Systems, methods and compositions for reducing the heteroatom content of hydrocarbon feed using transition metal complexes and adsorption techniques. The transition metal complexes include titanyl, hafnyl and zirconyl complexes activated using one or more hydroperoxides or peracids. The activated adsorbents are incorporated into one or more vessels as an adsorption bed for adsorbing the heteroatoms present in hydrocarbon feeds. The systems, methods and compositions separate the heteroatoms passed through the system by contacting the adsorption compositions with the heteroatoms of the hydrocarbon feed, adsorbing the heteroatom to the adsorption material, further allowing for the retrieval of a hydrocarbon product having a reduced heteroatom content.