Role of the lattice-energy from chemical agents in the activation of highly-condensed carbons

Abstract

Highly condensed carbons from pet-coke were first treated with Na/K hydroxides and carbonates and then with H2SO4. The esterification reaction of palmitic acid reached conversions of up to 97 % on the yielded activated carbons. The results evidence the relationship between the efficacy of Na/K hydroxides and carbonates as treatment agents and their lattice potential energy. Moreover, the analysis of carbonaceous solids confirms that both surface area and acidity are primary factors promoting activity in the esterification reaction. Furthermore, the results do not indicate a direct relationship between the activity and the oxidized species (SOx) arising from the treatment with H2SO4. The relatively low melting and decomposition temperature of Na/K hydroxides can improve their effect on the pet-coke matrix, leading to higher surface areas, acidities, and catalytic activities than treatment with carbonates. This supports an affinity between the carboxyl functions of the fatty acid molecules and the polar and catalytically active centers of the hydroxide-treated solid surface.