2023-06-16 01:26:15
New look
In the doctoral research of Valery Muravev the researchers now shifted their focus from the metal particles to the carrier material underneath to improve the functioning of the catalyst even further. They made the ceria in different crystal sizes and immediately deposited the precious metals on it as separate atoms. They then studied how well these combinations of materials managed to bind an extra oxygen atom to carbon monoxide.
Small ceria crystals of four nanometers in size were found to be able to remarkably improve the operation of the noble metal palladium during a cold start when a lot of carbon monoxide is present. The most likely explanation for this is that the oxygen atoms are more active as the ceria crystals get smaller. Under more regular conditions, eight-nanometer ceria crystals proved to be optimal for achieving high activity at temperatures below 100 degrees Celsius.
Broader interest
This research shows for the first time that it pays not only to look at the precious metals that have to do the work when developing catalysts: varying the size of the carrier particles on which the active substances are applied offers an interesting new opportunity to catalysts and thus improve the efficiency and specificity of chemical reactions. This is also important, for example, for developing processes to convert carbon dioxide from the air into fuels or raw materials for plastics using green hydrogen.
In collaboration with the British company Johnson Matthey, which makes automotive catalysts, the scientists will now further explore how this new invention can find its way into new products.
Reference
Valery Muravev, Alexander Parastaev, Yannis van den Bosch, Bianca Ligt, Nathalie Claes, Sara Bals, Nikolay Kosinov, Emiel JM Hensen, Size of ceria support nanocrystals dictates reactivity of highly-dispersed palladium catalysts, Science(2023). DOI: 10.1126/science.adf9082.
#Cleaner #air #cold #catalyst