DeNOx performance enhancement of Cu-based oxides via employing a TiO2 phase to modify LDH precursors

Abstract

CuAl-LDO, CuAl-LDO/TiO₂ and CuAl-LDO/TiO₂NTs catalysts were obtained from TiO₂ modified LDHs precursor which were prepared by in situ assembly method. Then catalysts were evaluated in the selective catalytic reduction of NO_x with NH₃(NH₃-SCR), and the results showed that the CuAl-LDO/TiO₂NTs catalyst exhibited preferable deNO_x performance (more than 80% NO_x conversion and higher than 90% N₂ selectivity at a temperature range of 210–330 °C) as well as good SO₂ resistance. With the aid of series of characterizations such as XRD, N₂ adsorption/desorption, XPS, NH₃-TPD, H₂-TPR, and in situ DRIFTS, it could be concluded that, doping TiO₂NTs afforded the catalyst larger specific surface area, more abundant surface chemisorption oxygen species and more excellent redox performance. Meanwhile, In situ DRIFTS evidenced that CuAl-LDO/TiO₂NTs catalyst has a strong adsorption capacity for the reaction gas, which is more conducive to the progress of the SCR reaction.