A chromatographic effect observed during deposition of Cu-Mn precursors onactive carbon

The possibility of appearance of a chromatographic effect during the deposi tion of Cu-Mn precursors on active carbon with a view to obtaining supporte d oxide catalysts with a definite active phase composition has been investi gated. By impregnation of the support with aqueous solutions of copper and manganese nitrates and subsequent drying at 110 degrees C, two types of sam ples have been obtained: one-component and two-component ones. They have be en characterized by chemical analysis, IR spectroscopy, EPR analysis, and m agnetic and adsorption measurements. It has been established that during th e preparation of two-component precursors the chromatographic effect is not very strong. Due to the complex chemical nature of the active carbon surfa ce, the copper and manganese ions are adsorbed at different sites. On the b asis of the isoelectric point of the active carbon and the pH value of the impregnating solutions, a scheme for the occurrence of adsorption processes has been proposed. The porous texture of the active carbon permits deposit ion of the precursor at definite surface sites; due to this it is very prom ising as a support of two component oxide catalysts, (C) 2000 Academic Pres s.