Highly Active and Stable TiO2{001}-Supported Palladium Catalyst for CO Oxidation in Complex Atmospheres

Catalytic oxidation has become a crucial technology for removing CO from industrial flue gas. However, the complex composition of flue gas (including NH3, NO, SO2, H2O, etc.) poses significant challenges to the catalytic activity and stability of catalysts. In this work, we propose a new strategy for constructing highly efficient catalysts by loading a Pd component onto TiO2 nanosheets (NSs) with predominantly exposed {001} facets. It has been revealed that the well-connected channels, abundant oxygen vacancies and Ti3+ species on the TiO2(NS) support facilitate the formation of highly dispersed and electron-rich Pd nanoparticles. The weak adsorption of impurities such as NH3, SO2, NO and H2O on these active sites promotes the adsorption and activation of the target reactants (CO and O2), thereby enhancing catalytic activity. Furthermore, such reduced adsorption inhibits the aggregation of Pd nanoparticles and synergizes with the intrinsically weak NH3 adsorption of TiO2(NS) to suppress ammonium sulfate species deposition, thereby enhancing long-term catalytic stability. This work advances TiO2 facet engineering in catalysis and offers new design concepts for efficient CO oxidation catalysts in complex atmospheres.