New! Sign up for our free email newsletter.
Science News
from research organizations

A novel multifunctional catalyst turns methane into valuable hydrocarbons

Date:
May 29, 2024
Source:
Tokyo Institute of Technology
Summary:
The optimal design of a novel zeolite catalyst enables tandem reaction that turns greenhouse gases into value-added chemicals, report scientists. By tuning the separation between different active sites on the catalyst, they achieved the stepwise conversion of methane into methanol and then to hydrocarbons at mild conditions. These findings will help reduce energy costs and greenhouse gas emissions across various industrial fields.
Share:
FULL STORY

The optimal design of a novel zeolite catalyst enables tandem reaction that turns greenhouse gases into value-added chemicals, report scientists at Tokyo Tech. By tuning the separation between different active sites on the catalyst, they achieved the continuous conversion of methane into methanol and then to hydrocarbons at mild conditions. These findings will help reduce energy costs and greenhouse gas emissions across various industrial fields.

Methane, a greenhouse gas that contributes significantly towards global warming, is also an important source of energy and an essential chemical resource. When used as a chemical feedstock, methane is typically converted into methanol first and then into hydrocarbons. However, this sequential conversion requires complex industrial setups. More importantly, since methane is a very stable molecule, its conversion into methanol requires tremendous amounts of energy when using conventional means, such as steam methane reforming.

Against this backdrop, the catalytic conversion of methane into methanol or other chemicals has attracted much attention from scientists, who are eager to find more energy-efficient and sustainable solutions. Among recently reported catalysts, copper (Cu)-containing zeolites have shown promise for methane-to-methanol conversion at mild conditions. Unfortunately, the yield and selectivity of most reported catalysts have been low, meaning that large quantities of undesirable byproducts are generated alongside methanol.

In a recent study published in Nature Communications on March 28, 2024, a research team including Associate Professor Toshiyuki Yokoi from Tokyo Institute of Technology, Japan, investigated a new type of bifunctional zeolite catalyst. Interestingly, this Cu-containing, aluminosilicate-based zeolite is capable of converting methane and nitrous oxide, another greenhouse gas, directly into valuable compounds through a series of intermediate reactions.

One of the key questions the researchers addressed was how the spatial distribution of different active sites in the catalyst affected the output of the reactions. To this end, they prepared multiple catalysts using not only different concentrations of Cu and acid sites (proton) in aqueous solutions but also different physical mixing techniques for solid samples.

Through various experimental and analytical techniques, the researchers found that the proximity between Cu and acid sites was crucial for determining the final products. More specifically, they reported that when Cu sites were near each other, the methanol produced in Cu sites from methane had a higher probability of being overoxidized by an adjacent Cu site, turning it into carbon dioxide. In contrast, when Cu sites and acid sites were close to each other, methanol reacted with nitrous oxide in an adjacent acid site instead to produce valuable hydrocarbons and harmless nitrogen gas.

"We concluded that, for stable and efficient production of methanol and ultimately useful hydrocarbons from methane, it is necessary to uniformly distribute Cu sites and acid sites and have them be at an appropriate distance from each other," explains Yokoi. "We also found that the distribution of products obtained is also influenced by the acid properties and pore structure of the zeolite catalyst."

One of the most notable advantages of the proposed catalyst is its ability to sustain tandem reactions, that is, a simple process that merges multiple steps into one and gets rid of two different harmful greenhouse gases simultaneously. This property will be key to making such catalytic systems attractive in an industrial setting. "Our work will hopefully guide future efforts to achieve methane oxidation to methanol and open avenues for promoting hydrocarbon synthesis using methanol as an intermediate," concludes Yokoi.

With any luck, this study will serve as a stepping stone toward the decarbonization of the chemical industry, contributing to the realization of a carbon-neutral society.


Story Source:

Materials provided by Tokyo Institute of Technology. Note: Content may be edited for style and length.


Journal Reference:

  1. Peipei Xiao, Yong Wang, Lizhuo Wang, Hiroto Toyoda, Kengo Nakamura, Samya Bekhti, Yao Lu, Jun Huang, Hermann Gies, Toshiyuki Yokoi. Understanding the effect of spatially separated Cu and acid sites in zeolite catalysts on oxidation of methane. Nature Communications, 2024; 15 (1) DOI: 10.1038/s41467-024-46924-2

Cite This Page:

Tokyo Institute of Technology. "A novel multifunctional catalyst turns methane into valuable hydrocarbons." ScienceDaily. ScienceDaily, 29 May 2024. <www.sciencedaily.com/releases/2024/05/240515164151.htm>.
Tokyo Institute of Technology. (2024, May 29). A novel multifunctional catalyst turns methane into valuable hydrocarbons. ScienceDaily. Retrieved June 22, 2024 from www.sciencedaily.com/releases/2024/05/240515164151.htm
Tokyo Institute of Technology. "A novel multifunctional catalyst turns methane into valuable hydrocarbons." ScienceDaily. www.sciencedaily.com/releases/2024/05/240515164151.htm (accessed June 22, 2024).

Explore More

from ScienceDaily

RELATED STORIES