Electrospun ceria-based nanofibers for the facile assessment of catalyst morphological stability under harsh HCl oxidation reaction conditions

• Published in: Catalysis today 2015-09, Vol.253, p.207-218
• Main Authors: Möller, Maren, Over, Herbert, Smarsly, Bernd, Tarabanko, Nikolay, Urban, Sven
• Format: Article
• Language: English
• Subjects: Deacon process; Electrospinning; HCl oxidation; Mixed cerium and zirconium dioxide; Model catalysis
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2015.02.027

•Electrospinning of mixed Ce+Zr oxide nanofibers.•Stability versus activity of mixed Ce+Zr oxide nanofibers in the Deacon process.•Chlorination of CeO2 during start up and shut down of the reactor.•Stability and activity of nanoparticle-based CeO2 nanofibers. Long-term stability is a major issue in the development of new catalysts and in the improvement of existing catalysts. In general, high-surface-area materials in catalysis are not well suited as model materials for testing catalyst stability, because changes in the morphology are difficult to recognize with electron microscopy. Therefore, we developed a new type of model catalyst in the form of nanofibers for assessing structural changes of CeO2-based catalysts under highly corrosive Deacon reaction conditions. In the Deacon process, chlorine is recycled by heterogeneously catalyzed gas-phase oxidation of HCl, using metal oxide catalysts. The Deacon process generally suffers from degradation of the catalyst due to in-depth chlorination. One-dimensional CeO2-based nanofibers with a well-defined morphology and surface enable direct visualization of structural changes before and after the Deacon reaction, simply employing scanning electron microscopy supported by X-ray diffraction and physisorption measurements. Preparing solid solutions of CeO2 and ZrO2 has shown to improve both the chemical stability and the activity of the catalyst.