Surface Engineering Protocol To Obtain an Atomically Dispersed Pt/CeO2 Catalyst with High Activity and Stability for CO Oxidation

Atomically dispersed metal catalysts often exhibit superior performance compared to that of nanoparticle catalysts in many catalysis processes. However, these so-called “single-atom” catalysts have a consistently low loading density on the support surface and easily aggregate at high temperatures, hindering their practical application. Herein, we demonstrate a facile surface engineering protocol using molecule–surface charge transfer adducts to fabricate highly stable noble metal catalysts with atomic dispersion, using a Pt/CeO2 catalyst as an example. The key of this approach is the generation of an adequate amount of Ce3+ defective sites on the porous CeO2 surface through the adsorption of reductive ascorbic acid molecules and a subsequent surface charge transfer process. Subsequently, noble metal Pt atoms can be well-dispersedly anchored onto the generated Ce3+ sites of porous CeO2 nanorods with a loading density of up to 1.0 wt %. The as-prepared highly dispersed Pt/CeO2 catalyst showed outstanding catalytic activity at near room temperature toward CO oxidation, with excellent stability over several days, which is far superior to the traditional impregnation-prepared catalysts, the activity (complete conversion at 90 °C) of which is severely decayed within a couple of hours. The proposed synthetic route is simple yet versatile and can therefore be potentially applied to fabricate other supported noble metal catalysts with atomic dispersion.