Direct NO decomposition over La2−xBaxNiO4 catalysts containing BaCO3 phase
La2−xBaxNiO4 (x ≤ 1.2) catalysts have been prepared by citrate method. XRD patterns and IR spectra indicate that with the doping of Ba, more BaCO3 appears and perovskite-like structure is seriously distorted. In directly decomposing 4% NO, the highest N2 yield is achieved with La1.2Ba0.8NiO4 composed of perovskite-like structure phase and BaCO3 in the absence/presence of oxygen. The results of iodometry and H2-TPR reveal that the increase in Ba causes the increase in Ni3+ content. O2-TPD and NO adsorption tests confirm that Ba doping resulted in the increase in oxygen vacancy (Vo). Thus, the redox capability and the amount of Vo are enhanced. It is suggested that the BaCO3 phase, NOx storage component, contributes to the increase in activity by NO-TPD, NO2-TPD and in situ DRIFT. Thus, BaCO3 plays an important role in quickening up the run of catalytic NO decomposition recycle.
Journal: Applied Catalysis B: Environmental - Volume 82, Issues 3–4, 8 August 2008, Pages 255–263