Regeneration of SO2-poisoned diesel oxidation Pd/CeO2 catalyst

Roles of ZrO2 in SO2-poisoned Pd/(Ce-Zr)O2 catalysts for CO oxidation

“…As shown in Fig. 6a, a broad band around 1145 cm −1 with shoulders at 1260 and 980 cm −1 appear in all SA samples, which can be assigned to bulk-type Ce(SO 4 ) 2 species [15,32,46,47]. Based on the fact that the peak intensity of Ce(SO 4 ) 2 becomes smaller with increasing Zr content, it can be proposed that the amount of the cerium sulfate on CeO 2 is dependent on the Ce content, in good agreement with the elemental analysis result described above.…”

“…It is reported that Pd on Ce-based support catalysts has two mechanisms for CO oxidation, depending on temperature range [46,50]. In the low temperature region, the reaction proceeds primarily between CO on Pd site and oxygen from the interface between CeO 2 and Pd (Mars and Van Krevelen mechanism, M-V mechanism) [50].…”

“…In addition, on account of interruption of redox cycle between Ce 3+ and Ce 4+ due to the formation of Ce(SO 4 ) 2 , oxygen back-spillover route from CeO 2 to Pd surface deteriorates [46]. For this reason, the low temperature oxidation (M-V mechanism) is significantly suppressed.…”

Pd supported on SnO2–MnO –CeO2 catalysts for low temperature CO oxidation

“…For instance, SO 2 present in the exhaust gas could deactivate the catalyst by forming sulfate species that can block the active sites of the catalyst [30]. Furthermore, H 2 O present in the range of 5-10 vol% in the automobile exhaust gas [31,32] has been reported to deactivate catalysts and increase the CO oxidation light-off temperature over Pd/Al 2 O 3 catalysts due to the agglomeration of Pd particles [33].…”

Promoting effect of vanadium on catalytic activity of Pt/Ce–Zr–O diesel oxidation catalysts

“…Pt-based diesel oxidation catalysts are widely used in DOC systems. However, Pt-based catalysts are expensive and easily poisoned by SO 2 in diesel exhaust (Xie et al, 2006;Corro et al, 2003;Dawody et al, 2005;Lu et al, 2008;Yoshimura et al, 2007;Zhu et al, 2013;Yang et al, 2013;Sharma et al, 2013). Moreover, activity at low temperatures also is critical for a diesel oxidation catalyst because the temperature of diesel exhaust gas is significantly lower than that of gasoline exhaust.…”