Promotional effect of acidic oxide on catalytic activity and N2 selectivity over CeO2 for selective catalytic reduction of NOx by NH3

The CeO2, CeO2-ZrO2 and CeO2-WO3 catalysts were prepared by hydrothermal method and used to the selective catalytic reduction of NOx by NH3. The addition of ZrO2 or WO3 into CeO2 was favorable for pore structure, and then improved the number of active sites. Besides, the introduction of ZrO2 into CeO2 could improve the Lewis acid sites while WO3 could contribute to the generation of BrOnsted and Lewis acid sites, which could improve the catalytic performance and N-2 selectivity. The CeO2-WO3 catalyst exhibited optimal catalytic activity with above 90% NOx conversion performance at 220-425 degrees C and approximately 100% N-2 selectivity at 150-425 degrees C.