Catalytic Pt/Al₂O₃ Monolithic Foam for Ethanol Reforming Fabricated by the Competitive Impregnation Method

Here, the synthesis of Pt/Al₂O₃ catalysts on a monolithic foam employing the competitive impregnation method is presented. NO₃ ^- was used as a competitive adsorbate at different concentrations in order to delay the adsorption of Pt, minimizing the formation of Pt concentration gradients throughout the monolith. The catalysts' characterization includes the BET, H₂-pulse titration, SEM, XRD and XPS techniques. The catalytic activity evaluation was performed under partial oxidation and autothermal reforming of ethanol in a short contact time reactor. The competitive impregnation method was able to produce better dispersion of the Pt particles through the Al₂O₃ foams. XPS analysis indicated the catalytic activity of the samples, by the presence of metallic Pt and Pt oxides (PtO and PtO₂) in the internal regions of the monoliths. Compared to other Pt catalysts reported in the literature, the catalyst produced by the competitive impregnation method was revealed to be selective toward H₂. Overall, the results showed that the competitive impregnation method employing NO₃ ^- as the co-adsorbate is a promising technique to synthesize well dispersed Pt catalysts over α-Al₂O₃ foams.