The surface behaviour and catalytic properties of Nd2-XSrXCoO4±Λ mixed oxides

Abstract

The mixed oxides, Nd_2-XSr_XCoO_4±λ (0.4 ≤ x ≤ 1.2), (λ = non-stochiometric oxygen) with the K₂NiF₄ structure were prepared by the polyglycol gel method and used as catalysts for NO reduction. The samples were investigated by IR, TPD, TPR, and XRD methods and iodometry and the effects of the coefficient x on the structure and catalytic activity of the samples were studied. The results show that the Nd_2-XSr_XCoO_4±λ mixed oxides have the K₂NiF₄ structure; other phases are found when x < 0.4 and > 1.2. The amount of Co³⁺ and the lattice oxygen in Nd_2-XSr_XCoO_4±λ increase with increasing x. The catalytic activity of Nd_2-XSr_XCoO_4±λ for NO reduction is closely correlated with the concentration of oxygen vacancies and the amount of Co³⁺.

KEY WORDS: A₂BO₄, Co-containing mixed oxide, NO reduction, Rare-earth
Bull. Chem. Soc. Ethiop. 2006, 20(2), 201-206.