Effective strategy for enhancing the activity and durability of gas diffusion electrode in high-temperature polymer electrolyte membrane fuel cells: In-situ growth of Pt nanowires on dual microporous layers

Abstract

High-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) suffer from high platinum (Pt) loading and limited lifetime issues due to the low Pt efficiency of the conventional electrode and poor durability of Pt/C catalyst under harsh operating conditions. Thus, dual microporous layer (MPL) structured gas diffusion layers were developed, utilizing formic acid reduction for the in-situ growth of Pt nanowires (NWs). The optimal ratio of the hydrophilic and hydrophobic MPLs was determined to be 1:1. The resulting Pt NWs gas diffusion electrode (GDE) achieved a significantly high Pt mass-specific peak power density, which was 2.48 times higher than the conventional Pt/C GDE. After accelerated degradation tests, the peak power density and the electrochemically active surface area of Pt NWs GDE decreased by 10.84 % and 4.47 %, respectively, significantly lower than those of the conventional Pt/C GDE. The superior activity and durability of Pt NWs GDE are attributed to its binder-free characteristic, the outstanding activity and stability of one-dimensional Pt NWs, and the strong adherent force between the in-situ grown Pt and the carbon substrate. This study provides a straightforward and effective strategy to reduce the Pt loading and enhance electrode durability, thereby facilitating the large-scale application of HT-PEMFCs.