Scientists have developed a catalyst that can curb emissions of nitrogen oxides from diesel-powered vehicles, an advance that may help reduce air pollution and smog.
Nitrogen oxides (NOx) is a priority air pollutant that is a key ingredient in smog.
“Diesel engines power virtually all heavy-duty trucks, and NOx emissions control remains one of the key challenges facing manufacturers and operators,” researchers said.
The team focussed on copper-exchanged zeolites, a particular class of catalysts used to promote the conversion of NOx into environmentally benign nitrogen gas.
“We knew that copper ions, trapped in the zeolite pores, were responsible for the catalytic reaction...” said William Schneider from University of Notre Dame in the US.
Reducing exhaust
They discovered that the ions were much more mobile than anyone had appreciated, so much so that they were able to swim through the zeolite pores and pair up. They were able to combine the experiments and computations to quantify the pairing and its influence on NOx removal.
“This information paves the way to developing catalysts that outperform current formations at lower temperatures, allowing diesel engines to meet stringent emissions regulations,” said Schneider.
The study was published in the journal Science.