Model Study of CNT-Based PEMFCs’ Electrocatalytic Layers

Abstract

One of the most important problems in the development of proton-exchange membrane fuel cells (PEMFCs) is the selection of an efficient support material to serve as the electrocatalyst, which can ensure PEMFCs’ durability at low active metal loading, with minimal changes in the electrochemical surface and conductivity during long-term operations. Carbon nanostructures are now widely used in PEMFCs as such support materials, including carbon nanotubes (CNTs). In order to estimate the effect of the geometric parameters of a CNT-based support on the resulting size distribution of platinum nanoparticles for given synthesis conditions, in this work, we propose a semi-empirical model that assumes a random uniform distribution of platinum particles over the CNT surface. Based on the obtained distribution, the electrochemically active surface area (EASA) of the electrocatalyst is calculated and further used to evaluate the performance of the catalytic layer (CL) in the PEMFC. The applicability of the proposed model for calculating the parameters of CNT-based CLs and the output electrochemical characteristics of PEMFCs is shown.

Keywords

• carbon nanotubes
• CNT-based platinum catalysts
• Ostwald ripening model
• PEM fuel cell
• catalytic layer