Improvement of performance and degradation durability of Pt electrocatalyst using nitrogen-doped TiO2 support

Abstract

Polymer electrolyte membrane fuel cells (PEMFC) are attracting attention as next-generation energy converters due to their environmentally friendly products and high energy conversion efficiency. Carbon-based supports with high surface area and electrical conductivity are widely used as catalyst supports used in PEMFC. However, the use of non-carbon supports has been proposed for carbon-based supports because of the degradation of catalytic performance due to electrochemical oxidation under PEMFC long-term operating environment. Titanium dioxide, a non-carbon support, has strong durability under the operating conditions of PEMFC, but due to the characteristics of metal oxides, it suffers from the disadvantages caused by low electrochemical properties compared to carbon-based supports. In this study, titanium dioxide and urea were annealed in a hydrogen atmosphere to produce nitrogen doped titanium dioxide (TiON) with high electrochemical properties and high acid resistance, and the physicochemical properties of TiON. Properties were analyzed through XRD, FE-TEM and XPS. In the electrochemical analysis, the oxygen reduction ability was measured by the linear scanning voltammetry (LSV), and the electrochemical surface area (ECSA) analysis was performed by the cyclic voltammetry (CV). Pt/TiON shows high durability in oxygen reduction reaction compared to commercial Pt/C as a result of accelerated durability test (ADT) in the high voltage range (1.0 V to 1.5 V). Furthermore, improvement of performance and degradation durability of the Membrane-electrode assembly (MEA) was confirmed.