Catalytic effect of KOH on textural changes of carbon macro-networks by physical activation

The synthesis and definition of the topological organization of polygonal macro-networks of carbon in the form of films have been performed by controlled pyrolysis of saccharose. The pentagon was found to be the most abundant polygon in the film networks, which presented ring areas in the range of 4-12 mm(2). In addition to the bi-dimensional films. irregular sponge balls were also obtained featuring a similar random network structure to that obtained in the films. The sponges developed into a continuous net of tri-dimensional random network in the form of tubes with coiled shapes. The formation of carbon macro-coils was attributed to the presence of potassium particles inside the original carbonaceous matrix. A study of textural changes of the macro-networks of carbon by activation under flow of N-2 and CO2 has shown that it is possible to obtain activated carbons from the macro-networks with BET surface areas as high as 850 and 981 m(2)g(-1) under flow of N-2 and CO2, respectively. From the study of textural changes of the macro-networks of carbon, a detailed mechanism that involves the role of KOH as a catalyst for the activation of the macro-networks has been proposed. (C) 2004 Elsevier B.V. All rights reserved.