<b>The surface behaviour and catalytic properties of Nd_2-XSr_XCoO_4±Λ mixed oxides</b>

Abstract

ABSTRACT. The mixed oxides, Nd 2-x Sr x CoO 4±• (0.4 • x • 1.2), (λ = non-stochiometric oxygen) with the K 2 NiF 4 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-x Sr x CoO 4±• mixed oxides have the K 2 NiF 4 structure; other phases are found when x < 0.4 and > 1.2. The amount of Co 3+ and the lattice oxygen in Nd 2-x Sr x CoO 4±• increase with increasing x. The catalytic activity of Nd 2-x Sr x CoO 4±• for NO reduction is closely correlated with the concentration of oxygen vacancies and the amount of Co 3+ .