Unscrambling illusory inhibition and catalysis in nanoparticle electrochemistry: Experiment and theory

Recent theoretical work (Applied Materials Today 15 (2019), pp. 139-144) has demonstrated that the cyclic voltammetry of particle-modified electrodes bears a significant level of complexity: Altered mass transport inside the porous layer gives rise to effects that may falsely suggest positive or negative catalysis. This communication reports experimental work that validates this theory. Using the well-studied oxidation of ferrocenemethanol at glassy carbon, we describe experiments in the presence of non-conducting electrochemically-inert microspheres that reproduce trends in the theoretical predictions and illustrate how experimental results may mislead. In addition, we present experimental data of the reduction of oxygen at glassy carbon electrodes modified with Nafion microspheres and show that, unless compared with theoretical work, an electrocatalytic activity of Nafion may falsely be inferred. (C) 2019 Elsevier Ltd. All rights reserved.