(585f) Theoretical Study of Propane, Dioxygen and Ammonia Activation Over Cluster Models of the Surface ab Planes of Mo-V-Te-Nb-O M1 Phase Catalyst

The mixed-metal oxide Mo-V-Te-Nb-O catalysts containing so-called M1 phase are highly promising for selective oxidation and ammoxidation of propane. Despite their promise, the fundamental understanding of these candidate catalysts is rather limited due to their highly complex nature. This in turn has hindered the progress in improving their performance required for practical applications. To optimize this catalyst, it is essential to determine the mechanism of selective propane transformation reactions occurring over this catalyst.

In this paper we report a theoretical study of propane, dioxygen and ammonia activation over cluster models of the Mo-V-Te-Nb-O M1 phase catalyst employing density functional theory implemented in VASP, GAUSSIAN03 and TURBOMOLE codes. Since the surface ab planes of the M1 phase were proposed to contain the active and selective sites, we employed cluster models of the ab plane containing all key catalytic components (Mo, V and Te) proposed for selective propane ammoxidation. We discuss the role of each metal and the influence of the active site composition (Mo/V ratio), geometry and Mo/V oxidation states in propane, dioxygen and ammonia activation over cluster models of the ab planes of the M1 phase.