Representative stock image of CO2 pollution. querbeet/iStock
The race toward carbon neutrality demands bold innovation.
Carbon dioxide, the primary culprit in climate change, is a global challenge.
Researchers have long been exploring ways to convert CO2 into valuable chemicals. One of the most promising is carbon monoxide (CO), which is a “key precursor” for creating synthetic fuels.
Existing CO2-to-CO conversion techniques suffer from costly materials, instability, low efficiency, and long processing durations (around 24 hours).
But now, researchers at Tohoku University, Hokkaido University, and AZUL Energy have enhanced this process, slashing the 24-hour processing time to just 15 minutes.
“CO2-to-CO conversion is currently a hot topic to address climate change, but the conventional techniques had major pitfalls that we wanted to address,” said Liu Tengyi (WPI-AIMR at Tohoku University).
“The materials were expensive, unstable, had limited selectivity, and took a long time to prepare. It just wouldn’t be feasible to use them in an actual industrial setting,” Tengyi added.
Fabrication method of gas diffusion electrodes modified with metal phthalocyanine crystals, and the characteristics and performance when using cobalt phthalocyanine (CoPc) crystals. ©Hiroshi Yabu et al.
CO2 conversion method
The existing conversion methods involved a complex and time-consuming 24-hour process that included mixing conductive carbon with binders, followed by drying and heat treatment.
The researchers devised an ingenious, streamlined method utilizing easily accessible and inexpensive phthalocyanines (Pcs) – organic compounds used as pigments and dyes.
For enhanced CO2-to-CO conversion, the team tested metal-free and metal-containing Pcs versions (iron, cobalt, nickel, and copper).
They applied these Pcs by spraying them onto gas diffusion electrodes, creating direct crystalline layers on the surface.
Among the tested materials, cobalt phthalocyanine (CoPc) demonstrated the best efficiency in converting CO2 to CO.
“This graffiti-like method of simply spraying the catalyst on a surface reduces the typical processing time down to a mere 15 minutes,” the press release noted.
Carbon monoxide’s key role in fuel is as an intermediate within gas mixtures such as syngas and producer gas, which are further utilized or transformed into safer and more convenient fuels.
Best catalyst for producing CO
The new conversion method demonstrated long-term stability by maintaining consistent performance for 144 hours under a current density of 150 mA/cm².
This sustained operation under relevant electrochemical conditions suggests the system’s potential for practical and continuous application.
Furthermore, the advanced structural analysis revealed the secret behind this remarkable performance: the direct crystallization of the phthalocyanines led to densely packed molecules. As a result, the efficient flow of electrons necessary for the conversion was achieved.
“Not only is this the best Pc-based catalyst for producing CO to date, but it successfully exceeds the industrial standard thresholds for its reaction rate and stability. It’s the first ever to make the cut,” added Liu in the press release.
Therefore, this technology has significant potential as a next-generation solution for Carbon Dioxide Capture and Utilization (CCU).
Last year, Interesting Engineering reported on the development of a lotus-inspired method to turn carbon dioxide into useful products.
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Inspired by the water-repelling properties of the lotus plant, the University of Central Florida (UCF) developed a device for conversion. This technology offers a dual benefit: reducing carbon emissions from human activities and sustainably generating more energy.
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ABOUT THE EDITOR
Mrigakshi Dixit Mrigakshi is a science journalist who enjoys writing about space exploration, biology, and technological innovations. Her work has been featured in well-known publications including Nature India, Supercluster, The Weather Channel and Astronomy magazine. If you have pitches in mind, please do not hesitate to email her.
