Research Suggests Cleaner Air May Be Possible with a Cold Catalytic Converter
The exhaust system of a car includes a component known as a three-way catalytic converter, which is comprised of costly materials and functions optimally within a specific temperature range of several hundred degrees Celsius.
As described in a journal article in Science, a team of scientists led by Emiel Hensen has demonstrated that modifying the carrier material of a catalyst can greatly enhance the conversion of toxic carbon monoxide into carbon dioxide, even at room temperature. The conventional three-way catalytic converters used in cars, which contain noble metals such as platinum, palladium, and rhodium on a cerium oxide substrate, require high temperatures to function effectively. However, during cold starts or when switching between powertrain modes in hybrid vehicles, toxic carbon monoxide can still be present in the exhaust gases.
Enhancing Catalyst Performance through Tailored Ceria in Cold Start and Conventional Conditions
The researchers focused on improving the catalyst by altering the carrier material, specifically the crystal size of ceria (cerium oxide). By producing ceria with smaller crystal sizes, around 4 nanometers, and depositing single-atom noble metals onto these particles, they observed a significant improvement in the catalyst’s performance under cold start conditions, where excess carbon monoxide is present. The enhanced performance was attributed to the higher reactivity of oxygen atoms on smaller ceria crystals. Under more typical operating conditions, ceria crystals with an optimal size of 8 nanometers were found to achieve high catalytic activity at temperatures below 100 degrees Celsius.
Unveiling the Power of Carrier Materials in Catalyst Development
This study highlights the importance of considering not only the noble metals but also the carrier material when developing catalysts. Manipulating the size of the particles that act as carriers for the active materials opens up new possibilities for improving catalysts, leading to enhanced efficiency and specificity in chemical reactions. This finding also has broader implications for processes involving the combination of carbon dioxide and green hydrogen for fuel production or sustainable plastics.
The researchers, in collaboration with Johnson Matthey, a British company specializing in automotive catalyst production, will further explore how to apply these findings to develop new products in the automotive industry.
Read the original article on Phys.
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