Gb. Hoflund et al., INFLUENCE OF AN FE PROMOTER ON SILICA-SUPPORTED PT SNOX CATALYSTS USED FOR LOW-TEMPERATURE CO OXIDATION/, Catalysis letters, 31(2-3), 1995, pp. 133-141
Silica-supported Pt/SnOx catalysts used for low-temperature CO oxidati
on have been prepared without and with an Fe promoter. Reaction studie
s demonstrate that the addition of the Fe promoter results in higher c
atalytic activity in the presence of 8 at% CO2 and a lower decay rate.
Ion scattering spectroscopy (ISS) has been used to examine the outerm
ost atomic layers of the promoted and nonpromoted catalysts before and
after activation by a reductive pretreatment. The nonpromoted catalys
t exhibits agglomeration of the platinized tin oxide film exposing the
catalytically inactive silica support. This agglomeration does not oc
cur when Fe is present, and a large catalytically active surface area
is maintained during the reduction.