Research on structure-activity relationship dominated by template agents for mesoporous FeTi catalysts in SCR of NO with NH3

Abstract

Abstract To gain more insight into the effect of the template used for preparing FeTi catalysts for the selective catalytic reduction (SCR) of nitrogen oxide (NOx) on the catalytic structure and performance, a systematic study on FeTi catalysts synthesized using F127, CTAB, and PEG as templates is described. The catalysts exhibited outstanding performance in the SCR of NOx with NH3, exceeding that of a pure FeTi catalyst. Especially, the CTAB-modified FeTi catalyst achieved 100% of NOx conversion at 200 °C. A thorough morphological characterization showed that, compared with F127 and PEG, CTAB induced the formation of smaller catalyst particles with larger surface area, which could provide more acid sites and facilitate the adsorption of NH3, thus contributing to the enhanced activity. In addition, in-situ DRIFTS revealed that the reaction followed the Langmuir–Hinshelwood and Eley–Rideal mechanism, with the coordination of NH3 on Lewis acid sites and the bridged nitrate playing key roles in improving the catalytic performance.