Ai Nozaki, Tasuku Yasuoka, Yasutaka Kuwahara, Tetsutaro Ohmichi, Kohsuke Mori, Takeshi Nagase, Hiroyuki Y. Yasuda, Hiromi Yamashita
Industrial and Engineering Chemistry Research 57(16) 5599-5605 2018年4月 査読有り
© 2018 American Chemical Society. Au-CeO2 catalysts are prepared from amorphous Ce-Al alloys by the dealloying method, and their catalytic performances are examined in the oxidation of benzyl alcohol to benzaldehyde using O2 as an oxidant. The catalytic activity of the Au-CeO2 catalysts is improved using an amorphous alloy as a precursor, and further improved activity is attained by directly alloying Au with Ce-Al rather than by depositing Au on preformed CeO2. Consequently, Au-CeO2 prepared directly from an amorphous Au-Ce-Al alloy exhibits the highest activity among the prepared samples, despite its low surface area. Detailed characterization by means of XPS analysis indicates that most of the Au species in Au-CeO2 prepared from the amorphous Au-Ce-Al alloy exist in a +1 oxidation state (Au+). The presence of Au+ facilitates the migration of oxygen atoms through the lattice, which likely contributes to the high catalytic activity of the Au-CeO2 catalyst.