Abstract

The microaerial oxidation of an aqueous solution of lactose to lactonionic acid (LBA) over the heterogeneous bimetallic catalyst Bi-Pd supported on mesoporous SBA-15 material was carried out in an agitated semi-batch reactor in alkaline medium within the pH range of 7 to 9.

The present work focused on the synthesis and characterization of the bimetallic catalyst as well as optimization of the reaction operating conditions. To this purpose, the effect of both active metals loading on the support, metal/lactose ratio, reaction pH and dissolved oxygen concentration on the oxidation performances was examined at a very mild temperature of 65 ^oC.

The bimetallic catalyst 1.02%Pd, 0.64%Bi/SBA-15, (Bi/Pd molar ratio of 0.3) showed the highest activity (96 % lactose conversion) and 100 % selectivity towards the targeted LBA product. Furthermore, the formulated catalyst proved to be stable in the reaction medium as both metals leaching was insignificant. Based on XRD and XPS analyses, it is suggested that the metals constituting the bimetallic catalyst active sites assemble into an intermetallic alloy having Bi_1.75Pd stoichiometry.

Recommended Citation

Belkacemi, Khaled; Cristea Vlad, Mirela; Hamoudi, Safia; and Arul, Joseph (2007) "Value-Added Processing of Lactose: Preparation of Bioactive Lactobionic Acid Using a Novel Catalytic Method," International Journal of Chemical Reactor Engineering: Vol. 5: A64.
Available at: http://www.bepress.com/ijcre/vol5/A64