New approach to reduce carbon dioxide could be golden solution to pollution

Reducing carbon dioxide (CO₂) to carbon monoxide (CO) through an electrochemical reaction holds strong potential for removing CO₂ from the atmosphere to reduce pollution and for producing alternative energy with carbon monoxide as an ingredient. However, the current catalysts used in electrochemical carbon dioxide reduction reaction (CO₂RR) are not efficient or selective enough to make CO₂RR a practical solution. Now, a team of researchers from Fujian Institute of Research on the Structure of Matter of Chinese Academy of Sciences has developed a gold-based hybrid material by modifying gold nanoparticles with a macrocyclic compound called cucurbit[6]uril (CB[6]) that allows for more efficient CO₂RR than previously possible.

The results were published in Nano Research on December 05, 2022.

"With this work, we hoped to solve the problem of environmental pollution and energy shortage through electrochemical conversion of carbon dioxide to value-added products," said corresponding author Minna Cao of the State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and of the University of Chinese Academy of Sciences. "In order to enhance the local CO₂ concentration on the catalysts' surface, we utilize macromolecule cucurbit[n]uril to functionalize gold surface, which is the distinguishing feature of our work from those that has been done before."

According to the researchers, gold is known to be highly active in converting CO₂ to CO relative to other catalysts. However, the binding energy of both CO₂ and CO to the gold catalyst surface is positively correlated, which clashes with the need in CO₂RR for CO₂ adsorption and CO desorption, since the CO desorption does not occur due to the positive correlation of its binding energy to the catalyst.

The researchers created a controlled synthesis of nanoparticles by modifying CB[6]. CB[6] has negatively charged portals and positively charged surface, which helps contribute to the result of having the electronic interaction between CB[6] and metal regulate the catalytic performance.