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.