Chemical deactivation of Ag/Al2O3 by sulphur for the selective reduction of NOx using hydrocarbons

Controlling the Sulfur Poisoning of Ag/Al2O3 Catalysts for the Hydrocarbon SCR Reaction by Using a Regenerable SOx Trap

“…3a, dashed line) was very stable and there was no deactivation observed over 15 h. However, there is a small decrease in NO x conversion from 89 to 67% when adding 1 ppm SO 2 into the SCR gas mix. was reported in many papers, the deactivated catalysts could not easily be regenerated [5,13,17,18].…”

“…One of the promising approaches to eliminate NO x is to use the selective catalytic reduction (SCR) with hydrocarbons (HC-SCR) using silver-based catalysts . It is well-known, however, that sulphur oxides (SO x ) are detrimental to the HC-SCR activity on Ag catalysts at temperatures between about 300 and 500 °C [5,[11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

“…Moreover, these materials can be completely regenerated by a CO/CO 2 /C 3 H 6 /H 2 mixture during rich cycles at the same temperature. This is very interesting because Ag/Al 2 O 3 deactivated by SO x can also be regenerated under rich conditions at high temperatures [5,13,17,18]. Therefore, the use of Ag/SiO 2 as a SO x absorbent upstream of Ag/Al 2 O 3 during the HC-SCR reaction at intermediate temperatures (i.e.…”

Investigation of Water and Sulfur Tolerance of Precipitable Silver Compound Ag/Al2O3 Catalysts in H2-Assisted C3H6-SCR of NOx

“…22−24 Meunier et al 23 proposed that these sulfate species resulted in permanent deactivation of 1.2 wt % Ag/Al 2 O 3 in C 3 H 6 -SCR. In contrast, Houel et al 26 and Park et al 22 found that Ag/Al 2 O 3 catalysts could be regenerated after the removal of SO 2 . It was also reported that the nature of the reductant affected the performance of Ag/Al 2 O 3 in HC-SCR containing SO 2 .…”

The Role of SO3 Poisoning in CU/SSZ-13 NH3-SCR Catalysts

“…When facing real applications; however, the Cu/SSZ-13 catalysts are invariably affected by impurities, like sulfur, phosphorus, or alkali metal ions, and hence, a deep comprehension of their impacts on catalysts is very useful for their application [9][10][11][12][13][14][15]. 2 of 13 Among these impurities, sulfur poisoning is a common issue in SCR catalysts [16][17][18], and even when the amount of sulfur is quite low, sulfur exposure could result in serious deactivation of SCR activity [19]. Hence, in recent years, much work has focused on the sulfur impacts of NH 3 -SCR performance on Cu/SSZ-13 catalysts in diesel vehicles.…”