The poisoning effects of PbO-doped Mn-Ce/TiO2 catalysts for low temperature NH3-SCR were investigated.
Low concentration of Mn4+ and chemisorbed oxygen (Ob) were not favorable for the generation of intermediates.
The decreased Ce3+ and less reducible of manganese oxides hindered the redox cycle (Mn3+ + Ce4+ ↔ Mn4+ + Ce3+).
The doping of PbO not only altered acid sites but also inhibited ammonia adsorption as well as activation.
The poisoning of PbO resulted in the decrease of ad-NOx species (only a spot of bidentate nitrates remained).