STUDIES OF NI-IMPREGNATED ACTIVE CARBON - EFFECT OF THERMAL TREATMENT ON THE TEXTURE OF ACTIVE CARBON AND THE STATE OF THE ACTIVE PHASE

摘要

The modification of active carbon by impregnation with an aqueous solution of Ni(NO3)(2) . 6H(2)O (2% Ni) has been investigated. Four samples are obtained in air at 200, 300, 400, and 550 degrees C, respectively. It is established that heat treatment up to 400 degrees C leads to additional activation of the samples, which is accompanied by an increase of their adsorption characteristics. At these temperatures the changes observed are mainly in the microporous region. Destruction of the texture and decrease in the adsorption characteristics of the samples are observed at 550 degrees C, The active phase has been investigated by different methods such as thermogravimetric analysis (TGA), ESCA, and magnetic measurements. The results obtained indicate formation of mixed phases with different compositions at the different temperatures: Ni(OH)(2)(NO3)(2) . H2O, Ni(OH)(2), and NiO at 200 degrees C, Ni(OH)(2) and NiO at 300 and 400 degrees C, and NiO and Ni at 550 degrees C. (C) 1996 Academic Press, Inc. [References: 30]