STRUCTURAL FEATURES AND CATALYTIC PROPERTIES OF AgFeO2 BINARY OXIDE IN THE СО OXIDATION REACTION

Abstract

Abstract: Structural features and catalytic properties of silver and iron binary oxide AgFeO2 in the СО oxidation reaction are investigated. Binary oxide samples are obtained by coprecipitation and hydrothermal synthesis techniques at different temperatures. In the temperature range of 140-180 °С, well crystallized AgFeO2 particles are formed primarily with a 3R polytype structure (~90%), and at T = 60-120 °С highly dispersed particles with a developed defect structure are obtained. It is shown that calculated X-ray diffraction patterns of models of delafossite crystals with microtwinning are well consistent with experimental curves. Binary oxide AgFeO2 samples demonstrate a high activity in the СО oxidation reaction, which increases with a decrease in the synthesis temperature. The highest specific catalytic activity is found for highly dispersed samples with a developed defect structure. During catalytic experiments the effect of the reaction medium modifies the surface composition due to the partial exit of silver from the delafossite structure. [Figure not available: see fulltext.].