NOx Storage on BaTi<sub>0.8</sub>Cu<sub>0.2</sub>O<sub>3</sub> Perovskite Catalysts: Addressing a Feasible Mechanism
Vicente Albaladejo-Fuentes,
María-Salvadora Sánchez-Adsuar,
James A. Anderson,
María-José Illán-Gómez
Affiliations
Vicente Albaladejo-Fuentes
Carbon Materials and Environment Research Group, Department of Inorganic Chemistry, Faculty of Science, Universidad de Alicante San Vicente del Raspeig, 03690 Alicante, Spain
María-Salvadora Sánchez-Adsuar
Carbon Materials and Environment Research Group, Department of Inorganic Chemistry, Faculty of Science, Universidad de Alicante San Vicente del Raspeig, 03690 Alicante, Spain
James A. Anderson
Surface Chemistry and Catalysis Group, School of Engineering, University of Aberdeen, Aberdeen AB24 3UE, UK
María-José Illán-Gómez
Carbon Materials and Environment Research Group, Department of Inorganic Chemistry, Faculty of Science, Universidad de Alicante San Vicente del Raspeig, 03690 Alicante, Spain
The NOx storage mechanism on BaTi0.8Cu0.2O3 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 BaTi0.8Cu0.2O3 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, the catalyst activity for NO oxidation promotes NO2 generation and the nitrate formation.
