The oxidation of glycerol using a range of metal-containing silicalite and aluminophosphate catalysts is described and discussed. Variation in reaction conditions (extent of conversion, temperature, glycerol/hydrogen peroxide ratio) or catalyst (silicalite containing Ti, V, Fe or AlPO-5 containing Cr, V, Mn, Co) did not lead to the formation of partial oxidation products of glycerol. Formic acid and a mono-formate ester of glycerol were observed to be the major products together with a complex mixture of acetals. Increasing the pore size of the catalyst was investigated for Ti-containing materials and it was found that increasing the pore size from ca. 0.5 nm for TS-1 to 15 nm for a titania-silica co-gel significantly increased the formation of partial oxidation products of glycerol, namely glyceraldehyde, dihydroxyacetone and glyceric acid.