▎ 摘　　要

Catalysts are needed to expedite methane-to-methanol conversion reactions by lowering the energy required for the reactions to produce high-value-added chemicals. In this work, single metal active site based on 10 different phthalocyanine-/porphyrin-functionalized graphene materials has been screened and characterized for the C-H bond activation of methane-to-methanol conversion process using ab initio density functional theory (DFT) calculations. The results show that a radical mechanism is the predominant mechanism for the C-H bond activation process of methane for these types of materials. An inverse correlation between the metal-oxo species formation energy and the C-H bond activation energy was observed, and both of them have a nice correlation with an electronic descriptor known as metal charge state of the metal-oxo species of these materials. The optimal performance of the catalysts can be attributed to the metal charge state value of the metal-oxo species, with an optimum value of 1.30 +/- 0.03. Hence, the cobalt phthalocyanine-functionalized graphene (GCoPc) system seems to be a potential candidate for optimum utilization of energy for complete methane-to-methanol conversion process. The catalytic activity of this system can further be tuned by controlling the metal charge state of Co via both substrate doping and ligand exchange.