Assistant professor of materials chemistry Ruigang Wang is conducting research to help improve vehicle catalytic conversion systems thanks to a $200,640 grant from the National Science Foundation.
The main part of Wang’s research focuses on catalytic conversion systems, which convert toxic or harmful byproducts — such as carbon monoxide, nitrogen oxides and hydrocarbons — in the exhaust of an internal combustion engine to less toxic substances by way of catalyzed chemical reactions.
The converter works by turning carbon monoxide to carbon dioxide, nitrogen oxides to nitrogen, and hydrocarbons to water and carbon dioxide.
Oxide-supported metal catalyst is used for these catalytic conversion reactions. The commercial oxide support, CeO2, will always be an octahedral shape, making it difficult to extract oxygen for the two oxidation reactions so the converter has to be heated up to almost 800 degrees in order to do the extraction. The goal for this project is to control the shape and the size of the CeO2 support nanoparticles and these CeO2 nanorods/nanocubes could release oxygen at much lower temperature compared to the octahedral shape CeO2, which would mean that the materials could be used at a lower temperature.
“In the winter, for example, when you start your engine, because the temperatures are so low and the catalysts cannot work. Most of the exhaust gases cannot be converted into unpolluted gases,” Wang said.
Most commercial systems available use noble metals, such as platinum, palladium and rhodium. Based on the improved catalytic activity of CeO2 support by controlling the shape, Wang is also trying to find a way to replace those expensive metals with inexpensive transition metals such as nickel, cobalt and copper.
Six graduate students will help Wang with his research on this three-year long project.