A comparative study on the production yield of H atom in the thermal decomposition of i-C4H10 and n-C4H10: Examination of the contribution of the roaming radical channels

Abstract The yields of H atoms in the thermal decomposition of i-C 4 H 10  → products (1) and n-C 4 H 10  → products (2) are measured at 1470–1800 K behind reflected shock waves. A comparative method is used to evaluate the branching fractions for i-C 4 H 10  → CH 3  + i-C 3 H 7 (1a) and n-C 4 H 10  → 2C 2 H 5 (2b), where, C 3 H 6 is used as a reference. The branching fractions for (1a) and (2b) are expressed by k 1a / k 1  = (0.64 ± 0.14)(10 −3 T/K) − (0.06 ± 0.23) and, k 2b / k 2  = (0.050 ± 0.059)(10 −3 T/K) + (0.49 ± 0.10), respectively. Contributions of the roaming channels are less than 12 and 5% for i-C 4 H 10  → CH 4  + C 3 H 6 (1b) and n-C 4 H 10  → CH 4  + C 3 H 6 (2c), respectively.