Promotional effect of acidic oxide on catalytic activity and N₂ selectivity over CeO₂ for selective catalytic reduction of NO_<i>x</i> by NH₃

Abstract

The CeO 2 , CeO 2 ‐ZrO 2 and CeO 2 ‐WO 3 catalysts were prepared by hydrothermal method and used to the selective catalytic reduction of NO x by NH 3 . The addition of ZrO 2 or WO 3 into CeO 2 was favorable for pore structure, and then improved the number of active sites. Besides, the introduction of ZrO 2 into CeO 2 could improve the Lewis acid sites while WO 3 could contribute to the generation of Brønsted and Lewis acid sites, which could improve the catalytic performance and N 2 selectivity. The CeO 2 ‐WO 3 catalyst exhibited optimal catalytic activity with above 90% NO x conversion performance at 220–425 °C and approximately 100% N 2 selectivity at 150–425 °C.