Abstract

Various bimetallic (i.e., Au-M, where M=Pd, Cu, Co or Fe) gold-containing catalysts were prepared and tested for the oxidation of α-pinene. All catalysts were prepared by impregnation method on TiO2 support and compared to determine the best and most active catalyst for the selective oxidation of α-pinene. Although, the reaction resulted in the formation of a variety of products including: pinene oxide, verbenol, verbenone, carveol, and carvone, however the emphasis was on studying the effect of increasing the catalytic mass and reaction time, particularly during the conversion of α-pinene to pinene oxide. Other catalysts namely, CoCu, Cu, PdCu, FeCu, Pd and Fe were studied for comparison. After 24 hours, the catalytic activity of all the studied systems was observed to be in the order of: CoCu>Cu>AuCu>PdCu>FeCu>PdAu>Au>Pd>Fe>AuFe. Furthermore, the bimetallic AuFe/TiO2 system was found to be the best and most active catalyst for the selective conversion of α-pinene to pinene oxide after 24 hours at a temperature of 70 °C. The mass of the catalyst and reaction time greatly influenced the oxidation rate of α-pinene.

Keywords: Bimetallic catalyst; α-pinene; Gold catalyst; Green monomers