A group of researchers have found a new and simpler way to convert carbon dioxide into more usable fuels and other chemicals. The team, led by Professor Ted Sargent of the University of Toronto’s Faculty of Applied Science & Engineering, have discovered a more efficient way to harvest and convert the gas, thus reducing the amount of CO2 left in the Earth’s atmosphere, using nanoengineering.
For billions of years, carbon dioxide has been an important trace gas in the atmosphere of this planet, playing a vital role in the regulation of our world’s surface temperature, as an integral part of the carbon cycle, and is essential for maintaining the Earth’s present biosphere.
However, constant increases in CO2 emissions, along with other greenhouse gasses, since the advent of the industrial revolution have seen carbon dioxide levels rise to more than 40% over the mean levels of the last 10,000 years. Pockets of ancient air found frozen in ice have shown that CO2 levels normally hovered around the 200-280 parts per million level throughout the last half-million years. CO2 levels in 2015 reached a high of 402 ppm, possibly the most concentrated level in the last 20 million years, and are said to be the main causes of climate change and ocean acidification. The continued burning of fossil fuels, coupled with ongoing deforestation, creates an excess of CO2 that is too great to be absorbed by the world’s plants and oceans.
Drs. Min Liu and Yuanjie Pang, along with a research team of graduate students and post-doctoral fellows, have developed a new technique that uses by renewable energy, such as solar power or wind, to take climate-warming carbon dioxide and convert it to carbon monoxide, that can then be used to make carbon-based chemical fuels, such as methanol, ethanol, and diesel.
“CO2 reduction is an important challenge due to the inertness of the molecule,” says Liu. “We were looking for the best way to both address mounting global energy needs and help the environment,” adds Pang. “If we take CO2 from industrial flue emissions or from the atmosphere, and use it as a reagent for fuels, which provide long-term storage for green energy, we’re killing two birds with one stone.”
The team’s process involves fabricating extremely tiny ‘nanoneedles’ out of gold, each with a tip 10,000 times thinner than a human hair, which then, “… act like lightning rods for catalyzing the reaction,” according to Liu.
A small electrical bias is then applied to the array of nano-needles, which attracts carbon dioxide and accelerates its reduction to carbon monoxide faster than any previous catalyst. This breakthrough in selectivity and efficiency could bring CO2 reduction closer to the realm of commercial electrolysers.
This CO can then be used to produce more conventional fuels, helping deal with the population’s demands for renewable energy and provide a use for the currently abundant amounts of carbon dioxide out there.