Formation and Study of Porous Alumina and Catalytic Coatings by the Use of Cold Gas Dynamic Spraying Method

Cold gas dynamic spraying was used to obtain coatings based on γ-Al₂O₃ and Pd-CeO₂/γ-Al₂O₃ catalyst on a stainless steel foil. The coatings were studied by thermal cycling, BET, SEM, TEM, and XPS methods. The textural and adhesion characteristics of the coatings were found to depend on the composition of initial alumina powders with metallic aluminum (weight ratios of the components were varied from 2:8 to 8:2). It was shown that a mixture containing 25% γ-Al₂O₃ and 75% Al provides the optimal properties of the coatings. The effect produced by a method of the active component introduction into the coating on the catalytic properties of samples was examined. A considerable advantage of Pd introduction by impregnation in the preliminarily sprayed γ-Al₂O₃ layer over the direct spraying of the finished catalytic composition on the foil was demonstrated.