SO₂ Poisoning of Cu-CHA deNO _x Catalyst: The Most Vulnerable Cu Species Identified by X-ray Absorption Spectroscopy.

ABSTRACT: Cu-exchanged chabazite zeolites (Cu-CHA) are effective catalysts for the NH₃-assisted selective catalytic reduction of NO (NH₃-SCR) for the abatement of NO _x emission from diesel vehicles. However, the presence of a small amount of SO₂ in diesel exhaust gases leads to a severe reduction in the low-temperature activity of these catalysts. To shed light on the nature of such deactivation, we characterized a Cu-CHA catalyst under well-defined exposures to SO₂ using in situ X-ray absorption spectroscopy. By varying the pretreatment procedure prior to the SO₂ exposure, we have selectively prepared Cu^I and Cu^II species with different ligations, which are relevant for the NH₃-SCR react

SUBMITTER: Molokova AY 

PROVIDER: S-EPMC9088759 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature