Activity hydrocarbon

The Institut Fran ais du Petrole has developed and commercialized a process, named Dimersol X, based on a homogeneous catalyst, which selectively produces dimers from butenes. The low-branching octenes produced are good starting materials for isononanol production. This process is catalyzed by a system based on a nickel(II) salt, soluble in a paraffinic hydrocarbon, activated with an alkylalumini-um chloride derivative directly inside the dimerization reactor. The reaction is sec-... 

As a further illustration of the compensation effect, we use solid-acid-catalyzed hydrocarbon activation by microporous zeolites. A classical issue in zeolite catalysis is the relationship between overall rate of a catalytic reaction and the match of shape and size between adsorbate and zeolite micropore. 

Hydrocarbon activation and oxidation on transition metal mixed oxides ... 

J. A. Davies, P. L. Watson, J. F. liebman, A. Greenberg, Selective Hydrocarbon Activation, VCH-Wiley, Weinheim, 1990. 

Since Chatt and Davidson13 observed the first clear example of simple oxidative addition of a C—H bond of naphthalene to a ruthenium metal center, Ru(dmpe)2 (dmpe = Me2PCH2CH2PMe2), hydrocarbon activation has been the subject of many transition metal studies.11 c Sometimes, the efforts in this field have ended in findings different from the initial objectives, which have been the starting point for the development of novel organometallic chemistry. 

A collection of such methods has been given J. A. Davies, R. J. Staples, Electrochemical Approaches to Transition Metal Mediated C-H Bond Activation, in Selective Hydrocarbon Activation (J. A. Davies, P. L. Watson, J. F. Liebman, A. Greenberg, Edits.), p. 379 ff, VCH Publishers, New York 1990. 

In addition to the ability to react nonspecifically with hydrocarbons, active nitrogen can readily participate in energy transfer reactions with volatile organometal-lic compounds, leading to atomic emission from the metal atom. By use of appropriate optical filters, selective detection of elements such as aluminum, lead, tin, and mercury has been achieved in the presence of large excesses of organics [58],... 

For intermolecular hydrocarbon activation, we are not aware of any example where compelling evidence exists for C-H activation directly by square-planar four-coordinate Pt(II), without preceding (or concomitant) ligand loss. In one example, such a direct reaction may take place but the alternative explanation involving ligand loss is also consistent with the data. The compound (dmpe)PtMe(02CCF3) (dmpe = bis(dimethylphosphino)ethane) activates benzene C-H bonds at elevated temperature (125 °C) (23). This reactivity contrasts with that of (dmpe)PtMeCl which is inactive at the same temperature or even at... 

A great deal of research in the area of oxidative coupling of methane (OCM) is currently in evidence.5-10 Most investigations have been performed using oxide catalysts. Because of the proven catalytic activity of carbides in hydrocarbon activation and oxidation reaction, it was natural to try carbides in OCM. One of the key steps in this reaction is the activation of the methane molecule to form adsorbed or gaseous radical species CH3. 

The effect of lead on hydrocarbon oxidation over noble metal catalysts has been variously presented as a relation between catalyst activity and lead content in gasoline (19, 22), or of lead supplied to the engine (31, 32), etc. The most meaningful correlation is between hydrocarbon activity and lead deposit on the catalyst. Two examples of such correlations, one for laboratory-tested samples and the other for fleet-tested catalysts, will follow. 

Fig. 16. Hydrocarbon activity as a function of lead concentration on catalyst, lead concentration in fuel 0.003-0.05 g/gal. [From Otto et at. (30).] (Reprinted with permission of the Air Pollution Control Association.)...

Indeed, in the work of Fitzgerald and Wilson (55), the introduction of tributyl phosphate into the oil gave a rather steep deterioration of hydrocarbon activity. A similar sharp deterioration was also noted when an unidentified ashless antioxidant additive by itself was employed. The conclusion reached by the authors is that the presence of phosphatebinding metals, mainly Zn and Ca, is responsible for the inhibition of the poisoning influence of phosphorus from engine oils. 

Wattenberg, L.W. Dietary modification of intestinal and pulmonary aryl hydrocarbon activity. Toxicol Appl Pharmacol,... 

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