A team of researchers has revealed how certain zeolites, an ordinary crystalline material, could convert methane into methanol at room temperature, possibly paving the way to the cleaner production of methanol.
The team, led by chemists at Stanford University, based their research on findings in the 1990s by Russian scientists that when synthetic zeolites made with iron are exposed to methane gas, they immediately start cranking out methanol, even at room temperature.
The process, as opposed to the high temperatures and pressures needed for the current methanol production, means "iron zeolites are promising catalysts for low-temperature methane conversion," said Edward Solomon, a professor of chemistry at Stanford and co-author of a study published in Nature.
Consisting primarily of aluminum, silicon and oxygen, zeolites have porous molecular structure that enables them to trap pet odors and unwanted particles, like radioactive waste, and are used as catalysts to make gasoline, diesel fuel and petrochemical products.
They are "inexpensive and used in everything from catalysts to cat litter," noted graduate student Benjamin Snyder, co-lead author of the study.
To locate where catalysis occurs, the research team applied a series of advanced spectroscopy techniques to pinpoint the active site in the iron zeolites and create detailed computational models of its structure.
"We found that the iron core of the active site is locked in an unusual, constrained geometry by the zeolite crystal, and this leads to exceptional reactivity with methane," Snyder was quoted as saying in a Stanford news release.
Saying that understanding the relationship between catalyst structure and reactivity is a crucial first step in developing environmentally friendly catalysts at scale, Snyder acknowledged that there are many technical hurdles to overcome.
"Perhaps one day we'll be able to convert natural gas to methanol right at the point of extraction, without having to transport the gas to industrial-scale plants that require a massive input of energy," he said. "That technology may be many years off, but our findings represent an important step forward."
