A group of researchers from Yale-NUS College, in partnership with scientists in Sweden, has found that bisulfate species within the exhaust stream are strongly connected to decreasing the effectiveness of exhaust remediation catalysts in diesel engines.
Their discovery paves the way for synthesizing extra sulfur-tolerant catalysts and developing regeneration methods for catalyst systems on diesel-powered freight vehicles. This could result in lower emission of extremely toxic nitrogen oxides from diesel engines, therefore lowering pollution.
Yale-NUS College postdoctoral fellows Susanna Liljegren Bergman and Vitaly Mesilov, undergraduate researcher Xiao Yang, and Professor of Science (Chemistry) Steven Bernasek, carried out this analysis. They worked along with Sandra Dahlin and Professor Lars Pettersson in Sweden and Dr. Xi Shibo on the Singapore Synchrotron Gentle Supply of the Nationwide College of Singapore. They utilized in-situ temperature-dependent Cu K-edge X-ray absorption spectroscopy to analyze exactly how sulfur oxides affect the copper-exchanged chabazite framework (Cu-CHA) catalysts.
Catalysts composed of copper-exchanged zeolites with a chabazite framework (Cu-CHA) are presently probably the most efficient means to decrease the emission of highly poisonous nitrogen oxides from diesel engines. Nonetheless, earlier research confirmed that Cu-CHA catalysts’ efficacy is reduced by sulfur oxides that are additionally present in diesel exhaust, which c a problem as the catalysts turn into less effective at preventing nitrogen oxides from escaping into the environment.
In this research, the researchers discovered that the effectiveness of catalysts in diesel engines is most impacted by the presence or formation of bisulfates in the exhaust stream.
Understanding the chemical mechanism of how catalysts in diesel engines are affected by sulfur oxides present in diesel exhaust would allow the event of more effective catalysts that might cut down the emission of nitrogen oxides from diesel engines.