Effect of the Type of Active Component–Support Interaction on the Low-Temperature Activity of Metal–Oxide Catalysts in CO Oxidation

The Pt–SnO_x, Pd–SnO_x, and Au–SnO_x composite catalysts were synthesized by pulsed laser ablation. The catalyst testing in the CO + O₂ reaction showed that the action of the reaction medium can induce both partial deactivation (Pt–SnO_x) and activation (Au–SnO_x) of the catalysts. The Pd–SnO_x catalyst has a high activity even in the initial state, and the effect of the reaction medium is slight. It was shown that gold and platinum mainly exist in the metallic state, while palladium exists as PdO nanoparticles. Electron transfer between the active component and support particles was detected for the Pt–SnO_x and Au–SnO_x catalysts. Electron donation effect from the support, enhanced by the action of the reaction medium, was found for Au–SnO_x. This effect was assumed to determine the low-temperature activity of the catalyst towards the CO oxidation.