A computational strategy to improved methane activation single-atom catalysts toward ethylene formation

Abstract

Oxidative coupling of methane (OCM) is a process that aims to convert methane into higher hydrocarbons via the reaction with oxygen. Main challenges lie in activating the stable C-H bond and simultaneously achieving high selectivity toward C2 coupling reactions. Here, we propose a chemical strategy to computationally design new catalyst candidates that can activate methane and produce ethylene via OCM, focusing on single-atom doped rutile oxides. The design principle proposed in this work is aimed to address the aforementioned usual tradeoff between methane activation and C2 coupling reactions that often occurs on highly active methane conversion catalysts. Several single-atom catalysts are identified in our computational exploration, which is further verified by DFT mechanistic investigations. Energetic and geometric features that are responsible for the calculated free energies are further analyzed to understand the OCM mechanism of these catalysts to offer chemical insights.