Addition of n-C4H10 and C4H8 to slowly reacting mixtures of hydrogen and oxygen at 480°C. Part 1.—Formation of hydrocarbon products

Abstract

When small amounts of n-C4H10 are added to slowly reacting mixtures of H2+ O2+ N2 at 480°C, the main products are the conjugate olefins. The variation of the yields of C2H4 and of C3H6 with O2 concentration indicates that they are formed by decomposition of n-C4H9 and s-C4H9 radicals, respectively. The products formed on addition of the conjugate olefins have also been examined. The results show that the excited C4H9 radicals formed by H-addition, particularly with but-1-ene, decompose much more rapidly than C4H9 radicals formed by H-abstraction from n-C4H10; the significant yield of butadiene from the butenes indicates the importance of H-abstraction from the weak α-C–H bonds. Velocity constants at 480°C for n-C4H9+ O2 giving but-1-ene, and s-C4H9+ O2 giving but-1-ene, cis-but-2-ene and trans-but-2-ene are 2.7 × 108, 5.1 × 107, 4.3 × 107 and 7.8 × 107 dm3 mol–1 s–1, respectively.