Preparation of high temperature NH3-SCR catalysts with carbonate as precursors by ball milling method

Abstract

High-temperature 10Ce–2La/TiO₂ catalysts for selective catalytic reduction of NO with NH₃ were prepared by the ball milling, impregnation and co-precipitation methods and their catalytic performance was compared. The effects of different starting materials of the ball milling method on the catalytic activity were investigated. The results showed that the 10Ce–2La/TiO₂ catalyst prepared by the ball milling method using carbonates as starting materials exhibited the highest NO conversion, which was more than 80% in the temperature range of 330–550 °C. The as-prepared catalysts were characterized by XRD, TEM, and XPS. Results showed that the ball milling prepared 10Ce–2La/TiO₂ had the advantages of uniform active site distribution, high oxygen storage capacity, and high Ce³⁺ and O_α ratio. The results of NH₃-TPD and H₂-TPR showed that the ball milling method not only improved the redox ability but also increased the quantities and concentration of the acidic sites. The green production and economically viable concept of this process provides a new solution for the production application of industrial catalysts.