Low-Temperature Catalytic Selective Oxidation of Methane to Methanol

Abstract

The selective oxidation of methane, which is the primary component of natural gas, is one of the most important challenges in catalysis. While the search for catalysts capable of converting methane directly to higher value commodity chemicals and liquid fuels, such as methanol, has been ongoing for over a century, an industrially viable process has not yet been developed. In nature, this process is selectively demonstrated by methane monooxygenase using dioxygen at room temperature, but such a process has not been commercialised. Currently, large scale upgrading of natural gas proceeds indirectly by employing high-temperature conversion to syngas which is then processed to synthesis fuels and chemicals. Other routes for methane activation include gas-phase oxidative and non-oxidative coupling to form higher hydrocarbons and aromatic compounds, and liquid-phase oxidation to methanol, formaldehyde and acetic acid. Low-temperature selective oxidation of methane to methanol has also been widely studied and remains an open challenge for catalysis in the twenty-first century.