Effect of HCl and o-DCBz on NH3-SCR of NO over MnO /TiO2 and MnO -CeO2/TiO2 catalysts

Interaction Mechanism Study on Simultaneous Removal of 1,2-Dichlorobenzene and NO over MnOx–CeO2/TiO2 Catalysts at Low Temperatures

“…The results indicate that the catalytic activity toward NH 3 -SCR of NO or o -DCBz catalytic oxidation varies with Ce addition contents and the optimum condition occurs on the Mn 0.15 Ce 0.1 /Ti catalyst that removed 97.1% of NO and 51.6% of o -DCBz, respectively, at 150 °C. The better catalytic activity of the Mn 0.15 Ce 0.1 /Ti catalyst than those of MnO x /TiO 2 and other MnO x –CeO 2 /TiO 2 catalysts has been explained in our previous studies. ,, The reason has been concluded that the addition of an appropriate amount of Ce increases the exposure of the Mn atom as well as the oxygen storage/release capability of the catalyst, while excessive Ce incorporates more Mn atoms into the bulk CeO 2 and decreases the redox ability and surface acidity of the catalyst instead. Therefore, the Mn 0.15 Ce 0.1 /Ti catalyst with the highest catalytic activity at low temperatures is chosen for the following simultaneous catalytic removal of NO and o -DCBz.…”

“…It can be ascribed to the residual of intermediates on the catalyst as well as the chlorination of the catalyst hinders the regeneration of surface reactive oxygen species. 22 The latter factor can be further affirmed by the new desorption peaks arising in the O 2 -TPD profiles of Mn 0.15 Ce 0.1 /Ti catalysts treated with o-DCBz. These new peaks are assigned to the desorption of the bulk lattice oxygen, whose chemical surroundings are changed probably due to the formation of O−M−Cl structures (M denotes a Mn or Ce atom).…”

“…10 ppm), indicating that the full recovery of the NH 3 -SCR reaction cannot be achieved at a temperature of 150 °C. This is possibly because the residual of the chlorine-containing byproducts from o -DCBz catalytic oxidation causes the irreversible deactivation of the catalyst . As for 250 °C, the relatively higher original NO concentration (ca.…”

“…This is possibly because the residual of the chlorine-containing byproducts from o-DCBz catalytic oxidation causes the irreversible deactivation of the catalyst. 22 As for 250 °C, the relatively higher original NO concentration (ca. 35 ppm) coincides with the lower NO conversion efficiency (shown in Figure 2) due to the overoxidation of NH 3 .…”

“…The temperature of the reactor was controlled at 150 and 250 °C using an electric tubular furnace. Gaseous o-DCBz was provided continuously using a home-made generator system, which contains a microinjection pump (TJ-3A/W0109-1B, 8,21,22 The reason has been concluded that the addition of an appropriate amount of Ce increases the exposure of the Mn atom as well as the oxygen storage/release capability of the catalyst, while excessive Ce incorporates more Mn atoms into the bulk CeO 2 and decreases the redox ability and surface acidity of the catalyst instead. Therefore, the Mn 0.15 Ce 0.1 /Ti catalyst with the highest catalytic activity at low temperatures is chosen for the following simultaneous catalytic removal of NO and o-DCBz.…”