Enhanced selective catalytic reduction of NO over Mn-Ce catalysts with the acetic-acid-chelated titania support at low temperature

Abstract

In the study, we used the titania chelated with acetic acid (TAc) as the supports to prepare the highly active titania supported Mn-Ce catalysts for selective catalytic reduction of NO at low temperature. Characterization of the titania supported catalysts and the corresponding catalytic activity for NO removal were analyzed and evaluated. The TAc supported catalysts showed better Mn-Ce dispersion and catalytic activity for NO removal than the commercial TiO2 supported ones. Besides, the TAc supported catalysts also showed strong bonding at the TAc/TAc and the TAc/substrate interfaces, maintaining the integrity of the film after peeling test. We evaluated the catalytic activity for selective catalytic reduction of NO over the Mn-Ce catalysts wash-coated on ceramic monolith. Compared to the commercial TiO2 supported catalyst, the TAc supported one significantly enhanced the NO conversion by a factor of 1.25 and 1.58 times at 150 and 210°C, respectively. We speculate that the enhancement may arise from highly/uniformly-dispersed active centers on the surface of the TAc and the solidified structure of the coating layer. The well-dispersed active centers and the firm structure led to higher real space time when the NO stream flowed through the channels of the honeycombs, thereby resulting in a higher NO conversion.