Chemists have been searching for efficient catalysts to convert methane — a major component of abundant natural gas — into methanol, an easily transported liquid fuel and building block for making other valuable chemicals. Adding water to the reaction can address certain challenges, but it also complicates the process.
José Rodriguez, an adjunct professor at Stony Brook University, is a leader of Brookhaven National Laboratory’s Catalysis Group, which has identified a new approach using a common industrial catalyst that can complete the conversion effectively both with and without water. The findings, published in the Journal of the American Chemical Society, suggest strategies for improving catalysts for the water-free conversion.
“Water is like a trick that people have been using for a long time to get this reaction going — and it definitely helps. It improves the selectivity and it aids the ability to extract the methanol,” said Rodriguez.
As shown in a recent related study by this group, adding water keeps the reaction from running away to transform the desired product, methanol, into carbon monoxide (CO) and carbon dioxide (CO2). But adding water also adds complexity and cost. Plus, at the temperatures and in the amounts required for this reaction, the water exists as large quantities of steam, which would have to be controlled in an industrial setting.
The Brookhaven team set out to explore if they could run the reaction without water by changing the catalyst — the substance that brings the reactants together and helps guide them along a particular reaction pathway.
The new paper describes how a common copper-zinc oxide catalyst can steer the reaction along different pathways depending on whether water is present.