Temperature-Programmed Reduction Studies on Fe-promoted Pt/Al2O3 Bimetallic Catalysts

Abstract

Pt/Al2O3-based bimetallic catalysts were prepared using surface organometallic method (SOMC) to obtain catalysts with a nominal promoter to platinum surface atomic ratio of 1:2 and 1:1 (corresponding to typically 0.2–0.4 mass% of the promoting metals; here Fe). Temperature-programmed reduction (TPR) studies showed two distinct temperature regions of hydrogen uptake during reduction by the parent Pt/Al2O3 (5 mass%) and the Fe-promoted catalysts. The shift in peak maxima in the case of promoted catalysts to higher temperatures has been interpreted as a result of creation of interfacial sites responsible for improved performance of the bimetallic catalysts. Thermogravimetric and differential scanning calorimetric studies, performed in air and under H2/N2 atmosphere, supported the TPR results and confirmed the stability of catalytic systems up to 600°C.