Synergistic effects of sulfur poisoning and gas diffusion on polarization loss in anodes of solid oxide fuel cells

Abstract

Poisoning effects of sulfur compounds on the performances of solid oxide fuel cells are non‐trivial. However, the synergistic effects of gas diffusion, adsorption, desorption and reaction in anodes are typically neglected. In this work, an analytical model is derived to quantitatively evaluate the poisoning effects of H2S. The results show that sulfur poisoning correlates closely with inefficient gas diffusion for small anode pore size, small porosity/tortuosity, and low working temperatures. As compared with concentration polarization, H2S‐diffusion‐induced activation polarization in thin anodes with a large trueɛnormalτ is detrimental, especially for low‐temperature operations with a high H2S concentration and a low current density. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1127–1134, 2018

Homogenization of current density of PEM fuel cells by in-plane graded distributions of platinum loading and GDL porosity

“…The irregular and anisotropic pores inside the sub-micro/nanoscale porous electrodes affect the Knudsen diffusion of reactant gases [Niu et al 2017]. Moreover, the electrode performance is strongly affected by the pore size, porosity, tortuosity and thickness of the electrode [Niu et al 2018].…”