Support-Rebalanced Cu-Ce-V/γ-Al2O3 Catalysts for Durable Fixed-Bed HCl Oxidation: Redox-Acid-Oxygen Rebalancing for Chlorine Recycling.

Catalytic oxidation of waste HCl to Cl2 enables chlorine recycling, but its practical implementation requires shaped catalysts that combine high productivity with long-term chemical and mechanical stability. Herein, a spherical Cu-Ce-V/γ-Al2O3 catalyst was developed by integrating a redox-active Cu-Ce-V oxide ensemble with mechanically robust γ-Al2O3 pellets for fixed-bed HCl oxidation. At a catalyst-bed temperature of 420 ± 5 °C under an undiluted HCl/O2 feed, the catalyst achieved an HCl conversion of approximately 78.2% and a Cl2 space-time yield of 17.04 mol∙kgact-1∙h-1. Stable fixed-bed operation was maintained for 200 h, accompanied by 98.41% mass retention after ultrasonication, 97.8% Cu retention, and 81.6% surface-area retention. Post-reaction characterization revealed that γ-Al2O3 induces a redox-acid-oxygen rebalancing of the Cu-Ce-V phase, generating a more oxidized and moderately reducible cationic state while retaining oxygen-release capacity and a Lewis-acid-dominated environment for HCl adsorption. In situ DRIFTS further shows that HCl induces the accumulation of hydroxylated and hydrated surface species, whereas O2 co-feeding markedly attenuates these surface descriptors. Therefore, these results suggest that the alumina-supported architecture dynamically moderates HCl-induced surface evolution and suppresses irreversible structural degradation. This work provides a thermodynamically consistent strategy for translating Cu-Ce-V redox chemistry into a durable shaped catalyst for fixed-bed HCl-to-Cl2 recycling.