A new Keggin-type mono nickel substituted phosphotungstate was functionalized by imidazole following a ligand substitution method and characterized in solid as well as in solution by various physicochemical techniques including elemental analysis, TGA, FT-IR, Multinuclear solution NMR (P-31, H-1), UV-Vis, and cyclic voltammetry. The catalytic activity was evaluated for oxidation of styrene under non-solvent liquid phase conditions using environmentally benign oxidants such as O-2 and H2O2, varying different parameter.