Understanding the reactions of CO2, NO and N2O with activated carbon catalysed by binary mixtures

Abstract

The carbon bulk diffusion mechanism and the catalytic carbon "nanoworm" model are used to understand the role of the phases prevailing in the catalyst particles and the causes of the synergistic effects observed in gasification rates of activated carbon by CO2, NO, and N2O. The kinetics were isothermally studied with the help of a TGA apparatus. Single and binary catalysts were used. The metals were deposited on carbon by incipient wetness. Synergistic effects were observed with some binary systems. Carbon gasification by CO2 and NO were particularly promoted by the addition of Ba combined with V, and gasification by N2O was promoted by Mn combined with Ba. The changes of catalyst phases with temperature were observed by in situ X-ray diffraction. Temperature-programmed experiments using NO showed N2, N2O, CO2, and CO as reaction products, while experiments using N2O showed only CO2 and N2. With CO2, only CO formation was detected.