The air oxidation of ethylbenzene in liquid phase at atmospheric pressure catalyzed by nickel acetylacetonate was investigated. The catalyst was supported on a variety of polyvinylpyridines as homopolymers or crosslinked with divinylbenzene. In addition, a co-catalyst based on N-n-butylpolyvinylpyridinium hexafluorophosphate was employed. Results show that the poly-2-vinylpyridine-divinylbenzene based catalyst gives the best results in terms of both ethylbenzene conversion and ethylbenzene hydroperoxide selectivity.