Carbon dioxide gasification of carbon black: Isotope study of carbonate catalysis

• Published in: Journal of catalysis Vol. 90; no. 1; pp. 65 - 74
• Main Authors: Saber, John M., Falconer, John L., Brown, Lee F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.01.1984; Elsevier
• Subjects: Catalysis; Catalysts: preparations and properties; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; General. Nomenclature, chemical documentation, computer chemistry; Theory of reactions, general kinetics; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Gasification; Potassium Carbonates; Catalysis; Carbon
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/0021-9517(84)90085-X

Temperature-programmed reaction was used with labeled isotopes ( 13C and 18O) to study interactions between carbon black and potassium carbonate in pure He and 10% CO 2/90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 and 950 K, and in the presence of gaseous CO 2, the complexes participated in C and O exchange with the gas phase while oxygen atoms within the complexes also exchanged wtih those on the carbon surface. As the temperature rose, the complexes decomposed, with CO 2 the initial product. Decomposition started around 500 K in pure He, and around 950 K in CO 2 He . Catalytic gasification began only after decomposition of significant portions of the complexes. Elemental potassium formed, and the active catalyst appears to alternate between being potassium metal and a potassium-oxygen-carbon complex. Potassium carbonate is not part of the catalytic cycle.