Enhancement of Oxygen Reduction Activity of Titanium Nano-Oxide-Based Electrocatalysts for PEFC Cathode

Development of non-platinum electrocatalyst for oxygen reduction reaction (ORR) is required for commercialization of polymer electrolyte fuel cells. We focused on titanium, which is inexpensive and has large amount of resources. Recently, we found that titanium oxide-based compounds made from titanium-organic complexes with oxidation under low oxygen partial pressure had high ORR activity. In this study, we prepared titanium oxide-based ORR catalysts (Ti-CNOs) by conducting ball-mills in dry process or impregnation method with N -methylpyrrolidone as a solvent. We found that the Ti-CNOs prepared by ball-milling in dry process showed high rest potential and large ORR current density. The highest rest potential of the ORR on the Ti-CNOs was over 1.0 V vs. RHE, indicating that titanium oxide-based catalysts are promising as an alternative ORR catalyst.