Continuous Synthesis of Methanol from Methane and Steam over Copper-Mordenite

One-step methane-to-methanol conversion is a dream reaction for chemists. In this Letter, continuous direct conversion of methane into methanol with steam under mild conditions using Cu(II)-exchanged mordenite is reported. The methanol production rate depended on the Si/Al ratio, Cu/Al ratio, presence of Bronsted acid sites, and O-2 concentration in the feed. Cu-H-mordenite and Cu-Na-mordenite showed comparable methane conversion rates, but the former provided higher methanol selectivity. At a given Si/Al ratio, the methane conversion rate gave a volcano plot as a function of Cu/Al ratio, and methanol selectivity decreased with increasing Cu/Al ratio. These experimental data and DFT calculation implied that binuclear copper species are more active than mononuclear copper species and that copper oxide clusters are favorable for total oxidation.

Automated summary

This Letter reports the continuous direct conversion of methane into methanol using Cu(II)-exchanged mordenite under mild conditions. The methanol production rate was influenced by factors such as the Si/Al ratio, Cu/Al ratio, presence of Bronsted acid sites, and O-2 concentration in the feed.