Poisoning mechanism of the coexistence K and SO2 on the deNOx of MnO2/TiO2 catalyst at low temperature

Manganese-based catalysts supported by TiO2 (MnO2/TiO2) show good deNOx performance at low temperature. However, the microscopic impact mechanism of poisonous substances such as K and SO2 on the deNOx of the MnO2/TiO2 catalyst is a grey area. In this work, the poisoning mechanism of K and SO2 coexistence on the deNOx of the MnO2/TiO2 catalyst was explored by using a density functional theory combined with experimental methods. SO2 has low adsorption performance on the MnO2/TiO2 (001) surface, while it can be oxidized to form SO3, and it will react with the catalyst to form sulfates. K poisoning makes NH3 and NO molecules more difficult to be adsorbed on the MnO2/TiO2 (001) surface. However, when SO2 is introduced on the catalyst surface with K poisoning, it can interact with K and change the charge transfer from K to the catalyst surface, alleviating the K poisoning of the catalyst. These results contribute to the understanding of the mechanism of K and SO2 co-poisoning on the deNOx of Mn-based catalysts at a microscopic level, and provide guidance for designing Mn-based catalysts with high anti-poisoning ability.

Automated summary

The study explored the poisoning mechanism of K and SO2 coexistence on the deNOx performance of MnO2/TiO2 catalyst using density functional theory combined with experimental methods. It was found that SO2 had low adsorption performance but could be oxidized to form SO3 and react with the catalyst to form sulfates. K poisoning hindered the adsorption of NH3 and NO molecules on the catalyst surface, but the introduction of SO2 alleviated the K poisoning by interacting with K and changing the charge transfer. These findings provide insights into the mechanism and design of Mn-based catalysts with high anti-poisoning ability.