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

• 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.

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