1

Bulk CeO2 has been recently reported as a promising catalyst for the oxidation of HCl to Cl2. In order to undertake the scale up of this system, various oxides (TiO2, Al2O3, and low- and high-surface area ZrO2) have been evaluated as carriers. Supported CeO2 catalysts (3-20 wt. % Ce) prepared by dry impregnation were isothermally tested at the lab scale. Their performance was ranked as: CeO2/ZrO2>> CeO2/Al2O3 ≥ CeO2/TiO2. Kinetic data revealed a lower activation energy and a similar activity dependence on the partial pressure of O2 for CeO2/ZrO2 compared to bulk CeO2. Pilot-scale testing over 3-mm pellets of this catalyst evidenced outstanding stability up to 700 h on stream. In-depth characterization of the carriers and fresh catalysts by N2 sorption, Hg porosimetry, X-ray diffraction, temperature-programmed reduction with H2, Raman spectroscopy, electron microscopy, and in situ prompt gamma activation analysis, enabled to rationalize the different catalytic behavior of the materials. ZrO2 stabilizes nanostructures of CeO2 and a Ce-Zr mixed oxide phase, which offer high dispersion and improved oxidation properties. The catalyst also shows reduced chlorine uptake, and overall stands as a better Deacon material compared to bulk CeO2. CeO2 is present on Al2O3 predominantly as well