Direct partial oxidation of methane into methanol is a cornerstone of catalysis. The stepped conversion of methane into methanol currently involves activation at high temperature and reaction with methane at decreased temperature, which limits applicability of the technique. The first implementation of copper-containing zeolites in the production of methanol directly from methane is reported, using molecular oxygen under isothermal conditions at 200 °C. Copper-exchanged zeolite is activated with oxygen, reacts with methane, and is subsequently extracted with steam in a repeated cyclic process. Methanol yield increases with methane pressure, enabling reactivity with less reactive oxidized copper species. It is possible to produce methanol over catalysts that were inactive in prior state of the art systems. Characterization of the activated catalyst at low temperature revealed that the active sites are small clusters of copper, and not necessarily di- or tricopper sites, indicating that catalysts can be designed with greater flexibility than formerly proposed.

The characterization and reactive properties of copper zeolites with twelve framework topologies (MOR, EON, MAZ, MEI, BPH, FAU, LTL, MFI, HEU, FER, SZR, and CHA) are compared in the stepwise partial oxidation of methane into methanol. Cu2+ ion‐exchanged zeolite omega, a MAZ‐type material, reveals the highest yield (86 μmol g(cat.)−1) among these materials after high‐temperature activation and liquid methanol extraction. The high yield is ascribed to the relatively high density of copper–oxo active species, which form in its three‐dimensional 8‐membered (MB) ring channels. In situ UV/Vis studies show that diverse copper species form in different zeolites after high‐temperature activation, suggesting that there are no universally active species. Nonetheless, there are some dominant factors required for achieving high methanol yields: 1) highly dispersed copper–oxo species; 2) large amount of exchanged copper in small‐pore zeolites; 3) moderately high temperature of activation; and 4) use of proton form zeolite precursors. Cu‐omega and Cu‐mordenite, with the proton form of mordenite as the precursor, yield methanol after activation in oxygen and reaction with methane at only 200 °C, that is, under isothermal conditions.

Direct partial oxidation of methane into methanol is acornerstone of catalysis.The stepped conversion of methane into methanol currently involves activation at high temperature and reaction with methane at decreased temperature,w hich limits applicability of the technique.T he first implementation of copper-containing zeolites in the production of methanol directly from methane is reported, using molecular oxygen under isothermal conditions at 200 8 8C. Copper-exchanged zeolite is activated with oxygen, reacts with methane,a nd is subsequently extracted with steam in arepeated cyclic process. Methanol yield increases with methane pressure,e nabling reactivity with less reactive oxidized copper species.I ti s possible to produce methanol over catalysts that were inactive in prior state of the art systems.C haracterization of the activated catalyst at low temperature revealed that the active sites are small clusters of copper,a nd not necessarily di-or tricopper sites,i ndicating that catalysts can be designed with greater flexibility than formerly proposed.