Effective Utilization of Carbon Nanocoil-supported PtRu Anode Catalyst by Applying Anode Microporous Layer for Improved Direct Methanol Fuel Cell Performance

The application of a microporous layer (MPL) between the gas diffusion layer and the catalyst layer (CL) plays a crucial role in the performance of the direct methanol fuel cell (DMFC). To this end, this study investigates the effects of carbon loading and the nature of the carbon material used in the anode MPL on the performance of DMFC using transmission and scanning electron microscopy, polarization technique, and electrochemical impedance spectroscopy (EIS). DMFC was indigenously fabricated using 30 wt% PtRu catalyst supported on carbon nanocoil and commercial Pt catalyst as the anode CL and the cathode CL, respectively. Carbon nanoballoon (CNB) and Vulcan XC-72R (Vulcan) were used as the anode MPL. According to polarization studies, a membrane electrode assembly (MEA) with CNB and Vulcan MPLs (loading of 1.5 mg cm(-2)) shows higher power density. This is 1.3 and 1.8 times higher than that without the anode MPL when methanol concentration was 0.5M (M = mol dm(-3)), respectively. Electrochemical impedance spectra (EIS) results indicate that the MEAs with the anode MPLs have lower high-frequency resistance and charge transfer resistance when compared to those without the anode MPL. Thus, it can be realized that the anode MPL plays a significant role in the effective utilization of CNC-supported PtRu anode catalyst, thereby improving DMFC performance. (C) The Electrochemical Society of Japan, All rights reserved.