Catalytic properties of SrSn1-xSbxO3 in methanol oxidation

Ceramic model catalyst materials of general formula SrSn1-xSbxO3 are synthesised by solid state reaction. X-ray diffraction shows the materials to be single phase over the composition range 0 ≤ x ≤ 0.085, with a second phase, identified as SrSb2O5, being produced at higher antimony doping levels. XPS, Auger electron spectroscopy and valence band photoemission show strong segregation of Sb to the surface of the material even within the single phase regime. The catalytic properties of the materials are examined using methanol oxidation as a test reaction. The activity and selectivity to formaldehyde production shown by these materials is found to be strongly correlated with the attainment of the bulk solubility limit of Sb in the SrSnO3 perovskite host.