Work

Rare earth metals as bi-functional sites in Cu-SSZ-39 catalysts for promotion of phosphorous and HCs resistance

Year: 2024

Type: article

Abstract: The abatement of NO x from diesel vehicle exhaust is of great importance for improving the atmospheric environment. Cu-SSZ-39 zeolites possess the potential for application in the diesel vehicle aftertreatment system. Phosphorus (P) and hydrocarbons (HCs) present in the exhaust have negative impacts on the catalysts. To enhance the resistance of Cu-SSZ-39 catalysts to P and HCs, various rare earth metals were doped. Loading of 1 wt% Ce on the Cu-SSZ-39 catalyst improves the resistance to P and HCs simultaneously. The promotion mechanism was investigated through H 2 -temperature programmed reduction (H 2 -TPR), ultraviolet visible diffuse reflectance spectroscopy (UV–vis-DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and theoretical calculation. On the one hand, Ce species can act as sacrificial sites, preferentially binding with P. On the other hand, Ce doping induces the formation of CuO species, promoting the oxidation of C 3 H 6 and preventing the consumption of NH 3 from the reaction with C 3 H 6 . Ce acting as bi-functional sites enhances the P and HCs resistance of Cu-SSZ-39 catalysts, further brightening its practical application.

Source: Journal of Rare Earths

DOI: 10.1016/j.jre.2024.12.006