In a study that sounds like modern-day alchemy, scientists have finely tuned an important chemical reaction that could help us recycle carbon dioxide into plastic.
As reported in the new journal Nature Catalysis, scientists at the University of Toronto have been using a new technique that helps to pinpoint the precise conditions that convert carbon dioxide to ethylene in the most efficient way possible. Ethylene can then be processed to make polyethylene, the plastic most commonly used to make plastic bags, packaging, toys, and plastic bottles.
Although the world is gradually weaning itself off its plastic addiction, this method could help divert greenhouse gases from the atmosphere while providing a greener way to produce plastic in the first place.
"I think the future will be filled with technologies that make value out of waste. It's exciting because we are working towards developing new and sustainable ways to meet the energy demands of the future," Phil De Luna, PhD student and lead researcher, said in a statement.
The reaction is a reduction of carbon dioxide using an electrical current and a chemical reaction with the help of a copper catalyst, the only metal that can be used to produce ethylene. "Copper is a bit of a magic metal. It's magic because it can make many different chemicals, like methane, ethylene, and ethanol, but controlling what it makes is difficult," added De Luna.
Using a unique piece of equipment developed by Canadian Light Source, the team were able to study the shape and chemical environment of their copper catalyst throughout the CO2 reduction reaction. By watching this reaction unfold in real time, it allowed them to home in on the ideal conditions for maximum ethylene production, as well as reducing the output of undesirable by-products like methane.
After hours of tests and a fair share of fails, this method allowed them to craft the ideal nanostructure of copper to meet those conditions, as shown here.
"We were about to give up, but when the results came in, they were so good we had to sit down," explained PhD student Rafael Quintero-Bermudez, the paper's other first co-author.
"This has never been done before. This unique measurement allowed us to explore a lot of research questions about how the process takes place and how it can be engineered to improve."
It's likely to be a while before we start utilizing this development. Nevertheless, the study shows yet another example how researchers are using creative thinking and rigorous scientific methods to challenge the world's problems.