The catalytic activity and durability of TiO2-nanoparticles catalyst for oxygen reduction reaction

Abstract

In this work, titanium dioxide nanoparticles (TiO2-NPs) with different particle sizes are used as a non-platinum cathode catalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). The microstructures of TiO2-NPs are characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD) and small-angle X-ray scattering (SAXS). The oxygen reduction reaction (ORR) activity and durability of the TiO2 catalysts 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 0.6-1.0 V vs. RHE, the ORR activity of all TiO2 catalysts increases. The results shed light on the ORR activity and durability of TiO2-NPs catalysts.