Computationally Exploring Confinement Effects in the Methane-to-Methanol Conversion Over Iron-Oxo Centers in Zeolites

Transition metal-oxo centers in zeolites are known to be active in the conversion of methane to methanol. In this work, we examine this reaction over Fe-oxo sites in the zeolite SSZ-13. By comparing calculations for the fully periodic structure and a cluster for two different methods—the standard van der Waals corrected semilocal density functional PBE-D2 and ACFDT-RPA, which is a method where correlation is calculated fully nonlocally—we find that it is actually the confining environment in the zeolite that reduces the barrier for this reaction, by more than 50%, and we find that the two applied methods lead to qualitatively different ends.