Structure–activity relationship and the inhibitory effect of sulfur dioxide and water on nitrous oxide formation in selective catalytic reduction of nitrogen oxides by ammonia over hollow Co3O4@CoMn2O4 catalyst

Hollow structures have attracted great interest in many areas for their diverse applications. In this work, a new catalyst with an open and hollow structure (Co 3 O 4 @CoMn 2 O 4 ) is designed for selective catalytic reduction of nitrogen oxides by ammonia (NH 3 -SCR). The as-prepared hollow-structured catalyst provides a high surface area and has thin shells. Owing to its structural benefits, this catalyst exhibited enhanced nitrogen oxides (NO x ) removal activity and better resistance to water and sulfur dioxide than cobalt manganate nanoparticles . It also has proved that both the Eley-Rideal and Langmuir-Hinshelwood mechanisms are present in the NH 3 -SCR process in this catalyst. The improved nitrogen selectivity after the addition of water and sulfur dioxide occurs owing to the inhibition of nitrous oxide formation through the Eley-Rideal and Langmuir-Hinshelwood mechanisms. The deep insight into the structure–activity relationship and the influence of water and sulfur dioxide on nitrogen selectivity provide a new perspective for constructing high-performance de-NO x catalysts.