Importantly, a cyclic voltammetry study on the electrochemical property of the heterogenized iron complex suggested redox events associated with surface-bound species similar to the homogeneous case. Additionally, the polymer chains remained attached to the surface without cleavage. Inspired by the selective behavior of electrochemically controlled iron(II)/(III) catalyzed polymerization, a substrate containing two electrically isolated domains was used to demonstrate the spatial control of polymer composition by exposing one domain to an oxidizing potential, which resulted in patterns of polylactide (PLA) and polycyclohexene oxide (PCHO) through the sequential addition of the two corresponding monomers. It is noteworthy that exposing a combination of iron(II) and iron(III) functionalized electrodes in the mixture of lactide and cyclohexene oxide resulted in the chemoselective growth of PLA and PCHO on the iron(II) and iron(III) electrode, respectively, while exposing two electrically isolated domains to a mixture of monomers also resulted in selective polymerization. This study demonstrates a successful case of electrochemically controlled polymerization via a molecular functionalized electrode surface in which an electrical potential altered the redox state of the immobilized catalyst, therefore affecting the catalyst's reactivity and enabling a selective polymerization of two monomers. As a result, a spatially controlled surface polymerization pattern was achieved by switching the oxidation state of the iron complexes on two isolated domains in one system. One of the limitations of immobilizing metal complexes through directly ligating the active metal center to the surface is that as the polymerization proceeds, the metal moves further away from the surface, which may result in an inefficient electron transfer from the electrode surface to the catalyst. Secondly, the redox property of the complex directly connected to the surface via a hydroxyl linkage differs from the polymer-bound metal complex after the polymer chain is formed. Nonetheless, this study demonstrated proof-of-concept case for achieving an on/off switch in polymerizing different monomers by electrochemically triggered redox events.