First Principle Investigations of Bulk Properties and Catalytic Reactions for Cubic Perovskite Catalyst on OCM High Temperature Process

The present work tries to show that the quantum mechanics and ab initio calculations can be used as a virtual chemistry lab for studying reactions at surfaces and is divided into three parts. In the first part, the ab initio geometry optimization of cubic BaTiO3 perovskite structure as a catalyst for oxidative coupling of methane (OCM) reaction by using hybrid DFT (B3PW, B3LYP) is described. The optimized properties and effective Mulliken charges of Ba+2, Ti+4 and O-2 for bulk BaTiO3 catalyst are compared with those available from experimental or theoretical data. Then the catalytic cycle responsible for coupling of methane over the catalyst is shown. This mechanism is more consistent with Ito-Lunsford mechanism on Li/MgO oxide catalyst proposed earlier.