Improving the catalytic performance of ozone decomposition over Pd-Ce-OMS-2 catalysts under harsh conditions

Abstract

Durable Pd-Ce-OMS-2 catalysts for ozone catalytic decomposition under harsh conditions were successfully prepared via a simple one-step hydrothermal process. The incorporation of Pd could greatly improve the ozone removal performance of the catalysts under high GHSV and RH conditions. The catalysts were evaluated by XRD, ICP-OES, BET, XRF, Raman, TEM, FE-SEM, XAFS, XPS, H₂-TPR and O₂-TPD. The enhancement effect of Pd is discussed in terms of the relationship between the activity and structure. The inhibiting effect of oxidized palladium on the crystal growth of these catalysts leads to a decrease in the grain size and crystallinity, increasing the proportion of amorphous regions, and thus significantly increases the specific surface area, lattice defects and low-valence manganese content of Ce-OMS-2. The interaction between Pd and Mn enhances the lability of oxygen on the catalyst surface and accelerates the redox reaction. The increase in oxygen vacancy concentration caused by Pd–Mn interactions is the key factor in improving the catalytic ozone decomposition performance of manganese oxide.