Computational study of the CH4+OH->CH3+H2O reaction using ab initio and density functional theory methods

The energy reaction profile for the hydroxyl radical abstraction reaction with methane has been investigated by Hartree-Fock (HF) and gaussian-2 (G2) ab initio methods. In addition, three hybrid and three Becke's 88 exchange-based non-local density functional theory (DFT) methods were also used. Various orbital basis sets, from 3-21G to 6-311G(2d,2p), with vibrational analysis for every computed geometry, were used. The DFT computed activation barriers and the enthalpy of reaction are compared with the experimental results and highly accurate G2 ab initio methods. Appropriate DFT methods for the reliable study of the hydrogen abstraction with the hydroxyl radical were selected.