NO oxidation performance and kinetics analysis of BaMO (M=Mn, Co) perovskite catalysts.

Perovskite is an efficient and emerging catalyst for NO oxidation. In this study, BaMnO and BaCoO perovskite catalysts were synthesized by the sol-gel method, and their catalytic oxidation performances of NO were studied. The catalytic performances indicated that BaMnO and BaCoO perovskites had the highest NO oxidation activities with the NO conversions of 78.2% at 350 °C and 84.3% at 310 °C, respectively. The high activities of BaMnO and BaCoO perovskite catalysts were related to the abundant surface adsorption oxygen (O = 76.21% and 78.57%, respectively) and the high concentration of Mn (Mn/Mn = 66.95%) and Co (Co/Co = 63.8%). Moreover, the results of FT-IR and kinetics revealed that NO and O adsorbed on the surface of samples and combined with the B-O band to form bidentate nitrate and bridging nitrate, which eventually was converted into NO. The kinetics analysis revealed that the NO oxidation reaction followed the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. In addition, the activation energies were 36.453 kJ/mol for BaMnO and 30.081 kJ/mol for BaCoO, implying that BaMnO and BaCoO provide low-cost and efficient catalysts, which can be comparable to Pt noble metal catalysts.