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

Abstract

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.