Abstract
The extent to which HCN is produced as a significant product during isobutane-SCR over Fe-MFI catalysts has been investigated together with its origin and further conversion. Catalysts made by both vapor-phase sublimation and solid-state ion exchange can produce well over 100-ppm HCN, which is a major intermediate for N2 production, but the peak concentration is less with the former material due to a higher oxidation activity. HCN production is confined to temperatures giving partial conversion of isobutane, when deposited material suppresses the very high intrinsic activity of Fe-MFI for the further conversion of HCN to N2, largely via hydrolysis to ammonia and NH3-SCR. Activity for the oxidation of NO to NO2 is similarly suppressed. This oxidation step is likely to be the rate determining one in isobutane-SCR rather than the activation of the alkane since there is no deuterium kinetic isotope effect. Decomposition of isobutyronitrile, formed by dehydration of a primary nitroso species via its oxime tautomer, is a possible source of HCN. This decomposition gives propene as a coproduct, which reacts completely during isobutane-SCR and may also be a source of deposits through oligomerization. Secondary and tertiary nitroso intermediates cannot react in this way and, based on the reactions of nitroanalogues, are more likely to undergo elimination to form alkenes. The overall effect is to convert alkane-SCR to SCR with alkenes containing the same number or one less carbon atom.
Similar content being viewed by others
References
C. Yokoyama and M. Misono, Catal. Today 22 (1994) 59.
C. Yokoyama and M. Misono, J. Catal. 150 (1994) 9.
H. Yasuda, T. Miyamoto and M. Misono, ACS Symp. Ser. 587 (1995) 110.
T. Beutel, B. Adelman and W. M. H. Sachtler, Catal. Lett. 37 (1996) 125.
B. J. Adelman, T. Beutel, G. D. Lei and W. M. H. Sachtler, Appl. Catal., B 11 (1996) L1.
J. Wu and S. C. Larsen, J. Catal. 182 (1999) 244.
E. V. Rebrov, A. V. Simakov, N. N. Sazonova and E. S. Stoyanov, Catal. Lett. 58 (1999) 107.
E. V. Rebrov, A. V. Simakov, N. N. Sazonova and E. S. Stoyanov, Catal. Lett. 64 (2000) 129.
F. Poignant, J. L. Freysz, M. Daturi and J. Saussey, Catal. Today 70 (2001) 197.
H.-Y. Chen, T. Voskoboinikov and W. M. H. Sachtler, J. Catal. 180 (1998) 171.
H.-Y. Chen, T. Voskoboinikov and W. M. H. Sachtler, Catal. Today 54 (1999) 483.
C. A. Jones and S. C. Larsen, Catal. Lett. 78 (2002) 243.
N. W. Cant, A. D. Cowan, A. Doughty, B. S. Haynes and P. F. Nelson, Catal. Lett. 46 (1997) 207.
A. D. Cowan, N. W. Cant, B. H. Haynes and P. F. Nelson, J. Catal. 176 (1998) 329.
I. O. Y. Liu, N. W. Cant, B. S. Haynes and P. F. Nelson, J. Catal. 203 (2001) 487.
H.-Y. Chen, T. Voskoboinikov and W. M. H. Sachtler, J. Catal. 186 (1999) 91.
T. Nanba, A. Obuchi, Y. Suguira, C. Kouno, J. Uchisawa and S. Kushiyama, J. Catal. 211 (2002) 53.
F. Poignant, J. Saussey, J.-C. Lavalley and G. Mabilon, Catal. Today 29 (1996) 93.
T. Gerlach, F.-W. Schutze and M. Baerns, J. Catal. 185 (1999) 131.
T. Gerlach, U. Illgen, M. Bartoszek and M. Baerns, Appl. Catal., B 22 (1999) 269.
T. Gerlach and M. Baerns, Chem. Eng. Sci. 54 (1999) 4379.
K.-I. Shimizu, F. Okada, Y. Nakamura, A. Satsuma and T. Hattori, J. Catal. 195 (2000) 151.
A.-Z. Ma and W. Grunert, J. Chem. Soc., Chem. Commun. (1999) 71.
R. Q. Long and R. T. Yang, J. Amer. Chem. Soc. 121 (1999) 5595.
J. A. Sullivan, J. Cunningham, M. A. Morris and K. Keneavey, Appl. Catal., B 7 (1995) 137.
N. W. Hayes, R. W. Joyner and E. S. Shpiro, Appl. Catal., B 8 (1996) 343.
F. Radtke, R. E. Koeppel and A. Baiker, Appl. Catal., A 107 (1994) L125.
F. Radtke, R. A. Koeppel and A. Baiker, Chem. Commun. (1995) 427.
F. Radtke, R. A. Koeppel and A. Baiker, Environ. Sci. Technol. 29 (1995) 2703.
F. Radtke, R. A. Koeppel and A. Baiker, Catal. Today 26 (1995) 159.
I. O. Y. Liu and N. W. Cant, J. Catal. 195 (2000) 352.
C. Gaudin, D. Duprez, G. Mabilon and M. Prigent, J. Catal. 160 (1996) 10.
T. Nanba, A. Obuchi, H. Izumi, Y. Sugiura, J. Xu, J. Uchisawa and S. Kushiyama, Chem. Commun. (2001) 173.
I. O. Y. Liu, N. W. Cant, M. Kogel and T. Turek, Catal. Lett. 63 (1999) 241.
A. Obuchi, C. Wogerbauer, R. A. Koeppel and A. Baiker, Appl. Catal., B 19 (1998) 9.
M. Kogel, V. H. Sandoval, W. Schwieger, A. Tissler and T. Turek, Catal. Lett. 51 (1998) 23.
M. Kogel, R. Monnig, W. Schwieger, A. Tissler and T. Turek, J. Catal. 182 (1999) 470.
H.-Y. Chen and W. M. H. Sachtler, Catal. Today 42 (1998) 73.
H.-Y. Chen and W. M. H. Sachtler, Catal. Lett. 50 (1998) 125.
A. D. Cowan, R. Dumpelmann and N. W. Cant, J. Catal. 151 (1995) 356.
A. D. Cowan and N. W. Cant, Stud. Surf. Sci. Catal 107 (1997) 285.
N. W. Cant and A. D. Cowan, Catal. Today 35 (1997) 89.
K. Hadjiivanov, H. Knozinger, B. Tsyntsarski and L. Dimitrov, Catal. Lett. 62 (1999) 35.
L. J. Lobree, I. C. Hwang, J. A. Reimer and A. T. Bell, Catal. Lett. 63 (1999) 233.
H.-Y. Chen, E.-M. El-Malki, X. Wang, R. A. van Santen and W. M. H. Sachtler, J. Mol. Catal. A 162 (2000) 159.
N. W. Cant, A. D. Cowan, I. O. Y. Liu and A. Satsuma, Catal. Today 54 (1999) 473.
T. Nanba, A. Obuchi, S. Akaratiwa, S. Liu, J. Uchisawa and S. Kushiyama, Chem. Lett. (2000) 986.
R. Q. Long and R. T. Yang, Chem. Commun. (2000) 1651.
R. Q. Long and R. T. Yang, J. Catal. 201 (2001) 145.
A. W. Aylor, L. J. Lobree, J. A. Reimer and A. T. Bell, Stud. Surf. Sci. Catal. 101 (1996) 661.
A. W. Aylor, L. J. Lobree, J. A. Reimer and A. T. Bell, J. Catal. 170 (1997) 390.
A. A. Battison, J. H. Bitter, F. M. F. de Groot, A. R. Overweg, O. Stephan, J. A. van Bokhoven, P. J. Kooyman, C. van der Spek, G. Vanko and D. C. Koningsberger, J. Catal. 213 (2003) 251.
K. D. King and R. D. Goddard, J. Am. Chem. Soc. 97 (1975) 4504.
I. O. Y. Liu and N. W. Cant, to be published
S. van Donk, J. H. Bitter and K. P. de Jong, Appl. Catal., A General 212 (2001) 97.
K. Y. Choo, G. D. Mendenhall, D. M. Golden and S. W. Benson, Int. J. Chem. Kinet. 6 (1974) 813.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liu, I.O.Y., Cant, N.W. The Formation and Reactions of Hydrogen Cyanide During Isobutane-SCR over Fe-MFI Catalysts. Catalysis Surveys from Asia 7, 191–202 (2003). https://doi.org/10.1023/B:CATS.0000008160.18010.cb
Issue Date:
DOI: https://doi.org/10.1023/B:CATS.0000008160.18010.cb