Critical Influence of Nanofaceting on the Preparation and Performance of Supported Gold Catalysts

A partial transformation of the {100} surfaces of ceria nanocubes into a set of nanometer-heighted, {111}-bounded, peaks was achieved by an oxidation treatment at 600 °C. This particular type of surface nanostructuration allows the preparation of CeO₂ nanoparticles in which {111} nanofacets contribute significantly to their surface crystallography. This transformation of the surface structure plays a key influence on the behavior of ceria as a support of gold catalysts. Thus, the appearance of well-developed {111}-nanofacets leads to a much higher efficiency in the usage of this noble metal in the synthesis of catalysts when prepared by the deposition–precipitation method. Moreover, gold catalysts supported on the surface-reconstructed oxide present an intrinsic (per gold surface atom) CO oxidation activity much higher than that of catalysts prepared on the nontreated oxide