The balance of acidity and redox capability over modified CeO2 catalyst for the selective catalytic reduction of NO with NH3.
J Environ Sci (China)
; 79: 273-279, 2019 May.
Article
em En
| MEDLINE
| ID: mdl-30784451
ABSTRACT
The effect of acidity and redox capability over sulfuric acid-modified CeO2 catalysts were studied for the selective catalytic reduction of NOx with NH3 (NH3-SCR). The deposition of sulfate significantly enhanced the catalytic performance over CeO2. NOx conversion over 4H2SO4/CeO2 at 230-440⯰C was higher than 90%. The strong redox capability of CeO2 could result in unselective NH3 oxidation and decrease high temperatures catalytic activity and N2 selectivity. The deposition of sulfate increased the acidity and weakened the redox capability, and then increased the high temperature NOx conversion and N2 selectivity. An appropriate level of acidity also promoted the activity at 190-250⯰C over ceria-based catalysts, and with further increase in the acidity, the SCR activity decreased slightly. Weak redox capability lowered the low-temperature catalytic activity. Excellent SCR activity requires a balance of acidity and redox capability on the catalysts.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sulfatos
/
Cério
/
Poluentes Atmosféricos
/
Amônia
/
Óxido Nítrico
Idioma:
En
Revista:
J Environ Sci (China)
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2019
Tipo de documento:
Article