A computational study on the structures and energetics of isobutanol pyrolysis

Density functional theory (BMK and BBIK) and ab initio (CBS-QB3) methods have been used to study unimolecular thermal decomposition of isobutanol (2-methylpropanol) as a fossil fuel alternative. Complex and simple decompositions have been investigated. Elimination of water molecule to form isobutene represents the most thermodynamically and kinetically preferable reaction. However, fission of the Cα–Cβ bond to give hydroxymethyl and isopropyl radicals was found to be the most favorable simple decomposition pathway. The results show a good agreement between the calculated and experimental enthalpies of formation for isobutanol and its derived radicals.