EFFECTS OF THE PREPARATION PROCEDURE AND ADDITIVES ON SURFACE TEXTUREOF NICKEL AND COBALT OXIDES AS FINAL DECOMPOSITION PRODUCTS OF NICKELAND COBALT OXYSALTS

The effects of preparation procedure and readily decomposable salt add itives, namely (NH2)(2)CO and NH4NO3, on the texture of NiO and Co3O4 produced by calcination of Ni(NO3)(2) . 6H(2)O and Co(NO3)(2) . 6H(2)O were investigated. Textural characteristics were assessed via analysi s of nitrogen adsorption isotherms, using a number of widely-accepted methods. The thermal genesis courses of NiO and Co3O4, from additive-c ontaining and additive-free oxide precursors were explored using therm ogravimetry, differential thermal analysis and X-ray diffractometry (X RD). The results of surface texture and XRD analyses were largely in a greement and showed that pores are modified. An impregnation procedure using salt additives to NiO and Co3O4 resulted in a marked increase o f surface area (from 23 to 65 m(2) g(-1) for NiO and from 18 to 82 m(2 ) g(-1) for Co3O4). This increase is most likely due to the evolved ga ses and the consequent fragmentation of particles and the widening of pores.