Atomic layer deposition of ultrathin layered TiO2 on Pt/C cathode catalyst for extended durability in polymer electrolyte fuel cells

Abstract

This study shows the preparation of a TiO2 coated Pt/C (TiO2/Pt/C) by atomic layer deposition (ALD), and the examination of the possibility for TiO2/Pt/C to be used as a durable cathode catalyst in polymer electrolyte fuel cells (PEFCs). Cyclic voltammetry results revealed that TiO2/Pt/C catalyst which has 2 nm protective layer showed similar activity for the oxygen reduction reaction compared to Pt/C catalysts and they also had good durability. TiO2/Pt/C prepared by 10 ALD cycles degraded 70% after 2000 Accelerated degradation test, while Pt/C corroded 92% in the same conditions. TiO2 ultrathin layer by ALD is able to achieve a good balance between the durability and activity, leading to TiO2/Pt/C as a promising cathode catalyst for PEFCs. The mechanism of the TiO2 protective layer used to prevent the degradation of Pt/C is discussed. © 2016 Science Press and Dalian Institute of Chemical Physics. All rights reserved.