Electrochemical behavior of titanium oxide nanoparticles for oxygen reduction reaction environment in PEM fuel cells

Abstract

In this work, the oxygen reduction reaction (ORR) activity of titanium dioxide nanoparticles (TiO2-NPs) with different particle sizes is investigated in the acidic environment. The microstructures of the TiO2-NPs are characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction analysis (XRD). The oxygen reduction reaction (ORR) activity and durability of the TiO2-NPs are then investigated by cyclic voltammetry (CV) in N2 and O2 saturated 0.1 M HClO4 electrolyte and accelerated stability test (AST) using rotating disk electrode (RDE) technique. The results show some ORR activity for TiO2-NPs strongly depending on particle size. The durability of TiO2 catalysts, however, is remarkable. After 5000 potential cycles from 0.6 to 1.0 V vs. RHE, the ORR activity of all TiO2 catalysts increases. The results shed light on the ORR activity and durability of TiO2-NPs.