(490b) Achieving Ultra-High Platinum Utilization Via Optimization of PEM Fuel Cell Cathode Catalyst Layer Microstructure

Abstract: Inefficient usage of expensive platinum catalyst has plagued the design of PEM fuel cells and contributed to the limited production and use of fuel cell systems. This work optimizes the cathode catalyst layer microstructure in two ways: 1) with respect to platinum utilization (measured as kilowatts of electricity produced per gram of platinum) and 2) with respect to current density. A one-dimensional agglomerate model that accounts for liquid water saturation, as initially developed by Nguyen et al. ^{[1, 2]} is modified for use in this study. The cathode catalyst layer microstructure is optimized by manipulating the platinum loading (m_Pt), platinum-to-carbon ratio (Pt|C), catalyst layer thickness (t_cl), and catalyst layer void fraction (). Results are compared to those of Secanell et al. ^[3] in which current density was maximized. It is shown that a twenty-fold increase in platinum utilization can be achieved over existing catalyst layer designs while maintaining power densities above 0.20 W/cm².

References:

[1]        G. Lin, W. He, T. V. Nguyen, Modeling liquid water effects in the gas diffusion and catalyst layers of the cathode of a PEM fuel cell. J. Elec. Soc., 151, A1999-A2006 (2004)

[2]        X. Wang, T. V. Nguyen, Modeling the effects of capillary property of porous media on the performance of the cathode of a PEMFC. J. Elec. Soc., 155, B1085-1092 (2008)

[3]        M. Secanell, K. Karan, A. Suleman, N. Djilali, Multi-variable optimization of PEMFC cathodes using an agglomerate model. Electrochimica Acta, 52, 6318-6337 (2007)