Heterogeneous catalysis of the glycerol hydrogenolysis

Glycerol has become an important feedstock for chemicals. Selective hydrogenolysis of glycerol has been attempted using several types of catalysts: non-noble-metal catalysts, noble-metal catalysts with an acid as an additive, noble-metal catalysts combined with a base, and metal-oxide-modified noble-metal catalysts. The former three approaches give 1,2-propanediol as a main product, while the mechanisms may be different. Only the last one can selectively give the more valuable 1,3-propanediol.