In a groundbreaking discovery, University of Toronto Engineering researchers have developed a new catalyst that efficiently converts captured carbon into valuable products, even in the presence of contaminants that typically degrade the performance of existing catalysts. This advancement is a significant step towards more economically viable methods for carbon capture and storage that could be integrated into current industrial processes.
Professor David Sinton, the senior author of a paper published in Nature Energy, emphasizes the need for cost-effective techniques to capture and upgrade carbon in waste streams from industries like steel and cement manufacturing. While there have been advancements in low-carbon electricity generation, sectors that are harder to decarbonize require innovative solutions. The team at University of Toronto Engineering uses electrolyzers to convert CO2 and electricity into valuable carbon-based molecules like ethylene and ethanol, which can be used as fuels or chemical feedstocks.
Impact of Impurities on Catalyst Performance
Most catalysts developed around the world are designed to operate with a pure CO2 feed, which is not the case when dealing with carbon from industrial waste streams. One of the main challenges faced by catalysts when impurities, such as sulfur oxides like SO2, are present is the rapid degradation of efficiency. These impurities poison the catalyst surface, reducing the sites available for CO2 to react and leading to the formation of unwanted side products.
Designing a Resilient Catalyst
To address the issue of impurities like SO2, the research team at University of Toronto Engineering made two key modifications to a typical copper-based catalyst. They added a thin layer of polyteterafluoroethylene (Teflon) to one side of the catalyst, which alters the surface chemistry and inhibits SO2 poisoning. On the other side, they incorporated a layer of Nafion, an electrically-conductive polymer used in fuel cells, to create a barrier that prevents SO2 from reaching the catalyst surface.
Testing the newly designed catalyst with a mix of CO2 and SO2 at a typical industrial concentration level of 400 parts per million, the researchers achieved a Faraday efficiency of 50% that was sustained for 150 hours. This level of performance under challenging conditions demonstrates the effectiveness of the catalyst in resisting contaminants like sulfur oxides. Unlike other catalysts that experience rapid degradation when exposed to impurities, this catalyst maintained its efficiency over an extended period.
Future Applications and Challenges
The innovative approach taken by the University of Toronto Engineering team offers a promising solution not only for sulfur oxide poisoning but also for other impurities present in waste streams. While sulfur oxides are the most prevalent contaminants, there are other chemicals like nitrogen oxides and oxygen that also need to be considered. The ability of this catalyst to withstand impurities without compromising its efficiency opens up possibilities for widespread applications across various industries.
With the development of this resilient catalyst, the path towards more efficient and cost-effective carbon capture and storage techniques is becoming clearer. By overcoming the challenges posed by impurities in industrial waste streams, researchers are paving the way for a more sustainable future in carbon conversion and utilization.