Performance improvement of polymer fuel cell by simultaneously inspection of catalyst loading, catalyst content and ionomer using home-made cathodic half-cell and response surface method

Abstract

The catalyst layer (CL) is the most important component in proton exchange membrane fuel cell (PEMFC) performance. Owing the properties of proton exchanging of Nafion, catalytic activity of Pt and electron transfer of carbon support, electrodes are prepared with different amounts of Nafion content, Pt loading and Pt% which are the catalyst layer composition parameters. Here we demonstrate the impact of these parameters to improve the performance of oxygen reduction reaction (ORR) in PEM fuel cell applications. Nafion content, Pt loading and Pt:MWCNTs percent are varied from 11 to 33 wt%, 0.1–0.5 mg cm−2 and 10 to 30 wt%, respectively. These parameters are investigated using a catalyst coated membrane electrode (CCME) assembling technique which is placed inside an in-house cathodic half-cell. Half-cell setup is used as an ex situ method in fuel cell studies, because it is the fastest and most cost-effective method for quick selection of electrode materials. The CCME composition conditions are investigated by design of experiment (DOE) proceeding which is performed with the response surface method (RSM) using the central composite design (CCD). The CCME is prepared with a Nafion 117 membrane and gas diffusion layer (GDL) having an active area of 0.785 cm2. The half-cell test results show that electrode with 0.50 mg cm−2 Pt loading, 28.78 wt% Pt% and 11.00 wt% Nafion in CL which predicted by mathematical model in the RSM, exhibits promoted behavior in ORR. The CCME with the predicted parameters shows the highest performance of 29.63 mW cm−2, which is confirmed experimentally.