鶹Ƶ scientists solve puzzle of converting CO₂ emissions to fuel
Published: August 25, 2016
Every year, humans advance climate change and global warming – and quite likely our own eventual extinction – by injecting about 30 billion tonnes of carbon dioxide (CO₂) into the atmosphere.
A team of 鶹Ƶ scientists believes they’ve found a way to convert all these emissions into energy-rich fuel in a carbon-neutral cycle that uses a very abundant natural resource: silicon. Silicon, readily available in sand, is the seventh most-abundant element in the universe and the second most-abundant element in the earth’s crust.
The idea of converting CO₂ emissions to energy isn’t new: there’s been a global race to discover a material that can efficiently convert sunlight, carbon dioxide and water or hydrogen to fuel for decades. However, the chemical stability of CO₂ has made it difficult to find a practical solution.
“A chemistry solution to climate change requires a material that is a highly active and selective catalyst to enable the conversion of CO₂ to fuel. It also needs to be made of elements that are low cost, non-toxic and readily available,” said Faculty of Arts & Science chemistry professor Geoffrey Ozin, the Canada Research Chair in Materials Chemistry and lead of 鶹Ƶ’s Solar Fuels Research Cluster.
In an, Ozin and colleagues report silicon nanocrystals that meet all the criteria. The hydride-terminated silicon nanocrystals – nanostructured hydrides for short – have an average diameter of 3.5 nanometres and feature a surface area and optical absorption strength sufficient to efficiently harvest the near-infrared, visible and ultraviolet wavelengths of light from the sun together with a powerful chemical-reducing agent on the surface that efficiently and selectively converts gaseous carbon dioxide to gaseous carbon monoxide.
The potential result: energy without harmful emissions.
“Making use of the reducing power of nanostructured hydrides is a conceptually distinct and commercially interesting strategy for making fuels directly from sunlight,” said Ozin.
The 鶹Ƶ Solar Fuels Research Cluster is working to find ways and means to increase the activity, enhance the scale, and boost the rate of production. Their goal is a laboratory demonstration unit and, if successful, a pilot solar refinery.
In addition to Ozin, collaborators on the paper include:
- Le He, Chenxi Qian, Laura Reyes, Wei Sun and P.Y. Wong – Department of Chemistry, Faculty of Arts & Science;
- Abdinoor Jelle and Jia Jia – Department of Chemistry, Faculty of Arts & Science and Department of Materials Science & Engineering, Faculty of Applied Science & Engineering;
- Kulbir Kaur Ghuman, Department of Materials Science & Engineering, Faculty of Applied Science & Engineering;
- Chandra Veer Singh – Department of Materials Science & Engineering and Department of Mechanical & Industrial Engineering, Faculty of Applied Science & Engineering;
- Charles A. Mims, Paul G. O’Brien and Thomas E. Wood – Department of Chemical Engineering & Applied Chemistry, Faculty of Applied Science & Engineering, and Solar Fuels Research Cluster;
- Amr S. Helmy – Edward S. Rogers Sr. Department of Electrical & Computer Engineering, Faculty of Applied Science & Engineering.
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