Hydrocarbons through Methane Derivatives

Methanol Synthesis. Cu-ZnO-based catalyst are well known to be highly active for the methanol synthesis, that is, for the hydrogenation of CO.610 The active site, 

In a new study of a series of binary Cu-ZnO catalysts a correlation was found between methanol synthesis activity and strain in the Cu metal phase.619 Structural defects of Cu resulting from ZnO dissolved in Cu, incomplete reduction, or epitaxial orientation to ZnO are believed to bring about strain, which modifies the Cu surface and, consequently, affects the catalytic activity. The higher amount of water formed in methanol synthesis from a C02-rich feed compared to a CO-rich feed brings about significant catalyst deactivation by inducing crystallization of both Cu and ZnO.620 

Although other experimental evidence also exists for a formate to methoxy mechanism, Baiker argues that formate intermediates are not involved in the reduction of carbon oxides to methanol on Zr02-based catalysts.8,35,624 Rather, formates are intermediates in methanation (see Section 3.2.1). 

Pd on ceria catalysts prepared by various methods were shown to exhibit varying characteristics depending on the preparation methods.625 Specifically, Pd on ceria samples prepared by the deposition-precipitation method are highly active in comparison with the catalyst prepared by the conventional impregnation method. Cationic palladium species are present in the former samples after reduction with hydrogen at 300°C, suggesting that the active species are produced by strong 

The technological improvements of methanol synthesis by comparing 25 technologies are treated in a review paper.628 

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HYDROCARBONS THROUGH METHANE DERIVATIVES 3.5.1. Hydrocarbons through Methanol... 

Higher paraffinic hydrocarbons than methane are not generally used for producing chemicals by direct reaction with chemical reagents due to their lower reactivities relative to olefins and aromatics. Nevertheless, a few derivatives can be obtained from these hydrocarbons through oxidation, nitration, and chlorination reactions. These are noted in Chapter 6. 

According to another important and promising technology, hydrocarbons are produced from methanol, which, in turn, is synthesized from synthesis gas. Called the methanol-to-gasoline process, it was practiced on a commercial scale and its practical feasibility was demonstrated. Alternative routes to eliminate the costly step of synthesis gas production may use direct methane conversion through intermediate monosubstituted methane derivatives. An economic evaluation of different methane transformation processes can be found in a 1993 review.1... 

These apparent liquid densities were derived through a study of mixtures containing methane and other heavier hydrocarbons and mixtures of ethane and other heavier hydrocarbons.2... 

A. Together with methane, the hydrocarbon adamantane (75), the parent structure of 74, has a tetrahedral skeleton. Therefore derivatives of adamantane that have four different substituents at the bridgehead positions should be chiral this has been demonstrated for 76 (see Hamill and McKervey31). It follows that in 74, Ha and Hb are enantiotopic, and indeed 74 has a plane of symmetry through C(l) and C(3). A parallel situation exists in ethanol, which has a plane of symmetry through two carbon atoms and oxygen. Although H and Hb in 74 are enantiotopic, the chemical shift difference between these protons is likely to be very small. 

C-H o-bond activation of hydrocarbons by transition metal complexes is of considerable importance in modern organometallic chemistry and catalytic chemistry by transition-metal complexes [1], because a functional group can be introduced into alkanes and aromatic compounds through C-H o-bond activation. For instance, Fujiwara and Moritani previously reported synthesis of styrene derivatives from benzene and alkene via C-H o-bond activation of benzene by palladium(ll) acetate [2]. Recently, Periana and his collaborators succeeded to activate the C-H o-bond of methane by the platinum(ll) complex in sulfuric acid to synthesize methanol [3], Both are good examples of the reaction including the C-H o-bond activation. 

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