A new soluble inorganic–organic hybrid based on polyoxotungstate, [Himi] 4 [SiW 12 O 40 ].H 2 O 1 (imi = Imidazole), has been successfully synthesized and characterized by using elemental analysis, infrared spectrum, 1 H NMR technique and single-crystal X-ray diffraction. X-ray crystallography reveals that 1 displays an organic–inorganic hybrid frameworks constructed by [SiW 12 O 40 ] 4− α-Keggin-type polyoxoanion and four {(Himi)} + monocationic hydrogen-bonded fragments. Redox activities for the tungsten centers have been observed using cyclic voltammetry. It was found that 1 presents good electrocatalytic activities for the reduction of NO2− rather than H 4 SiW 12 O 40 heteropolyacid.