Study on the Mechanism of SO<sub>2</sub> Poisoning of MnO<sub>x</sub>/PG for Lower Temperature SCR by Simple Washing Regeneration

Manganese oxide-supported palygorskite (MnO<sub>x</sub>/PG) catalysts are considered highly efficient for low-temperature SCR of NO<sub>x</sub>. However, the MnO<sub>x</sub>/PG catalyst tends to be poisoned by SO<sub>2</sub>. The effect of SO<sub>...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Xianlong Zhang, Shiwen Liu, Kang Ma, Yazhong Chen, Shi Jin, Xinyu Wang, Xueping Wu
Formato: article
Lenguaje:EN
Publicado: MDPI AG 2021
Materias:
Acceso en línea:https://doaj.org/article/7183cad77f794f51bcf4507b1f74efa6
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
Descripción
Sumario:Manganese oxide-supported palygorskite (MnO<sub>x</sub>/PG) catalysts are considered highly efficient for low-temperature SCR of NO<sub>x</sub>. However, the MnO<sub>x</sub>/PG catalyst tends to be poisoned by SO<sub>2</sub>. The effect of SO<sub>2</sub> on activity of the SO<sub>2</sub>-pretreated poisoning catalysts under ammonia-free conditions was explored. It was determined that the MnO<sub>x</sub>/PG catalyst tends to be considerably deactivated by SO<sub>2</sub> in the absence of ammonia and that water-washed regeneration can completely recover activity of the deactivated catalyst. Based on these results and characterizations of the catalysts, a reasonable mechanism for the deactivation of MnO<sub>x</sub>/PG catalyst by SO<sub>2</sub> was proposed in this study. SO<sub>2</sub> easily oxidized to SO<sub>3</sub> on the surface of the catalyst, leading to the formation of polysulfuric acid, wrapping of the active component and blocking the micropores. The deactivation of the MnO<sub>x</sub>/PG catalyst is initially caused by the formation of polysulfuric rather than the deposition of ammonia sulfate, which occurs later.