Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.jcat.2004.11.045
Title (Primary) Interaction between sulfated zirconia and alkanes: prerequisites for active sites - formation and stability of reaction intermediates
Author Li, X.B.; Nagaoka, K.; Simon, L.J.; Lercher, J.A.; Wrabetz, S.; Jentoft, F.C.; Breitkopf, C.; Matysik, S.; Papp, H.
Source Titel Journal of Catalysis
Year 2005
Department EXPOEPID
Volume 230
Issue 1
Page From 214
Page To 225
Language englisch
Keywords Sulfated zirconia; Alkanes; Isomerization; Active sites; Reaction intermediates; Transient measurements
Abstract Two sulfated zirconia catalysts were prepared via sulfation and calcination of zirconium hydroxide at 873 K; the zirconium hydroxide had been aged at room temperature for 1 h (SZ-1) or aged at 373 K for 24 h (SZ-2). SZ-1 was active for n-butane isomerization at 373 K; SZ-2 reached a similar performance level only at 473 K. Both materials contained about 9 wt% sulfate and were tetragonal. Because of a lower BET surface area (105 vs. 148 m2/g) SZ-1 featured a higher sulfate density, and XRD and EXAFS analysis showed larger (ca. 10 nm) and more well ordered crystals than for SZ-2. n-Butane TPD on SZ-1 showed a butene desorption peak at low temperature, whereas no obvious butene desorption was observed with SZ-2, suggesting that SZ-1 has a higher oxidizing power at low temperature than SZ-2. The number of sites capable of dehydrogenation are less than 5 μmol/g, because the differential heats of n-butane adsorption as measured by microcalorimetry were 45–60 kJ/mol for higher coverages, indicating weak and reversible interaction. TAP experiments describe the adsorption and desorption behavior of n-butane at different activity states and are the basis for a simple adsorption model. Reactant pulses and purge experiments show that the active species, presumably formed in an oxidative dehydrogenation step, are stable at the surface under reaction conditions.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=3570
Li, X.B., Nagaoka, K., Simon, L.J., Lercher, J.A., Wrabetz, S., Jentoft, F.C., Breitkopf, C., Matysik, S., Papp, H. (2005):
Interaction between sulfated zirconia and alkanes: prerequisites for active sites - formation and stability of reaction intermediates
J. Catal. 230 (1), 214 - 225 10.1016/j.jcat.2004.11.045