Homogenous electro-catalyst such as iron (III) tetra-phenyl porphyrins (FeTPP) showed an efficient transformation of CO2-to-CO in organic and aqueous media[1]. To improve the catalytic durability and enhance the catalytic efficiency, heterogeneous electro-catalysts were prepared by the intercalation of (4-sulfonatophenyl)-porphyrin-Fe(III) chloride (FeTSPP) in layered double hydroxides (LDH)[2] and layered simple hydroxides (LSH)[3]. The structural and morphological characteristics of ZnCr-FeTSPP LDH and Zn-FeTSPP LSH were compared. Then, the electroactivity of immobilized FeTSPP was tested in different electrolytes under inert atmosphere Ar or in the presence of CO2. Based on these results, a preparative scale electrolysis was performed to determine the selectivity and the faradic efficiency of the transformation of CO2 to CO. Preliminary results indicated that electrolysis performed in presence of immobilized Fe porphyrin do not lead as expected to CO formation but selectively to H2 production. Assumptions about these results will be discussed.