Promoting Effect of Coexisting H2O on the Activity of Ir/WO3/SiO2 Catalyst for the Selective Reduction of NO with CO.

The catalytic activity of Ir/WO₃/SiO₂ for the selective reduction of NO with CO (CO-SCR) in the presence of excess O₂ was significantly increased by the presence of coexisting H₂O, whereas NO reduction hardly occurred in the absence of H₂O. Coexisting H₂O plays an important role preventing catalyst deactivation caused by oxidation of the catalytically active Ir sites at high temperatures. [ABSTRACT FROM AUTHOR]