Sol-gel preparation of mesoporous cerium-doped FeTi nanocatalysts and its SCR activity of NOx with NH3 at low temperature

Abstract

A series of cerium-doped mesoporous FeTi nanocatalysts were synthesized through a sol-gel method, and their performances for the selective catalytic reduction (SCR) of NOx with NH3 were explored. The mesoporous Ce(0.2) FeTi catalyst exhibited excellent low-temperature catalytic activity and high resistance to sulfur poisoning. A NOx conversion higher than 95 % was achieved at 200 °C over the Ce(0.2) FeTi catalyst. The strong interactions between cerium, iron oxides and titania in the Ce(0.2) FeTi catalyst resulted in a large amount of Ce3+, more active chemisorbed oxygen and more Bronsted acid sites, which contributed to the high catalytic activity for the SCR of NOx in the low-temperature region. The enhanced BET surface area and pore volume of its mesoporous structure also played an important role in its catalytic performance. Based on the DRIFTS analysis, an Eley–Rideal mechanism was proposed for the SCR over the Ce(0.2) FeTi mesoporous catalyst.