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

2013; Elsevier BV; Volume: 309; Linguagem: Inglês

10.1016/j.jcat.2013.08.030

1090-2694

Vera P. Santos, Sónia A. C. Carabineiro, J.J.W. Bakker, O.S.G.P. Soares, Xiaowei Chen, M.F.R. Pereira, J.J.M. Órfão, José L. Figueiredo, Jorge Gascón, Freek Kapteijn,

Nanomaterials for catalytic reactions

Cerium-doped cryptomelane stabilizes polyhedron Au nano-particles smaller than 3 nm. 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.