Sulfated CexZr1−xO2 oxides. Surface properties and performance for methane oxidation under fuel-rich conditions
Two series of sulfated zirconia-ceria based catalysts have been prepared by coprecipitation of the Zr and Ce salts, which were then sulfated by impregnation using HSO and [(NH)SO] and calcined at 650 °C for 4 h. The sulfated and persulfated Zr-Ce-O samples were synthesized with Zr/Ce ratios ranging...
| Authors: | , , , , , , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2017 |
| Country: | España |
| Institution: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repository: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::b6d1eec7fa8530f318e6e6b4b52c6ec2 |
| Online Access: | http://hdl.handle.net/10261/202755 |
| Access Level: | Open access |
| Keyword: | Ceria-zirconia mixed oxides Acidity Surface characterization Partial oxidation of methane |
| Summary: | Two series of sulfated zirconia-ceria based catalysts have been prepared by coprecipitation of the Zr and Ce salts, which were then sulfated by impregnation using HSO and [(NH)SO] and calcined at 650 °C for 4 h. The sulfated and persulfated Zr-Ce-O samples were synthesized with Zr/Ce ratios ranging from 1 to 15. The textural, structural and surface characteristics of the resulting modified catalysts were determined by N adsorption-desorption, XRD, XPS spectroscopy and TPD of NH, and results were related to their catalytic behaviour. The catalysts were tested in the direct conversion of methane at high temperature (650 °C) under fuel-rich conditions to obtain C oxygenates (CHOH and HCHO). Experiments were conducted using low O/CH ratio mixtures and high space velocity. It was shown that O/CH feeds resulted in practically total combustion of CH when sulfated/persulfated ceria-zirconia catalysts are used, while the nature of the different phases modifies the surface acidity, which plays a crucial role on the extent of deep oxidation reactions. |
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