A COMPARATIVE-STUDY OF LACOO3 PREPARED BY VARIOUS WET CHEMICAL METHODS

A comparative study of four different methods of preparation of LaCoO3 by precipitation as oxalates, carbonates, citrates and hydroxides of La and. Co followed by calcination at different temperatures to form L aCoO3 is presented. The extent of formation of the LaCoO3 phase from t he precursors as a function of temperature is systematically followed using XRD, TG-DTA, and FT-IR techniques. Higher surface area (20 m(2)/ g) samples of LaCoO3 with no oxide impurities and with smaller particl e size are formed from the citrate complex and the mixed hydroxides on calcination at 873 K. These are found to be more active in the oxidat ion of C-2-C-4 hydrocarbons at 573 K than the samples prepared from ot her mixed precipitates or by the ceramic route.