Effect of Manganese Porphyrin Covalent Immobilization on Electrocatalytic Water Oxidation and Oxygen Reduction Reactions
By Marianov, Aleksei N.; Jiang, Yijiao
Published in ACS Sustainable Chemistry & Engineering
2019
Abstract
Complexes of first row transition metals are a promising class of tunable and inexpensive catalysts for electrochemical energy applications. Although considerable efforts have been devoted to the activity studies, little attention has been paid to the effects of different immobilization modes on reaction mechanisms. In this work, we studied the influence of covalent immobilization on the performance of Mn tetraphenylporphyrin in oxygen evolution (OER) and oxygen reduction (ORR) reactions. Ligation of the complex to carbon surface was attained via potentiostatic electroreduction of porphyrin diazonium salt with the following metalation and electrodeposition time was found to be a convenient tool to control the amount of electrochemically active catalyst on the electrode. Cyclic voltammetry suggests that the increase of porphyrin surface concentration upon prolonged electrodeposition shortens average Mn