NOx Storage on BaTi0.8Cu0.2O3 Perovskite Catalysts: Addressing a Feasible Mechanism

Vicente Albaladejo-Fuentes; María-Salvadora Sánchez-Adsuar; James A Anderson; María-José Illán-Gómez

doi:10.3390/nano11082133

NOx Storage on BaTi_0.8Cu_0.2O₃ Perovskite Catalysts: Addressing a Feasible Mechanism

Nanomaterials (Basel). 2021 Aug 21;11(8):2133. doi: 10.3390/nano11082133.

Authors

Vicente Albaladejo-Fuentes¹, María-Salvadora Sánchez-Adsuar¹, James A Anderson², María-José Illán-Gómez¹

Affiliations

¹ Carbon Materials and Environment Research Group, Department of Inorganic Chemistry, Faculty of Science, Universidad de Alicante San Vicente del Raspeig, 03690 Alicante, Spain.
² Surface Chemistry and Catalysis Group, School of Engineering, University of Aberdeen, Aberdeen AB24 3UE, UK.

Abstract

The NOx storage mechanism on BaTi_0.8Cu_0.2O₃ catalyst were studied using different techniques. The results obtained by XRD, ATR, TGA and XPS under NOx storage-regeneration conditions revealed that BaO generated on the catalyst by decomposition of Ba₂TiO₄ plays a key role in the NOx storage process. In situ DRIFTS experiments under NO/O₂ and NO/N₂ show that nitrites and nitrates are formed on the perovskite during the NOx storage process. Thus, it seems that, as for model NSR catalysts, the NOx storage on BaTi_0.8Cu_0.2O₃ catalyst takes place by both "nitrite" and "nitrate" routes, with the main pathway being highly dependent on the temperature and the time on stream: (i) at T < 350 °C, NO adsorption leads to nitrites formation on the catalyst and (ii) at T > 350 °C, the catalyst activity for NO oxidation promotes NO₂ generation and the nitrate formation.

Keywords: NOx storage mechanism; barium-titanium perovskite; in situ DRIFTS; nitrates; nitrites.

Abstract

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