Revolutionizing high-temperature polymer electrolyte membrane fuel cells: Unleashing superior performance with vertically aligned TiO2 nanorods supporting ordered catalyst layer featuring Pt nanowires

Abstract

For large-scale commercialization of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs), the issues of high Pt loading and unsatisfactory durability must be addressed. Disordered cathode catalyst layer (CL) with the random distribution of Pt/C electrocatalysts, binders, and pores is proved as one main reason for the motioned issues due to the limited Pt utilization efficiency, tortuous mass transport, and poor stability of Pt/C. Herein, we construct an ordered cathode CL consisting of in-situ grown Pt nanowires on the vertically aligned TiO2 nanorods array, coupled with carbon nanotubes as conductors to enhance the mass transfer characteristics and durability. In the single cell tests, the membrane electrode assembly (MEA) with ordered cathode CL achieves 3.53-fold Pt mass-specific peak power density compared to a conventional MEA. The Pt loading is only 20 % of the latter. Meanwhile, much better durability is confirmed. The superior performance and durability are attributed to the synergistic effects of ordered structure, stable TiO2 nanorods, one-dimensional features of Pt nanowires, and strong metal-support interaction between TiO2 and Pt. This work provides new insight into CL design and facile fabrication method of the ordered CL, which is of great significance for the large-scale application of HT-PEMFC.