Unraveling SO2-tolerant mechanism over Fe2(SO4)3/TiO2 catalysts for NOx reduction.
J Environ Sci (China)
; 111: 340-350, 2022 Jan.
Article
en En
| MEDLINE
| ID: mdl-34949363
ABSTRACT
Developing low-temperature SO2-tolerant catalysts for the selective catalytic reduction of NOx is still a challenging task. The sulfation of active metal oxides and deposition of ammonium bisulfate deactivate catalysts, due to the difficult decomposition of the as-formed sulfate species at low temperatures (<300 °C). In recent years, metal sulfate catalysts have attracted increasing attention owing to their good catalytic activity and strong SO2 tolerance at higher temperatures (>300°C); however, the SO2-tolerant mechanism of metal sulfate catalysts is still ambiguous. In this study, Fe2(SO4)3/TiO2 and Ce2(SO4)3/TiO2 catalysts were prepared using the corresponding metal sulfate salt as the precursor. These catalysts were tested for their low-temperature activity and SO2 tolerance activity. Compared to Ce2(SO4)3/TiO2, Fe2(SO4)3/TiO2 showed significantly better low-temperature activity and SO2 tolerance. It was demonstrated that less surface sulfate species formed on Fe2(SO4)3/TiO2 and Ce2(SO4)3/TiO2. However, the presence of NO and O2 could assist the decomposition of NH4HSO4 over Fe2(SO4)3/TiO2 at a lower temperature, endowing Fe2(SO4)3/TiO2 with better low-temperature SO2 tolerance than Ce2(SO4)3/TiO2. This study unraveled the SO2-tolerant mechanism of Fe2(SO4)3/TiO2 at lower temperatures (<300 °C), and a potential strategy is proposed for improving the low-temperature SO2-tolerance of catalysts with Fe2(SO4)3 as the main active component or functional promoter.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Titanio
/
Amoníaco
Idioma:
En
Revista:
J Environ Sci (China)
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2022
Tipo del documento:
Article
País de afiliación:
China