Alumina supported bimetallic Pt–Fe catalysts applied to glycerol hydrogenolysis and aqueous phase reforming

• Published in: Applied catalysis. B, Environmental Environmental, 2016-05, Vol.185, p.77-87
• Main Authors: Soares, André Von-Held, Perez, Geronimo, Passos, Fabio B.
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Aqueous phase reforming; Catalysis; Catalysts; Chemisorption; Glycerol hydrogenolysis; Glycerols; Hydrogen; Hydrogenolysis; Platinum; Propanediol; Pt–Fe catalysts; Reforming
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2015.11.003

[Display omitted] •Ptx–Fey/Al2O3 showed better activity and selectivity towards 1,2-PD than Pt/Al2O3.•Pt–Fe interaction generates new active sites for glycerol hydrogenolysis.•Fe is reduced in the presence of Pt at 512K, forming active bimetallic particles.•Hydrogen formation from dehydration and dehydrogenation steps.•Glycerol APR over Ptx–Fey/Al2O3 catalysts for low temperature H2 production. Glycerol hydrogenolysis and aqueous phase reforming (APR) are processes that can transform glycerin into 1,2-propanediol (1,2-PD), ethylene glycol (EG), alcohols, ketones and hydrocarbons. This study was performed using five Ptx–Fey/Al2O3 catalysts in both glycerol hydrogenolysis and APR reactions, with 2.5%wt. metallic Pt total loading and varying Pt:Fe atomic ratios (1:0; 0:1; 2:1; 1:1; 1:2). The catalysts were analyzed by XRD, TPR, XPS, FT-IR, TEM, N2 physisorption and H2 chemisorption, and catalytic tests were undertaken in batch reactions. Except for Fe/Al2O3, all catalysts were active for both APR and hydrogenolysis reactions, in which bimetallic Ptx–Fey/Al2O3 showed better selectivity towards 1,2-PD than Pt/Al2O3. From characterization, it is clear that Pt–Fe interaction displays a pivotal role in enhancing catalytic activity, through the generation of new sites. From the catalytic tests, rate constants and TOF’s were calculated. The addition of Fe had a positive effect both in activity and in selectivity for hydrogenolysis towards 1,2-PD. In APR, there is considerable H2 production, and although activity is greater, there is a slight decline in 1,2-PD production. Through comparison of both reactions’ products, it is evident that some of the hydrogen used in glycerol hydrogenolysis comes from glycerol reforming. Glycerol APR over Ptx–Fey/Al2O3 catalysts seems to be a viable alternative for low temperature H2 production.