The production of sorbitol from polysaccharides is widely believed to proceed via hydrolysis to glucose
and subsequent hydrogenation. Nevertheless, our previous study on the hydrolytic hydrogenation
of cellobiose confirmed simultaneous hydrolysis and hydrogenation with a higher kinetic selectivity
of hydrogenation over hydrolysis. Herein, kinetics of hydrogenolysis of trisaccharides with -1,4 and
-1,4 glycosidic linkages were studied using Ru/C in combination with a molecular acid as catalyst system.
Kinetic analysis emphasises a fast hydrogenation of the reducing end of trisaccharides followed
by a facilitated cleavage of the terminal sorbitol unit. Considering the obtained reaction rate constants,
hydrogenation compared to hydrolysis proceeds up to 24 and 15 times faster for maltotriose and cellotriose,
respectively. Additionally, superior reaction rate constants and decreased activation energies for
hydrolytic cleavage of sorbitol can be observed. Hence, a sequential hydrogenation-hydrolysis pathway
clearly contributes to sorbitol formation based on oligosaccharides.