Converting methane directly into useful chemicals

RESEARCHERS have demonstrated that a gold catalyst can be used to convert methane directly into methanol and acetic acid.

Up until now, converting methane to chemicals involves steps such as syngas production, or the use of a catalyst that requires the presence of a co-reductant. These methods are costly and energy intensive. A research team led by Cardiff University, UK, has demonstrated for the first time that methane can be directly converted into methanol and acetic acid using a gold catalyst.

The catalyst was made from gold and supported on a zeolite called ZSM-5, and the team reacted methane with oxygen in the presence of the catalyst. The researchers expected the production of methanol using this catalyst, but had not expected acetic acid to be produced.

Upon inspection of the catalyst with electron microscopy, they found that the catalyst contained gold nanoparticles, which exhibit different properties to gold atoms or clusters that are typically found in gold catalysts.

Acetic acid is used to make products including textile inks, photographic chemicals, pesticides, pharmaceuticals, and plastics. Methanol is used as a biofuel and as a precursor to other chemicals.

The new catalyst doesn’t require the presence of a co-reductant, has a high selectivity to oxygenated products, and has low CO₂ production.

Graham Hutchings, Regius Professor of Chemistry from the Cardiff Catalysis Institute, said: “The oxidation of methane, the main component of natural gas, to selectively form oxygenated chemical intermediates using molecular oxygen has been a long-standing grand challenge in catalysis.

“We have successfully demonstrated this for the very first time in this study, providing an important first step towards the creation of important fuels and chemicals in a simple and cost-effective way.”

Nature Catalysis https://doi.org/hhbh