The influence of mass-transport conditions on the ethanol oxidation reaction (EOR) mechanism of Pt/C electrocatalysts

This study aims to provide further understanding of the influence of different parameters that control mass-transport (the revolution rate of the rotating disk electrode and the potential scan rate) on the ethanol oxidation reaction (EOR).

Using ordered carbon nanomaterials for shedding light on the mechanism of the cathodic oxygen reduction reaction

Insufficient understanding of the mechanism of the cathodic oxygen reduction reaction puts constraints on the improvement of the efficiency of polymer electrolyte fuel cells (PEMFCs). We apply ordered catalytic layers based on vertically aligned carbon nanofilaments and combine experimental rotating ring-disk studies with mathematical modeling for shedding light on the mechanism of the oxygen reduction reaction on Pt nanoparticles. Based on the experimental and simulation evidence we propose a dual path ORR mechanism which comprises a "direct 4e(-)" and a "series 2e(-) + 2e(-)" pathway and explains switching between the two. For the first time we show that below 0.8 V the "direct" path may be discarded and the ORR predominantly occurs via H(2)O(2) mediated pathway, while in the potential interval between ca. 0.8 V and the onset of the ORR the "direct" path is dominating.