Effect of Ceria on the Sulfation and Desulfation Characteristics of a Model Lean NO x Trap Catalyst

Abstract

The effect of ceria addition on the sulfation and desulfation characteristics of a model Ba-based lean NO x trap (LNT) catalyst was studied. According to DRIFTS and NO x storage capacity measurements, ceria is able to store sulfur during catalyst exposure to SO 2 , thereby helping to limit sulfation of the main (Ba) NO x storage phase and maintain NO x storage capacity. Temperature programmed desulfation experiments revealed that desulfation of a model ceria-containing catalyst occurred in two stages, corresponding to sulfur elimination from the ceria phase at *450°C, followed by sulfur loss from the Ba phase at *650°C. Significantly, the ceria-containing catalyst displayed relatively lower sulfur evolution from the Ba phase than its non-ceria analog, confirming that the presence of ceria lessened the degree of sulfur accumulation on the Ba phase.

Synthesis and Physico-Chemical Characterization of CeO2/ZrO2-SO42- Mixed Oxides

“…Mixed oxide catalysts have received tremendous attention both in fundamental and industrial point of view because of their wide spread utility in the chemical industry in comparison with bulk oxide catalysts [1]. The synthesis and development of materials with enhanced thermal, redox and acid-base properties are of paramount interest in designing and selecting catalysts for specific catalytic reactions [2][3][4][5][6]. Recently, a new generation of mixed oxides containing CeO 2 and ZrO 2 with the features previously mentioned has been developed [7][8][9][10].…”

Effects of temperature and reductant type on the process of NOx storage reduction over Pt/Ba/CeO2 catalysts

“…However, most of the previous studies focused on the structure characterization or NO x storage capacity testing of the catalyst [12][13][14][15][16][17][18][19], without considering both lean and rich stages of NSR process. As more emphasis has been paid on the reduction process of typical NSR catalyst, we tried to give a realistic evaluation of catalytic behavior for ceria supported catalysts by using different reductants.…”

SOx storage and release kinetics for ceria-supported platinum

“…Other concepts based on, for example, incorporation of SO x trapping materials in the NSC formulation that can store and release SO x under lean and rich conditions, respectively, have also been reported [6,7]. Such systems, however, are not treated here.…”