Understanding the catalytic ozonation process on ceria nanorods: Efficacy, Frenkel-type oxygen vacancy as a key descriptor and mechanism insight

Abstract

This work investigated property-activity correlations of ceria (CeO2) in heterogeneous catalytic ozonation (HCO) and explored the key descriptor from various properties. CeO2 nanorods (NRs) calcined at 300–700 °C were adopted in HCO for degrading three organic pollutants. With their physicochemical properties characterized and their HCO performances analyzed in detail, the correlations between different properties and the rates of O3 decomposition, pollutant degradation and total organic carbon (TOC) removal were revealed. Fast pollutant degradation, high TOC removal, good stability and wide pH applicability were achieved. Linear relationships between the rates of O3 decomposition/TOC removal and the density of Frenkel-type oxygen vacancy (OV) were established. Theoretical and spectroscopic studies revealed OV could boost O3 decomposition to generate reactive oxygen species (ROS). The mechanism for ROS generation and pollutant degradation was proposed. This study would contribute to designing efficient catalysts and understanding their performances in HCO for abatement of organic pollutants in wastewaters.