Theoretical study on the reaction of methane and zinc oxide in gas phase

The mechanism of the reaction between CH4 and ZnO has been studied theoretically at the CCSD(T)//B3LYP/6-311++G(2d,2p) levels. Four possible reaction pathways, yielding three products of syngas, HCHO and CH3OH, respectively, have been evaluated. All the four pathways are predicted to occur via the formation of CH4ZnO molecular complex with two H atoms of CH4 approaching to the Zn end of ZnO. From this complex, the insertion of ZnO into the CH bond of CH4 might proceed through two concerted manners along with charge transfer process. The pathway corresponding to the production of syngas is energetically feasible, in which the cleavage of CH and ZnH bonds with the formation of H2 molecule is predicted to be the rate-limiting-step with the energy barrier of 45.4 kcal/mol.