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| ID:
213989.0,
Fritz-Haber-Institut / Inorganic Chemistry |
| Interaction between Sulfated Zirconia and Alkanes: Prerequisites for Active Sites – Formation and Stability of Reaction Intermediates |
| Authors: | Li, Xuebing; Nagaoka, Katsutoshi; Simon, Laurent J.; Lercher, Johannes A.; Wrabetz, Sabine; Jentoft, Friederike C.; Breitkopf, Cornelia; Matysik, Silke; Papp, Helmut | | Language: | English | | Research Context: | Project 1: Acid-base & redox properties of promoted sulfated zirconia | | Date of Publication (YYYY-MM-DD): | 2005 | | Title of Journal: | Journal of Catalysis | | Journal Abbrev.: | J. Catal. | | Volume: | 230 | | Start Page: | 214 | | End Page: | 225 | | Review Status: | Peer-review | | Audience: | Experts Only | | Abstract / Description: | Two sulfated zirconia catalysts were prepared via sulfation and calcination at 873 K of zirconium hydroxide 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 isomerisation at 373 K; SZ-2 reached similar performance only at 473 K. Both materials contained about 9 wt% sulfate and were tetragonal. Due to a BET lower surface area (105 m2/g 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. | | External Publication Status: | published | | Document Type: | Article |
| Communicated by: | Robert Schlögl | | Affiliations: | Fritz-Haber-Institut/Inorganic Chemistry/Functional Characterization
| | External Affiliations: | Technische Universität München, Department of Chemistry,
Lichtenbergstraße 4, 85747 Garching, Germany
Universität Leipzig, Institute of Technical Chemistry, Linnéstr. 3, 04103 Leipzig, Germany
| | Identifiers: | URL:http://www.sciencedirect.com/science?_ob=MImg&_ima... [only for subscriber] | |
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