Selective hydrogenolysis of glycerol to 1,2-propanediol on Nb-modified Pd - Zr - Al catalysts

Here, the Nb-modified Pd - Zr - Al catalysts with different Nb loadings were prepared and evaluated for glycerol hydrogenolysis to 1,2-propanediol. Characterization studies revealed that the addition of Nb to Pd - Zr - Al catalyst not only favored the reduction of PdO species, but also enhanced the acid strength and Pd dispersion on catalyst surface, which led to increased catalytic activity for glycerol hydrogenolysis. The optimal 8Nb/Pd - Zr - Al catalyst obtained 69.2% glycerol conversion and 84.5% 1,2-propanediol selectivity with a stable activity and a good reusability at 200 degrees C and 3.5 MPa H-2, attributable to high Pd dispersion and strong interaction between the Pd and Nb species.