NOx storage and reduction performance of Pt–CoOx–BaO/Al2O3 catalysts: Effects of cobalt loading and calcination temperature

Non-thermal plasma assisted NO storage and reduction over a cobalt-containing Pd catalyst using H2 and/or CO as reductants

“…Additionally, the lower precious metal dispersion of Pd/Ba/Al (Pd, 32.0%) compared to the Pt/Ba/Al sample (Pt, 41.9%, see Table 2) can also be expected to negatively impact its NO x storage properties given that the dispersion of Pt or Pd in LNT catalysts has been shown to significantly influence NO x storage capacity [39]. Compared with Pt/Ba/Al and Pd/Ba/Al, it is clear that the Pd/Co/Ba/Al sample possessed much higher NO x storage capacity over the full operating temperature range (150-350 • C), indicating that the presence of the cobalt as the main NO oxidation component (and barium as the chief NO x storage component) significantly improved NO x storage capacity, in agreement with the findings of Hu [21] and Wang et al [23].…”

“…In this manner high NO x conversions could be achieved over the LaMn 0.9 Fe 0.1 O 3 catalyst, even at room temperature. Aside from perovskites, a number of simple transition metal oxides with strong oxidation activity and low expense have attracted attention for LNT applications, cobalt oxides being of particular interest [21,22]. Indeed, it was found that the addition of cobalt to a Pt/Ba/Al catalyst led to high NO oxidation activity, accelerated nitrite/nitrate formation on Ba sites, and gave rise to higher NO x storage capacity in comparison to cobalt-free counterparts [23][24][25][26][27][28].…”

PtM/Ba/Al2O3Ce0.6Zr0.4O2: Influence of Synergetic Interactions between Transition Metal and Platinum on NOx Storage and Reduction

“…For example, the reduction temperatures of PtMn/Ba/ACZ and PtCo/Ba/ACZ are lowered to 655 and 635 °C, respectively, whereas the reduction peak of PtFe/Ba/ACZ that appears at 540 °C may be mainly related to the reduction of surface sulfates, a slightly lower temperature than that in sulfated PtFe/Ba/Al 2 O 3 (550 °C) 9a. It should be mentioned that PtCo/Ba/ACZ possesses another desorption peak at 371 °C, which can probably be ascribed to the reduction of Co species 7a. By combining TPR with XPS, it is found that Fe and Co addition clearly promotes the regeneration ability of sulfated samples.…”

“…It is known that both metallic Pt and platinum oxide are the active components in catalysts, but metallic Pt is more active than platinum oxide 4d. 20 As shown in Figure 2 a, the white‐line intensities in Pt/Ba/ACZ and PtM/Ba/ACZ are higher than that of Pt foil and lower than that of PtO 2 , which suggests that there is positive‐charge Pt in PtM/Ba/ACZ and Pt/Ba/ACZ, and metallic Pt is the main existing state 7a. The radial structural functions (RSFs) for Pt/Ba/ACZ and PtM/Ba/ACZ are displayed in Figure 2 b.…”

Non-thermal plasma-assisted NO storage and reduction over cobalt-containing LNT catalysts

“…Using this approach, high NO x conversions were achieved over the LaMn 0.9 Fe 0.1 O 3 catalyst [4]. Aside from perovskites, a number of simple transition metal oxides with strong oxidation ability and low expense have attracted attention for LNT applications, especially cobalt oxides [5,6]. Wang et al [7] found that the addition of cobalt led to high NO oxidation activity for a Pt/Ba/Al catalyst, and accelerated nitrite/nitrate formation on Ba sites.…”