The oxidation of hexanol in the presence of the Keggin-type heteropoly compounds (HPCs) H3PMonW12-nO40 (denoted as PMonWI2-n, n=0.1) and Na(5)PW(11)ZO(39) (denoted as PW(11)Z, Z = Mn, Fe, Co, Ni, Cu and Zn) was carried out to produce hexanal and hexanoic acid. The reaction was conducted in tert-butanol (t-BuOH), using cetylpyridinium bromide (CPB) salts of HPA and 15% aqueous H2O2 as oxidant under mild conditions. The PMoW11 catalyst showed higher hexanol conversion of 25%, the lowest selectivity to hexanal of 64.4% and an efficient utilization of H2O2 of 34%. Over the transition metal substituted PW(11)Z catalysts decomposition of H2O2 was rapid. For these PW(11)Z catalysts, the efficient utilization of H2O2 decreased to 9% or even lower. By means of IR, UV-visible and GC-MS techniques the catalysts were characterized.an efficient utilization of H