Light alkanes temperature dependences

Davis SM, Zaera F, Somorjai GA (1982) Surface structure and temperature dependence of light-alkane skeletal rearrangement reactions catalyzed over platinum single-crystal surfaces. J Am Chem Soc 104 7453... 

The behavior of alkenes in oxidation significantly differs from that of alkanes. Normal alkenes are generally easy to oxidize over Pt, Pd and Rh. Contrary to normal alkanes, their reactivity depends litde on the chain length for 7 < n < 10 while the light-off temperature of shorter alkenes (C2-C6) slightly increases with the chain... 

Kinetic modeling enabled to establish the mechanism of the nonlinear phenomena accompanying the oxidation of light alkanes. For example, simulations of the NTC for the low-temperature oxidation of propane showed that the leading species in this phenomenon are the propylperoxy radical and its isomers [165]. The simulation results obtained in [168] almost quantitatively (within 10 K) agreed with the experimentally determined temperature boundaries of the NTC region and closely reproduced the form of the temperature dependence of the induction period. An explanation of this phenomenon is based on the widely held view that contribution from the removal of HO2, a low-active radical, from the propylperoxy radical. 

PCAs are produced by chlorination of CJ0-C30 n-alkanes using molecular chlorine, either of the liquid paraffin or in a solvent, typically carbon tetrachloride [5,10]. For specialized and more limited applications, PCAs have also been produced by addition chlorination of a-olefins [11]. Depending upon the n-alkane feedstock, the reaction takes place at temperatures between 50 and 150°C, at elevated pressures and/or in the presence of UV light [1,4]. After chlorination the product is stripped of solvent, residual chlorine, and reaction products (e. g., HC1) by gas sparging. Final products are mixtures that are viscous, colorless or yellowish dense oils, except for C20-C30 PCAs of high chlorine content (70%) which are solids [5]. 

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