Methane Transformation over Copper-Exchanged Zeolites: From Partial Oxidation to C-C Coupling and Formation of Hydrocarbons

Direct methane conversion to methanolviachemical looping using copper-exchanged zeolites has attracted considerable attention during the last decades and is one of the most-actively studied processes. Despite the significant progress that has been made in the design of active systems and the elucidation of active sites, the effects of zeolite topology and the structure of copper species on the nature of the reaction products are yet unclear. Herein, we show that oxygen-activated copper-exchanged zeolites of different framework types, namely, MOR, MFI, BEA, and FAU, yield different products, as detected byin situFourier-transform infrared and nuclear magnetic resonance spectroscopy. Molecular methanol, methoxy species, and dimethyl ether prevail at lower reaction temperatures (