Chemoselective catalytic oxidation of glycerol
As shown in Scheme 3, seven potential C3 oxygenated
products – dihydroxyacetone, hydroxypyruic acid, mesoxalic
acid, glyceraldehydes (GLYALD), glyceric acid, tartronic
acid and hydroxymethyl glyoxal, together with C2 (oxalic
acid, hydroxyethanoic acid) and C1 products (formic acid,
COx) – can be obtained from the oxidation reaction of
glycerol. Selective versus nonselective oxidation is, therefore,
the big challenge associated with these catalytic oxidation
reactions. The first important step in the industrialization of
these new processes requires the design of new, effective
heterogeneous catalysts to control the chemoselective orientation
of the glycerol oxidation reaction towards either the
oxidation of the primary alcohol functions, to give glyceric
acid, or the oxidation of the secondary alcohol function, to
produce dihydroxyacetone and hydroxypyruvic acid.