Oligomerization/dehydrogenation reaction

New insights may be gained by saying the above in a different way. Consider the sequential oligomerization/dehydrogenation reactions in equations 9a and 9b46 ... 

These reactions are both endothermic by a nearly constant 5 kJmol"1, (5.0 1.3) and (5.3 2.8), respectively. By contrast, the sequential oligomerization/dehydrogenation reactions of saturated alkanes (equations 10a and 10b)... 

Earlier in this chapter we talked about the enthalpies of formation of singly and then multiply substituted cyclopropanes and the correspondingly substituted benzenes. It is now time to talk about multiple cyclopropanes and the corresponding benzene derivatives. In Section II.D, the enthalpies of formation of the isomeric (cis)- and (trans)-1,1 2, 1 "-ter-cyclopropyl (9a and 9b) were estimated to be 208 kJ mol 1. It was also asserted that the difference of this value and the enthalpy of formation of bicyclopropyl (8) was nearly identical to the difference of the enthalpies of formation of bicyclopropyl and cyclopropane. Let us now rewrite the oligomerization/dehydrogenation reactions 11a and lib as reactions 31aand31b ... 

The thermochemistry of acetylenes is surprisingly sparse. Yet it is rich enough to allow some interesting comparisons. Paralleling the oligomerization/dehydrogenation reaction of olefins and alkanes (equations 9 and 10), we now suggest equation 16 ... 

These categories are specific to the different functions and chemical reactions. For example, the metals are used for dehydrogenation reactions, hydrogenation, and hydrogenolysis the solid acid-base is employed for oligomerization reactions, cyclization, cracking, and isomerization finally, the selective oxidation is mainly employed oxides. 

Another recent patent (22) and related patent application (31) cover incorporation and use of many active metals into Si-TUD-1. Some active materials were incorporated simultaneously (e.g., NiW, NiMo, and Ga/Zn/Sn). The various catalysts have been used for many organic reactions [TUD-1 variants are shown in brackets] Alkylation of naphthalene with 1-hexadecene [Al-Si] Friedel-Crafts benzylation of benzene [Fe-Si, Ga-Si, Sn-Si and Ti-Si, see apphcation 2 above] oligomerization of 1-decene [Al-Si] selective oxidation of ethylbenzene to acetophenone [Cr-Si, Mo-Si] and selective oxidation of cyclohexanol to cyclohexanone [Mo-Si], A dehydrogenation process (32) has been described using an immobilized pincer catalyst on a TUD-1 substrate. Previously these catalysts were homogeneous, which often caused problems in separation and recycle. Several other reactions were described, including acylation, hydrogenation, and ammoxidation. 

A general reaction sequence for coke formation from paraffins involves oligomerization, cyclization, and dehydrogenation of small molecules at active sites within zeolite pores ... 

Improved selectivity in the liquid-phase oligomerization of i-butene by extraction of a primary product (i-octene C8) in a zeolite membrane reactor (acid resin catalyst bed located on the membrane tube side) with respect to a conventional fixed-bed reactor has been reported [35]. The MFI (silicalite) membrane selectively removes the C8 product from the reaction environment, thus reducing the formation of other unwanted byproducts. Another interesting example is the isobutane (iC4) dehydrogenation carried out in an extractor-type zeolite CMR (including a Pt-based fixed-bed catalyst) in which the removal of the hydrogen allows the equilibrium limitations to be overcome [36],... 

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