Effect of gas composition on the selective reduction of NOx with ammonia over Vanadia based catalysts

Year 2018, Volume: 1 Issue: 2, 3 - 12, 01.04.2018

Souad Djerad , Marcus Crocoll Lakhdar Tifouti Werner Weisweiler

Abstract

The catalytic reduction of
NO_x under different oxygen concentrations leading to different NO/NO₂
compositions has been studied in the presence of V3W9Ti and V8W9Ti catalysts in
a tubular flow reactor. The results have shown that increasing O₂
concentration leads to increase the NO_x reduction in low temperature
range [150-275 °C]. Slight effect of O₂ concentration on NO_x
conversion was observed at higher temperatures. SCR reaction also occurred in
the absence of gaseous oxygen but with low NO conversion indicating the strong
redox properties of both catalysts. Aged catalysts exhibited relative good activities
in NO_x reduction. This is probably due to the sol gel method used
for the preparation of the catalysts known to improve the catalysts properties.

Keywords

SCR; Oxygen concentration; NO-NO2 mixture; Ammonia oxidation; TPD; Aging.

References

• J. Jiang, D. Li, Theoretical analysis and experimental confirmation of exhaust temperature control for diesel vehicle NOx emissions reduction, Applied Energy 174, 232-244, 2016.
• S. Djerad, M. Crocoll, S. Kureti, L. Tifouti, W. Weisweiler, Effect of oxygen concentration on the NOx reduction with ammonia over V2O5–WO3/TiO2 catalyst, Catalysis Today 113, 208, 2006.
• A. Marberger, D. Ferri, M. Elsener, A. Sagar, C. Artner, K. Schermanz, O. Kröcher, Relationship between structures and activities of supported metal vanadates for the selective catalytic reduction of NO by NH3, Applied Catalysis B: Environmental 218, 731-742, 2017.