The conversion took place at room temperature and pressure, which might allow methane, a powerful greenhouse gas, to be used to make gasoline.
According to a research published in the journal Chemical Communications, a team of researchers has successfully converted methane into methanol using light and scattered transition metals, such as copper.
As a pressure unit, the term bar comes from the Greek word meaning weight (baros). One bar equals 100,000 Pascals (100 kPa), close to the standard atmospheric pressure at sea level (101,325 Pa).
The findings of the study are a major step toward making natural gas a viable alternative fuel to gasoline and diesel. Despite the fact that natural gas is a fossil fuel, its conversion into methanol produces less carbon dioxide (CO2) than other liquid fuels in the same category.
The conversion took place under controlled conditions, which might enable methane, a powerful greenhouse gas, to be utilized to produce gasoline. Credit: UFSCAR
Methanol is important in biodiesel manufacturing and the chemical industry in Brazil, where it is used to synthesize a wide range of goods.
Methane collection from the atmosphere is also crucial in minimizing the negative consequences of climate change, since the gas has a 25-fold potential to contribute to global warming, as CO2.
Marcos da Silva, the first author of the paper, told Agência FAPESP. Silva is a Ph.D. candidate at the Federal University of So Carlos.
The project was financed by FAPESP, the Higher Research Council (CAPES, an agency of the Ministry of Education), and the National Council for Scientific and Technological Development (CNPq, a branch of the Ministry of Science, Technology, and Innovation).
The photocatalyst used in the research, according to Ivo Freitas Teixeira, a professor at UFSCar and the last author of the paper, was a major breakthrough. “This conversion occurs through the production of hydrogen and CO2 in at least two stages and under very high temperature and pressure conditions. Our ability to obtain methanol under mild conditions while also explacing less energy, is a significant accomplishment.”
Teixeira believes the findings open the way for future research into the use of solar energy for this conversion technique, potentially reducing its environmental impact even further.
The scientists used non-noble or earth-abundant transition metals, including copper, to fabricate active visible-light photocatalysts in the laboratory.
The copper-PHI catalyst triggered methane oxidation reactions by forming a large volume of oxygenated liquid products, especially methanol (2,900 micromoles per gram of material, or mol.g-1 in four hours).
Teixeira said the research provided the best catalyst and other essential conditions for the chemical reaction, such as using a large amount of water and only a small amount of hydrogen peroxide, which is an oxidizing agent. "The next steps include learning more about the active copper sites in the material and their role in the reaction itself. If successful, this would make the process even more safe and economically viable."
Another area the group will continue to research is copper. "We work with dispersed copper. When we wrote the article, we didn't know whether we were dealing with isolated atoms or clusters," he said.
The scientists used pure methane in the experiment, but they will extract the gas from renewable energy, such as biomass in the future.
Since the pre-industrial period, methane has contributed to about 30% of global warming, according to the United Nations. In the next decade, methane emissions from human activity might be reduced by as much as 45%, avoiding an increase of about 0.3°C by 2045.
The technique of using a photocatalyst to convert methane into liquid fuel is new and unobtainable on commercial markets, but its potential in the near future is significant. Teixeira said of the research carried out by researchers affiliated with universities in the United States and the United Kingdom, led by Graham Hutchings, a professor at Cardiff University in Wales.
References:
Marcos A. R. da Silva, Jéssica C. Gil, Nadezda V. Tarakina, Gelson T. S. T. Silva, Klaus Krambrock, Markus Antonietti, Caue Ribeiro, and Ivo F. Teixeira, 31 May 2022, Chemical Communications. DOI: 10.1039/D2CC01757A
Nishtha Agarwal, Simon J. Freakley, Nikolaos Dimitratos, Qian He, David J. Morgan, Robert L. Jenkins, Stuart H. Taylor, Christopher J. Kiely, and Graham J. Hutchings, Science, DOI: 10.126/science.aan6515.