Highly Durable and Active Pt Nanorod Electrocatalysts Using SnO2 Supports for Polymer Electrolyte Fuel Cells

Abstract

ABSTRACT Toward the widespread use of fuel cell vehicles, highly durable and active catalysts in polymer electrolyte fuel cells (PEFCs) are required. Pt catalysts supported on non-carbon ceramic supports were proposed to be alternative candidate catalysts with high activity and high durability [1,2]. Our group also confirmed that Pt catalysts supported on SnO2 (Pt/M-SnO2, M = Nb, Ta) without carbon additive were superior in oxygen reduction reaction (ORR) activity with durability (startup/shutdown, load cycling) to those of commercial Pt catalysts supported on carbon (e.g., Pt catalysts supported on either graphitized carbon black (Pt/GCB, TEC10EA30E, TKK) or carbon black (Pt/CB, TEC10E30E, TKK), by evaluation of rotation disk electrode and single cell [3-9]. Our non-carbon support of SnO2 nanoparticles has quite high crystallinity with unique carbon-like microstructure consisting of a fused-aggregate network structure, which enhances the electronically conducting pathways via the aggregated microstructure and gas diffusion pathways via the open pores in the microstructure. The Pt nanorods loaded on the supports with controlling the interface between Pt and the support also enhance the ORR activity, and mitigate the resistance of the cathode catalyst layer (CL). The cell performance using the Pt nanorods loaded on the supports cathode CL is quite promising for the development of high power density with simultaneous high durability at operating temperatures from 80oC to 120oC. Acknowledgments This work was partially supported by funds for the partly supported by the New Energy and Industrial Technology Development Organization (NEDO) Japan, and JSPS KAKENHI Grant Number (B24350093) from the Ministry of Education, Culture, Sports, Science and Technology.