JOURNAL of the Tunisian Chemical Society

An infrared spectroscopic study of the adsorption of NO, CO and NO + CO on α-Fe₂O₃ was carried out in order to identify chemisorbed species and discuss adsorption sites. Stable nitrate species are formed on the surface at beam temperature (b.t.) when NO is adsorbed. Depending on the pressure, NO adsorbs at b.t. also to form Fe³⁺ (NO) species. Only a weakly adsorbed species, coordinated with a cationic sites to form different types of carbonates is observed at high temperature adsorption (473 - 523 K). In the presence of NO + CO mixture, stable nitrate ions are formed when temperature is increased from b.t. to 423 K. At higher temperature (473 - 523), NO and CO mainly chemisorb as nitrates and carbonates in to an adsorption of NO on partially reduced cationic sites : Fe^(3-δ)+(NO); Fe²⁺(NO).

H. Batis, N. Harrouch, A. Ghorbel

Pages 51-58