Research progress on the poisoning mechanism of flue gas VOCs purification catalysts

In the industrial environment, the composition of flue gas is complex, and impurities in flue gas can lead to catalyst poisoning and deactivation, which severely restricts their application in practice. This paper reviews the catalytic oxidation mechanism of VOCs, the poisoning effect of flue gas impurities on VOCs purification catalysts, and the construction of novel anti-poisoning catalysts. Furthermore, methods to alleviate catalyst poisoning are discussed. In terms of the oxidation mechanism, there are three catalytic oxidation models: Marse-van Krevelen, Langmuir-Hinshelwooch, and Eley-Rideal. Regarding the poisoning mechanism of catalysts, water vapor, SO2, sulfur/chlorine-containing VOCs, and their catalytic intermediates in industrial flue gas compete with the target reactants for adsorption sites. This competition occupies or reacts with the active sites of the catalyst, thus reducing its activity and even causing catalyst poisoning and inactivation. To construct anti-poisoning catalysts, the anti-poisoning performance of catalysts was improved by modifying catalyst supports, embellishing catalyst surfaces, introducing protectants/inhibitors, and constructing bimetallic catalysts. Based on the poisoning mechanism of VOCs purification catalysts in flue gas, the discussion and analysis of effective strategies will facilitate developing practical high-performance catalysts, provide theoretical guidance for industrial flue gas treatment, and promote the efficient removal of industrial flue gas.