Catalysis Letters, Vol.128, No.3-4, 323-330, 2009
The Influence of Thermal Treatment and Noble Metal Addition on Hopcalite Activity in Oxidation of Thiophene
In this paper the comparison of activity of hopcalite (Mn-Cu mixed oxides) modified with noble metals (Pd, Pt and Au) calcined at 300, 400 and 500 degrees C in oxidation of thiophene was presented. Hopcalite modified with Pd demonstrated the highest activity among the studied samples, thus the results of a more detailed study of the most promising palladium catalyst were also shown. Surface and bulk properties of catalyst were studied with BET, XRD, TPRH2 and TG-DTA-MS. The redox properties and distribution of active components on the catalyst surface seem to be important factors influencing the modified hopcalite performance in the oxidation reactions. It was found that irreversible changes occurred during thermal treatment in the Pd-modified hopcalite structure, however they have no marked influence on activity of modified catalysts.