Study of the Reducibility of Pt or Pd on Ceria-Zirconia Catalysts by XANES measured and the Ce LIII Edge and Magnetic Susceptibility Measurements

The reduction behaviour of Ce x Zr1–x O2 and Pt or Pd supported on Ce x Zr1–x O2 was investigated by means of XANES measured at the Ce LIII edge and magnetic susceptibility measurements. Both techniques agree quite closely for the materials studied. The presence of a noble metal greatly improves the reduction of the Ce x Zr1–x O2 support at low temperatures. The reoxidation that occurred after evacuation of the reduced solids and heating to 500°C suggests that it is linked to a reversible surface reduction process of the sample.