Concepts of Computational Approach to Explore Heterogeneous Catalysts for Direct Methane Conversion

The nonoxidative coupling of methane has attracted much attention because it yields two useful products: ethane and hydrogen. However, low conversion at low temperatures and carbon deposition at high temperatures are considered problematic. In this Concept article, a solution to these problems is presented. On the basis of the reaction enthalpy for the initial C−H bond cleavage of methane and the energy difference between C1 species (CH3 and CH) on the catalyst surface, a catalyst search guideline is provided to suppress carbon deposition while keeping the conversion rate as high as possible. Alloys are considered catalyst candidates. Few materials satisfy both of these requirements simultaneously; however, several alloys, including MgPt, are shown to be promising. The results of validation experiments for the catalytic performance of MgPt are also discussed.