Gas-Phase Reaction between Hydrocarbons and Metal Oxides: The AlO + CH4 Reaction from 590 to 1380 K

Article abstract of DOI:10.1021/j100116a002

A recent ab initio study suggested that gaseous metal oxides can directly abstract H atoms from hydrocarbons, but with considerable barriers.To try to confirm the occurrence of such reactions, the title reaction has been studied in a high-temperature fast-flow reactor.The data are well described by a fitting expression k(590-1380 K) = 9.6 * 10^-39(T/K)^7.96 exp(2468 K/T) cm³ molecule^-1 s^-1, with 2? precision limits varying with temperature from +/- 4percent to +/- 12percent.The corresponding 2? accuracy limits are about +/- 25percent.Comparison of this result to further ab initio and conventional transition-state theory calculations suggests that direct abstraction indeed can occur at the higher temperatures but that one or more other channels, possibly involving AlO insertion into a C-H bond, dominate in the initial attack step.The potential implications of this work for catalytic conversion of methane to higher hydrocarbons are considered.