The catalytic performances of metal-exchanged ZSM5, perovskite and γ-alumina catalysts for the reduction of nitrogen dioxide (NO2) by diesel soot were investigated. The reaction tests were performed through temperature-programmed reaction (TPR), in which NO2 and O2 were passed through a fixed bed of catalyst-soot mixture. On the three types of catalyst, NO2 was reduced to N2 by model soot (Printex-U) and most of the soot was converted into CO2. Pt-, Cu- and Co-exchanged ZSM5 catalysts exhibited reduction activities with conversions of NO2 into N2 of about 20%. Among the perovskite catalysts tested, La0. 9K0. 1FeO3 showed a 32% conversion of NO2 into N2. The catalytic activities of the perovskite catalysts were largely influenced by the number and stability of oxygen vacancies. For the γ-alumina catalyst, the peak reduction activity appeared at a relatively high temperature of around 500 °C, but the NO2 reduction was more effective than the NO reduction, in contrast to the results of the ZSM-5 and perovskite catalysts.
Bibliographical noteFunding Information:
The authors gratefully acknowledge the financial support for this work provided by SK Energy under the BK21 program of the Ministry of Education, Science and Technology (MEST), South Korea. This paper is dedicated to Professor Jae Chun Hyun on the occasion of his impending retirement from Korea University in 2010.
- Diesel Soot
- Selective Catalytic Reduction
ASJC Scopus subject areas
- Chemical Engineering(all)