A comparative study of the roles of KCN and NaCN as catalytic precursors in the Boudouard reaction

The rate of reaction between carbon dioxide and coke with or without added KCN and NaCN was studied using thermogravimetry. The chemical stability of KCN or NaCN during catalysis, the changes in the concentration of potassium or sodium in coke and the pore structure of coke were studied as a function of time. The influences of these variables on the rate of coke-CO₂ reaction were determined. Since the catalysis depends on the catalyst-carbon contact, the distribution of potassium in the coke structure was examined. A porous solid reaction model was used to examine the contributions of chemical reaction and pore diffusion in the overall rate of coke-CO₂ reaction.