Low-temperature selective catalytic reduction of NO on CeO₂–CuO/Al₂O₃ catalysts prepared by different methods

Abstract

CeO₂–CuO/Al₂O₃ catalysts were prepared by three different methods and their activities for selective catalytic reduction (SCR) of NO with NH₃ were investigated. As can be seen from the experimental results, the catalyst prepared by the single-step sol–gel (SG) method showed the best SCR activity and resistance to SO₂ and H₂O. In order to investigate the relationship between the preparation method and the performance of SCR catalysts, the catalysts were characterized by using Brunauer–Emmett–Teller, X-ray diffraction, temperature programmed reduction with hydrogen, temperature programmed desorption with ammonia, X-ray photoelectron spectroscopy, Fourier transform infrared and thermo-gravimetric analysis techniques. It was found that the excellent performance of CeO₂–CuO/Al₂O₃ catalyst prepared by the single-step SG method should be resulted from its large surface area, low crystallinity, high oxygen storage capacity, high NH₃ adsorption capacity, high concentration of surface chemisorbed oxygen, weak sulphation process and weak water absorption.

Keywords:

• selective catalytic reduction
• NH₃
• NO
• preparation method
• characterization

Acknowledgement

This work was supported by Scientific Problem Tackling Programme of Science and Technology Commission of Shanghai Municipality (11dz2281700).