Direct Metal Substitution of Electropolymerized Ferriprotoporphyrin: A Simple Electrode-Modification Process for Developing Electrocatalytic Materials

A simple approach for expanding metalloporphyrins as electrocatalytic materials is introduced. This new method involves the direct electropolymerization of an electrically conducting layer of ferriprotoporphyrin followed by a metal-substitution reaction executed by soaking the electrode in an aqueous metal-salt solution. This process exchanges the iron center of the surface-bound protoporphyrin with the metal ion of the salt solution. X-ray photoelectron spectroscopy and electrochemical methods confirm that this new metal is incorporated into the surface-bound porphyrin structure and alters the electrochemical properties of the electrode. This simple electrode modification process may expand the use of metalloporphyrins for electrocatalytic applications. © 2013 The Electrochemical Society. [DOI: 10.1149/2.005310eel] All rights reserved.