PVP modulation of CeCoOx morphology to enhance chlorine resistance and o-dichlorobenzene degradation

To address the problems of difficult degradation of Chlorinated volatile organic compounds (CVOCs) and easy deactivation of catalysts by chlorine poisoning, o-Dichlorobenzene ( o- DCB) was used as a model pollutant, and a shape size-tunable CeCoOx catalyst was designed by Prussian blue analogue (PBA) derivatization, and the nucleation rate of the precursor was controlled by regulating the amount of Polyvinyl pyrrolidone (PVP) added (0–15 g), so that the CC-PVP y catalysts with hexagonal bipyramidal to lamellar gradient structures were successfully prepared, and their structure-efficacy relationship and mechanism were systematically elucidated. The results showed that the appropriate amount of PVP could optimize the crystallinity and size uniformity of the precursor, and the resulting CC-PVP 1 catalyst showed a complete hexagonal bipyramidal structure with maximum specific surface area and pore volume, and the surface was enriched with highly active Co 3+ species and adsorbed oxygen. Mechanistic studies have shown that chlorine poisoning mainly occurs through Cl - occupying the oxygen vacancies, leading to a decrease in the crystallinity of the catalyst, a collapse of the pore structure, a weakening of the redox capacity and a decrease in the number of acid sites. CC-PVP 1 significantly delayed the deactivation by reducing the amount of Cl deposited on the catalyst surface due to its high structural integrity. This study deepens the understanding of the catalytic combustion mechanism of CVOCs and provides a feasible strategy for the development of efficient chlorine-resistant catalysts.