalyst is very fast. Assuming that the kinetics can be described by three parallel first-order reactions for the production of methacrolein, carbon monoxide and carbon dioxide, rate coefficients were calculated (Table 18). 

Studies with gold catalysts have focused on the selective reduction of nitric oxide by propene, carbon monoxide and hydrogen urea,10 methane11 and other hydrocarbons9,11,13 have also been used. NOx removal using the first three of these will now be discussed. 

Complete oxidation of propene by Pt/A Os in the presence of carbon monoxide is made easier by admixture with Au/TiC>2, which oxidises the carbon monoxide and prevents its toxic effect on the platinum.77... 

Example 5.2. Hydroformylation of propene [2]. Hydroformylation converts an olefin to an aldehyde of next higher carbon number by addition of carbon monoxide and hydrogen. The reaction is catalyzed by dissolved hydrocarbonyl complexes of transition-metal ions such as cobalt, rhodium, or rhenium. The carbon atom of the carbon monoxide can attach itself to the carbon atom on either side of the olefinic double bond, so that two aldehyde isomers are formed. If the catalyst also has hydrogenation activity, the aldehydes are converted to alcohols and paraffin is formed as by-product. For propene and such a catalyst the (simplified) network is ... 

Raising the temperature increases the amount of gas. At temperatures beyond 550°C, the gas fraction increases rapidly, reaching 42 wt% at 590°C. The gas consists of methane, ethene, propene, carbon monoxide and carbon dioxide (Table 24.2). 

At the same time there is an increase of carbon dioxide, carbon monoxide, methane, propene, and other gaseous components. The low-boiling components are carbon oxides and hydrocarbon while the higher-boiling components are esters. Mechanistically, the pyrolytic conversion of PMMA to its monomer is a radical process [24]. Two radicals are formed by the action of heat of the polymer chain (Scheme 24.1). 

Chain decomposition of formaldehyde would be fast, and give carbon monoxide and hydrogen as products. Although absence of any appreciable inhibition by isobutene and propene was reported, this does not exclude free radical chains since formic acid and formaldehyde are both excellent free radical scavengers, (i.e., i)(H-COOH) = 88 kcal.mole Z)(0=CH-H) = 85 kcal.mole ). Chains can also be propagated readily by allylic radicals at the reaction temperatures (709-805 °K). 

The highest propene oxide yields were obtained with both the Ti-SBA-15- and the Ti-silica-supported catalysts, although a higher reaction temperature was needed in comparison to the titania-supported catalyst. The deactivation for these catalysts was also considerably less. At lower temperatures (up to 423 K), all catalysts had an inhibition period for both propene oxide and water formation, which is explained by product adsorption on the support. The side products produced by all catalysts were similar. Primarily, carbon dioxide and acetaldehyde were produced as side products and, in smaller quantities, also propanal, acrolein, acetic acid, and formaldehyde. Propanol (both 1- and 2- as well as propanediol), acetone, carbon monoxide, and methanol were only observed in trace amounts. 

The series of nickel molybdates tested for oxidative dehydrogenation of propane produced a product spectrum limited to propene, carbon dioxide, carbon monoxide, and water. No cracking... 

We studied the influence of M0O3 on the catalytic properties of aNiMo04. The catalytic test was carried out 375°C with 0acetic acid (acet ), acrylic acid (aery), carbon monoxide and carbon dioxide. Table 4 shows that the activity and the selectivity of the mixed systems [aMo03 aNiMo04 ] differ very much from these of aNiMo04 and aMo03 phases. 

When the electric current was 1.1 mA, i.e., 10.2 pmolThr of oxygen flux, the formation rates of acrylaldehyde, carbon monoxide and carbon dioxide were 0.33, 1.9 and 4.53 (xmol/hr, respectively, and the oxygen consumption rate of 9.02 pmol/hr was calculated by assuming water as another oxidation product. Mass balance calculated between oxygen evolution and consumption of propene oxidation was about 90%. 

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