Quantum Chemical Modeling of the Full Catalytic Cycle for Selective Oxidation of Propane to Propene on the M1 Phase of Mo–Te–Nb–O Mixed-Metal Oxide Catalysts

In this work, we
have performed a quantum chemical study for the
selective oxidation of propane to propene on the M1 phase of a mixed-metal
oxide catalyst, consisting of Mo–Nb–Te–O. The
M1 phase of the catalyst has a complex surface structure that involves
different arrangements of metal oxide sites with variable oxidation
states. This complexity makes it inherently difficult to understand
its activity and selectivity in catalytic reactions. In this work,
we used multilayer cluster models of the main catalytic active site
of M1. We explored surface dynamics and surface oxidation by O2, oxygen vacancy formation on metal sites and the chemo- and
regioselectivity of propane activation on the surface. Our investigation
shows that linear scaling relationships to estimate free energy activation
barriers using a simple descriptor such as the hydrogen binding energy
hold true for M1. We have established a mechanistic model of the full
catalytic cycle for a radical-like pathway for propane oxidation to
propene on M1.