New Delhi: Can carbon dioxide (CO2)—a greenhouse gas whose high emissions contribute to global warming—be turned into usable energy? Scientists believe this can be done. They are now one step closer to making it a reality, and claim to have identified a “new electrocatalyst that efficiently converts CO2 to carbon monoxide (CO), a highly energetic molecule”.
The study by a team of researchers including scientists at the US department of energy’s (DOE) Brookhaven National Laboratory was published in February in international journal Energy & Environmental Science.
“There are many ways to use CO … You can react it with water to produce energy-rich hydrogen gas, or with hydrogen to produce useful chemicals, such as hydrocarbons or alcohols. If there were a sustainable, cost-efficient route to transform CO2 to CO, it would benefit society greatly,” Eli Stavitski, a scientist at Brookhaven and an author on the paper, said in a statement on Thursday.
The findings are significant as “scientists from long have sought a way to convert CO2 to CO but traditional electrocatalysts cannot effectively initiate the reaction. That’s because a competing reaction, called the hydrogen evolution reaction (HER) or water splitting takes precedence over the CO2 conversion reaction,” the study explained.
“A few noble metals, such as gold and platinum, can avoid HER and convert CO2 to CO. However, these metals are relatively rare and too expensive to serve as cost-efficient catalysts. So, to convert CO2 to CO in a cost-effective way, scientists used an entirely new form of catalyst. Instead of noble metal nanoparticles, they used single atoms of nickel,” the study highlighted.
Haotian Wang, a Rowland Fellow at Harvard University and the corresponding author on the study, said, “Nickel metal, in bulk, has rarely been selected as a promising candidate for converting CO2 to CO.”
The study, however, said that “single atoms of nickel produce a different result”.
“Single atoms prefer to produce CO, rather than performing the competing HER, because the surface of a bulk metal is very different from individual atoms,” Stavitski added.
The study stressed that the scientists discovered that “single nickel atoms catalyzed the CO2 conversion reaction with a maximal of 97% efficiency” and according to scientists, “this is a major step toward recycling CO2 for usable energy and chemicals.”
“To apply this technology to real applications in the future, we are currently aimed at producing this single atom catalyst in a cheap and large-scale way, while improving its performance and maintaining its efficiency,” Wang added.