Structure of ReO x Clusters Attached on the Ir Metal Surface in Ir–ReO x /SiO 2 for the Hydrogenolysis Reaction

The structural change of Ir/SiO 2 and Ir–ReO x /SiO 2 during the temperature programmed reduction with H 2 was investigated using in situ Ir L 3 -edge and Re L 3 -edge quick-scanning X-ray absorption fine structure in the combination of temperature programmed reduction with H 2, XRD, the measurement of CO adsorption, Raman spectroscopy, and X-ray photoelectron spectroscopy. The metal oxide on Ir–ReO x /SiO 2 was much more easily reduced than that on monometallic Ir/SiO 2 and ReO x /SiO 2, which is explained by the interaction between trioxo Re species and the IrO 2 phase. The metal structure of Ir–ReO x /SiO 2 constructed after reduction at 485–595 K is the cuboctahedron Ir metal particles covered with three-dimensional ReO x clusters.