You can ‘hide’ methane in a cavity of an iron catalyst decorated with an organic structure and thus selectively oxidise it to methanol, according to a publication in Nature.

Methane is difficult to oxidise because of the high dissociation energy of its C–H bonds. If you want to break them, you have to use chemical tricks. Researchers at the University of Tsukuba in Japan have developed an iron catalyst that isolates a methane molecule in a hydrophobic cavity, selectively oxidises it and then repels the resulting methanol molecule.

The catalyst has several advantages. Usually catalysts are made from expensive or rare metals, but this one is made from iron, which is abundant and cheap. It is also soluble in water, which makes the reaction conditions very mild. The way it’s made helps to capture methane: the iron ion is in a hexagonal bipyramidal orientation, with large flat aromatic structures on the sides. At the top there’s an opening for water molecules to enter, and between the aromatic (and hydrophobic) structures there’s room for methane molecules. The researchers ‘anticipate that further development of this strategy might result in efficient and selective catalytic processes that can use naturally abundant carbon feedstocks.’