Methane To Methanol Directly

A metal-doped zeolite facilitates direct conversion of methane to methanol in aqueous media, according to a group led by chemists at Cardiff University, in Wales (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201108706). Methane, the main component of natural gas, is relatively plentiful in many parts of the world, but it is often found in remote locations lacking transportation infrastructure. Researchers would like to be able to convert the gas directly to shippable liquid fuels and chemicals such as methanol, but direct and commercially viable conversion methods remain elusive. Currently, methane is converted to methanol via an energy-intensive two-step process involving synthesis gas (CO and hydrogen). Cardiff’s Ceri Hammond and Graham J. Hutchings, together with coworkers in academia and at Dow Chemical, report that aqueous H₂O₂ oxidizes methane to methanol with greater than 90% selectivity in the presence of zeolite ZSM-5 doped with copper and iron, a stable and reusable catalyst. The iron centers convert H₂O₂ to a species that activates C–H bonds, and copper inhibits overoxidation of methanol to formic acid and CO₂, the team says.