| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 41058 | Applied Catalysis A: General | 2011 | 8 Pages |
Effects of dopant on direct decomposition of nitric oxide (NO) over Ba3Y4O9 were investigated and it was found that Sc is partially substituted Ba3Y3.4Sc0.6O9 catalyst shows a high NO decomposition activity (N2 yield: 92%) at 1123 K among the examined dopants. Sc is considered to contribute to the stabilization of the Ba3Y4O9 crystal phase and also form the intrinsic oxygen defects. This catalyst was active in NO decomposition in the presence of O2 and maintained its high activity at high space velocity values. Fourier transform infrared spectroscopy (FT-IR) measurement suggests that initial adsorption state of NO is a bent-type NO−. Moreover, the rate-determining step for NO decomposition seems to be the coupling of the NO species adsorbed on the surface. Doping with Sc effectively weakened the adsorption of NO species, resulting in the increased reactivity. FT-IR and temporal analysis of products (TAP) measurements suggested that N2O may be an intermediate species in NO decomposition.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (149 K)Download as PowerPoint slideHighlights► Ba3Y4O9, which has an oxygen-deficient layered structure is stabilized by Sc doping. ► Ba3Y3.4Sc0.6O9 showed highest NO decomposition activity at 1123 K. ► NO conversion to N2 attained values of 92% in spite of its low surface area. ► TAP analysis suggests that the direct decomposition of NO proceeded via N2O.
