Nanostructured Pt-γ-Al2O3-CeO2 catalytic materials and coatings

A new process is described for the suspension synthesis of polycrystalline Pt-γ-Al 2 O 3 -CeO 2 catalytic materials and coatings, with maltose, C 12 H 22 O 11 , as a reductant and structure former. The process parameters have been optimized in terms of the dispersion medium composition and the way in which Pt is introduced. The coatings are highly uniform in chemical and phase composition, as evidenced by quantitative analysis, optical microscopy, and x-ray microanalysis results. Characteristically, the coatings have a highly porous structure and good adhesive properties. Catalysts prepared by the proposed process show high activity for the oxygen oxidation of CO. The process can be used to fabricate Pt-Pd-Rh catalysts on block supports for the purification of vehicle exhaust gases and industrial off-gases. It has the advantage that high-porosity multicomponent catalytic coatings can be produced on cordierite block supports in a single step.