Performance of Density Functional Theory for Predicting Methane-to-Methanol Conversion by a Tri-Copper Complex

Abstract

Efficient, low-temperature, and catalytic methane-to-methanol conversion (MMC) is of great interest, as methanol can be used as a liquid fuel and is a value-adding intermediate in the petrochemical industry. MMC can be achieved through direct C–H activation or via oxidation in strongly acidic media using noble metal catalysts. However, these processes are expensive and generally have low selectivity for methanol. In contrast, copper-exchanged zeolites can facilitate methane oxidation stoichiometrically under mild conditions with high selectivities for methanol. Approaches for achieving catalytic MMC on copper-exchanged zeolites have recently been developed. A better understanding of this process is required in order to facilitate the design of more efficient catalysts. In this work, we benchmark the performance of density functional theory (DFT) for modeling the MMC pathway by a tri-copper complex, [Cu3O3(H2O)6]2+. This complex is reminiscent of [Cu3O3]2+ proposed as the active-site motif in the zeolite m...