Oxidative coupling of methane over promoted strontium chlorapatite
- 74 Downloads
Strontium zirconium phosphate, unpromoted strontium chlorapatite and strontium hydroxyapatite showed low C2 selectivity for the oxidative coupling of methane, but promoted strontium chlorapatite catalysts showed markedly increased activity and selectivity and also exhibited stable behavior. SrCl2 was the primary promoter and strontium zirconium oxides were considered to be acting as other promoters, but strontium zirconium phosphate and strontium carbonate seemed to be acting adversely. A promoted strontium chlorapatite catalyst which contained a slightly larger amount of SrCl2 than needed to form the chlorapatite showed the best performance and was stable up to 50 h at 1,023 K, and the highest C2+ selectivity and yield were 52% and 13.8%, respectively. Although SrCl2 was more stable than NaCl it decomposed slowly during the reaction, leaving strontium oxide or strontium carbonate behind, which is considered to result in slow deactivation of the catalyst.
Key wordsMethane Oxidative Coupling Strontium Chloride Strontium Chlorapatite Strontium Zirconium Phos-phate
Unable to display preview. Download preview PDF.
- Baeck, S. H., Chung, J. S. and Lee, W. Y, “Oxidative Coupling of Methane over BiOCl-Li2CO3-Sm2O3 Catalyst”HWAHAK KONGHAK,36,429 (1998).Google Scholar
- Chang, J.-S., Park, S.-E. and Lee, Y K., “Characterization of Cobalts-Exchanged Synthetic a-Zirconium Phosphate,”HWAHAKKONGHAK,27, 323 (1989).Google Scholar
- Guo, X.-M., Hidaiat, K. and Ching, C.-B., “An Experimental Study of Oxidative Coupling of Methane in a Solid Oxide Fuel Cell with 1 wt% Sr/La2O3-Bi2O3-Ag-YSZ Membrane”Korean J. Chem. Sng.,15,469 (1998).Google Scholar
- Hutchings, G. J. and Scurrell, M. S., “Methane Conversion by Oxidative Processes: Fundamental and Engineering Aspects,” Wolf, E. E., ed., Van Nostrand Reinhold, New York, 200 (1992).Google Scholar
- Kim, C. S. and Lee, W. Y, “The Reaction Characteristics of Oxidative Coupling of Methane over Ba- and Sr-based Catalysts,”HWAHAKKONGHAK,31, 62 (1993).Google Scholar
- Kim, S.-C, Sunwoo, C.-S. and Yu, E.-Y, “The Effect of Alkali Promoters in Oxidative Coupling of Methane with Mn-Oxide Catalysts,”Korean J. Chem. Eng.,7, 279 (1990).Google Scholar
- Kim, S.-C. and Yu, E.-Y, “The Oxidative Coupling of Methane over Supported Zinc Oxide Catalyst with Alkali Promoters,”HWAHAK KONGHAK,28, 536 (1990).Google Scholar
- Lee, K.-Y, Han, Y.-C, Suh, D. J. and Park, T J., “Pb-substituted Hydroxyapatite Catalysts Prepared by Coprecipitation Method for Oxidative Coupling of Methane,” in “Natural Gas Conversion V,” Parmaliana, A., Sanfilippo, D., Frusteri, F, Vaccari, A. and Arena, F, Eds., Else vier, Studies in Surf. Sci. Catal., 119, 385 (1998).Google Scholar
- Nagamoto, H., Amanuma, K., Nobutomo, H. and Inoue, H., “Methane Oxidation over Perovskite-type Oxide Containing Alkaline-earth Metal,”Chem, Lett., 237 (1988).Google Scholar
- Segawa, K., Kurusu, Y. and Kinoshita, M., “Catalysis by Acids and Bases,”Imelik, B., ed., Elsevier, Amsterdam, B.V., 83 (1985a).Google Scholar
- Yang, W. M., Yan, Q. J. and Fu, X. C, “A Comparative Study of Catalytic Behaviours of Sr-Ti, Sr-Zr, Sr-Sn Perovskites and Corresponding Layered Perovskites for the Oxidative Coupling of Methane,” in “Methane and Alkane Conversion Chemistry” Bhasin, M. M. and Slocum, D. W., Eds., Plenum, New York, 71 (1995).Google Scholar