Stabilized gold on cerium-modified cryptomelane: Highly active in low-temperature CO oxidation

The interplay of stabilized (sub)-nanosized gold species, cryptomelane, and cerium (as dopant and ceria nano-particles) results in a highly active gold catalyst for the low-temperature oxidation of CO. [Display omitted] •Cerium-doped cryptomelane stabilizes polyhedron Au nano-particles smaller than 3nm.•The obtained Au/Ce/cryptomelane catalyst is highly active for CO oxidation.•Cationic, neutral, and anionic gold species were found on Ce/cryptomelane.•Ce increases the number of defect sites and charge transfer between Au and KOMS-2.•TOF for Au/Ce–K-OMS-2 is about twice that of Au/CeO2 prepared by the same procedure. Cerium-doped cryptomelane stabilizes polyhedron Au nano-particles smaller than 3nm. The obtained Au/Ce/cryptomelane catalyst is highly active for CO oxidation. Cationic, neutral, and anionic gold species were found on Ce/cryptomelane. The modification of cryptomelane by the addition of cerium is twofold: (i) cerium is incorporated in the tunnels of cryptomelane, increasing the number of defects which function as nucleation sites for gold and (ii) ceria nano-particles at the surface induce charge transfer between gold and cryptomelane. TOF for Au/Ce–K-OMS-2 is about twice that of Au/CeO2 prepared by the same procedure.