470916 Single-Atom Active Sites for Natural Gas to Liquid Fuel Conversion
In this work, we will discuss the study of large macrocyclic molecules, transition metal phthalocyanines, as the single-atom metal active sites for the methane catalytic oxidation. The hypothesis of this work is that single-atom metal active sites (analogous to metal-oxo species of monooxygenase enzyme) can be created on a porous sheet of transition metal phthalocyanine (TMPc) deposited on 2D graphene substrate. We modeled this catalytic reaction process using ab initio density functional theory (DFT) to develop an understanding of functionalization, reaction energetics, and reaction mechanism at the atomic level. Our results indicate that this material will have significant advantages over conventional catalysts for the selective oxidation of natural gas to methanol conversion process at mild reaction condition. Our results also indicate that chemical doping of substrate can play an important role on catalytic activity of TMPc surface by donating/backdonating necessary electrons from/to the substrate and create additional activity on the active metal sites during methane oxidation reaction. This active sites will provide not only a low energy barrier for C-H bond dissociation but also a high selectivity towards the desired methanol product. This information will be helpful to develop a novel catalyst that will have significant advantages over conventional catalysts for the selective oxidation of natural gas to methanol conversion process at mild condition.
DFT calculation work was also supported from NSF-XSEDE resources under allocation number [TG-DMR140131].