COLUMBUS, Ohio (WCMH) — Future catalytic converters could be designed to scrub pollutants for a longer period and need fewer rare materials to operate, a new study suggests.
A good catalytic converter can last for more than 10 years — if thieves don’t saw it off the vehicle first. Rising prices for the three precious metals found in the converters, especially rhodium, which is found in river sands of North and South America, is why criminals steal them, according to a media release from OSU.
“We want to have a better lifetime for catalytic converters. Otherwise, they will have to be replaced or won’t pass the government’s emission tests,” said Cheng-Han Li, a doctoral student in materials science and engineering at The Ohio State University and lead author of the study published in Chemistry of Materials.
The catalysts have been known to deactivate at high temperatures. At high heat with oxygen, rhodium dissolves into the alumina and degrades into the stable solution rhodium aluminate. This solution is chemically inactive; it can’t scrub away harmful pollutants and gases, making the catalytic converters useless, the media release said.
Hydrogen exposure reactivates some of the rhodium but not nearly enough to return the catalytic converter to its former efficiency.
The study’s findings concluded that in the long run, establishing a new design that prevents the formation of rhodium aluminate could help get the most out of the catalytic converters.
“Our results give car manufacturers a specific direction to follow to optimize the use of rhodium-based catalysts,” said Li.
Co-authors were Jason Wu, Andrew Bean Getsoian and Giovanni Cavataio of the Ford Motor Company, and Joerg Jinschek, an associate professor of materials science and engineering at OSU. This study was funded by the OSU-Ford Alliance Project.