Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-25T15:12:31.470Z Has data issue: false hasContentIssue false
  • English
  • Français

Activation of Alkanes by Transition Metal Nitrides and Carbides

Published online by Cambridge University Press:  15 February 2011

C. A. Bennett ,
M. K. Neylon ,
H. H. Kwon ,
S. Choi ,
K. E. Curry  and
L. T. Thompson
C. A. Bennett
Affiliation:
Department of Chemical Engineering, University of Michigan, Ann Arbor, M1 48109
M. K. Neylon
Affiliation:
Department of Chemical Engineering, University of Michigan, Ann Arbor, M1 48109
H. H. Kwon
Affiliation:
Present Address: Department of Chemistry, Lehigh University, Bethlehem, PA 18015
S. Choi
Affiliation:
Present Address: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
K. E. Curry
Affiliation:
Union Carbide Corporation, South Charleston, WV 25303
L. T. Thompson
Affiliation:
Department of Chemical Engineering, University of Michigan, Ann Arbor, M1 48109
Get access

Abstract

Group V and VI nitrides and carbides were synthesized by the temperature programmed reaction of metal oxides with ammonia or an equimolar mixture of methane/hydrogen. The synthesis protocols were developed using thermogravimetric techniques. The resulting nitrides and carbides were primarily mesoporous and possessed surface areas in the range of 11 – 81 m2/g. Their alkane activation rates were comparable to a Pt-Sn/AL20 3 dehydrogenation catalyst and the surface area normalized reaction rates decreased in the following order: Mo2N > W2C > WC > W2N > WC1−x > VCoa0.05N > MO2C > VN = VC > NbMo0.01 N > NbMo0.05 > NbN = NbC. The activities measured at 450°C ranged between 1011 – 1013 molecules/cm2/s for n-butane and 1012 – 1013 molecules/cm2/s for n-hexane. The Group VI nitrides and carbides were far more active than the Group V materials. The Group VI materials catalyzed the hydrogenolysis and dehydrogenation reactions with similar activities whereas the Group V materials were more than 98% selective to dehydrogenation. While the metal atom type had the most significant effect on the catalytic properties, the lattice structure of the material also played a role. In particular, we observed that WC (hex) was almost twice as active as WC1-x (fcc). Nitrides and carbides of the same metal and lattice structure possessed similar catalytic properties, implying that the effect of the non-metal atom type was minimal. The W2N catalyst was found to be highly selective towards n-butane isomerization. The multimetallic nitrides each demonstrated some form of synergy.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 549: Symposium FF – Advanced Catalytic Materials - 1998 , 1998 , 45
Copyright
Copyright © Materials Research Society 1999

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. Choi, S., Ph. D. Dissertation, University of Michigan, 1998.Google Scholar
2. Curry, K. E., Ph. D. Dissertation, The University of Michigan, 1995.Google Scholar
3. Kwon, H. H., Ph. D. Dissertation, University of Michigan, 1998.Google Scholar
4. LeClercq, L., Provost, M., Pastor, H., Grimblot, J., Hardy, A. M., Gengembre, L., and LeClercq, J., J. Catal. 117, 371 (1989).Google Scholar
5. Levy, R. B. and Boudart, M., Science 181, 547 (1973).Google Scholar
6. Neylon, M. K., Choi, S., Kwon, H., Curry, K. E., and Thompson, L. T., Appl. Catal. A, accepted for publication (1998).Google Scholar
7. Sinfelt, J. H. and Yates, D. J. C., Nature Phys. Sci. 229, 27 (1971).Google Scholar
8. Oyama, S. T., J. Catal. 133, 358 (1992).Google Scholar
9. Sajkowski, D. J. and Oyama, S. T., ACS Prep. Div. Petrol. Chem. 35(2), 233 (1990).Google Scholar
10. Schlatter, J. C., Oyama, S. T., Metcalfe, J. E., and Lambert, J. M., Ind. Eng. Chem. Res. 27, (1988).Google Scholar
11. Pierson, H. O., “Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing, and Applications,” Noyes Publications, Westwood, New Jersey, 1996.Google Scholar
12. Ledoux, M. J., Huu, C. P., Guille, J., and Dunlop, H., J. Catal. 134, 383 (1992).Google Scholar
13. Lee, J. S., Oyama, S. T., and Boudart, M., J. Catal. 106, 125 (1987).Google Scholar
14. Volpe, L. and Boudart, M. J., J. Solid State Chem. 59, 332 (1985a).Google Scholar
15. Volpe, L. and Boudart, M. J., J. Solid State Chem. 59, 348 (1985b).Google Scholar
16. Chen, J. G., J. Catal. 154, 80 (1995).Google Scholar
17. Chen, J. G., Chem. Rev. 96, 1477 (1996).Google Scholar
18. Harreld, J. H., Dong, W., and Dunn, B., Mat. Res. Bull. 33, 561 (1998).Google Scholar
19. Guczi, L., Sarkany, A., and Tetenyi, P., Faraday Trans. 70, 1971 (1974).Google Scholar