Hydrogen production on alumina-supported platinum catalysts

• Published in: Molecular catalysis Vol. 429; pp. 1 - 9
• Main Authors: Martins, André Rosa, Carvalho, Luciene Santos, Reyes, Patrício, Grau, Javier Mario, Rangel, Maria do Carmo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2017
• Subjects: Al-Mg spinel; Alumina; Hydrogen; Platinum; Steam reforming; Steam reforming; Al-Mg spinel; Hydrogen; Platinum; Alumina
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.molcata.2016.11.040

[Display omitted] •Magnesium affects the properties of alumina-supported platinum catalysts.•Magnesium changes the activity of platinum on alumina catalyst in methane reforming.•Magnesium changes the activity of platinum on alumina in WGSR.•Magnesium affects hydrogen selectivity of platinum on alumina catalyst in reforming. Hydrogen production is commercially performed by methane steam reforming over alumina-supported nickel catalysts, which deactivate by coke requiring improved catalysts. Aiming to find alternative catalysts for the reaction, the properties of Pt/Al2O3-MgO catalysts were studied in this work. It was found that small amounts of magnesium (Al/Mg (molar)=5) enter into alumina lattice and produce magnesium aluminate on the surface. For higher amounts (Al/Mg=2) only magnesium aluminate is produced. For even higher contents (Al/Mg=0.2) aluminum enters into magnesia lattice, producing magnesia and magnesium aluminate on the surface. The specific surface area, acidity and platinum dispersion changed with magnesium amount, the aluminum-richest catalyst (Al/Mg=5) showing the highest values. Consequently, the activity and selectivity of the catalysts change in methane steam reforming and in water gas shift reaction, different values of products yield and H2/CO being obtained. The sample with Al/Mg=5 is the most promising catalyst to produce hydrogen.