Hostname: page-component-77c89778f8-gvh9x Total loading time: 0 Render date: 2024-07-17T12:12:51.007Z Has data issue: false hasContentIssue false

Methanation of CO2 on Ni(II)-Bearing Ferrite (NixFe3-xO4-δ; x=0.39, δ>0) in Flow System

Published online by Cambridge University Press:  15 February 2011

H. Kato
Affiliation:
Department of Chemistry, Research Center for Carbon Recycling & Utilization, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152, JAPAN
M. Tabata
Affiliation:
Department of Chemistry, Research Center for Carbon Recycling & Utilization, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152, JAPAN
M. Tsuji
Affiliation:
Department of Chemistry, Research Center for Carbon Recycling & Utilization, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152, JAPAN
Y. Tamaura
Affiliation:
Department of Chemistry, Research Center for Carbon Recycling & Utilization, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152, JAPAN
Get access

Abstract

The methanation of CO2 has been studied by using reduced Ni(II)-bearing ferrite (NixFe3-xO4-δ; x=0.39, δ=0.1∼0.2) in an H2/CO2 mixed gas flow system. A yield of 31% and a high selectivity of 89% were obtained in the methanation for 6h using the H2-reduced Ni(II)-bearing ferrite. The X-ray diffractometry showed that the reduced Ni(II)-bearing ferrite during the methanation retained the spinel-type structure whose lattice constant increased from 0.8375 to 0.8379 nm. The chemical analysis corroborated an increase in the mole ratio of Fe2+/Fetotal in the Ni(II)-bearing ferrite. These results suggest that oxygen-deficient sites were formed in the spinel structure of the reduced Ni(II)-bearing ferrite. It has been found from the analysis using the Langmuir isotherm for dissociative adsorption that CO2 is adsorbed onto oxygen-deficient sites to be decomposed to an elemental carbon and two oxygen-deficient ions. The methanation of CO2 is considered to proceed owing to the oxygen deficient sites. It is considered that the methanation consists of three elementary reaction steps: 1) Formation of oxygen-deficient sites by H2-reduction, 2) Reduction of CO2 to carbon and Incorporation of two oxygen ions of the CO2 into the oxygen-deficient sites, and 3) Hydrogenation of the deposited carbon to CH4.

Type
Research Article
Copyright
Copyright © Materials Research Society 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Weatherbee, G. D. and Bartholomew, C. H., J. Catal. 68, 67 (1981).Google Scholar
2. Weatherbee, G. D. and Bartholomew, C. H., J. Catal. 87, 352 (1984).Google Scholar
3. Tamaura, Y. and Nishizawa, K., Energy Convers. Mgmt. 33, 573 (1992).Google Scholar
4. Nishizawa, K., Kato, H., Mimori, K., Yoshida, T., Hasegawa, N., Tsuji, M. and Tamaura, Y., J. Mater. Sci. 29, 768 (1994).Google Scholar
5. Kodama, T., Kato, H., Tsuji, M., Tamaura, Y. and Chang, S. G., in Proceedings of World Congress III on Engineering and Environment, Beijing, Oct. 12–14, 1993, edited by Yi, Qian, Jiming, Hao and Jun, Long (International Academic Publishers, Beijing, 1993), Vol.2, pp. 518–523.Google Scholar
6. Tamaura, Y. and Tabata, M., Nature 346, 255 (1990).Google Scholar
7. Nishizawa, K., Kodama, T., Tabata, M., Tsuji, M. and Tamaura, Y., J. Chem. Soc. Faraday Trans. 88, 2771 (1992).Google Scholar
8. Kaneko, K. and Katsura, T., Bull. Chem. Soc. Jpn. 52, 747 (1979).Google Scholar
9. Waldron, R. D., Phys. Rev. 99, 1727 (1955).Google Scholar
10. Volenik, K., Seberini, M. and Neid, J., Czech. J. Phys. B 25, 1063 (1975).Google Scholar
11. Fujita, S., Usui, M. and Takezawa, N., J. Catal. 134, 220 (1992).Google Scholar
12. Kröger, F. A. and Vink, H., in Solid state Phys., edited by Seitz, F. and Turnbull, D. (Academic Press, New York, 1956), Vol.3, pp. 307435.Google Scholar