A general model for air-side proton exchange membrane fuel cell contamination

Abstract

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. This paper presents a general model for air-side feed stream contamination that has the capability of simulating both transient and steady-state performance of a PEM fuel cell in the presence of air-side feed stream impurities. The model is developed based on the oxygen reduction reaction mechanism, contaminant surface adsorption/desorption, and electrochemical reaction kinetics. The model is then applied to the study of air-side toluene contamination. Experimental data for toluene contamination at four current densities (0.2, 0.5, 0.75 and 1.0 A cm −2 ) and three contamination levels (1, 5 and 10 ppm) were used to validate the model. In addition, it is expected that, with parameter adjustment, this model can also be used to predict performance degradation caused by other air impurities such as nitrogen oxides (NO x ) and sulfur oxides (SO x ). Crown

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

“…The adsorbed sulfur species modify the cyclic voltammetric curve of the Pt/VC catalysts. During the first positive sweep from 0 to 1.4 V (CV 1), the electrochemical oxidation of the adsorbed S 0 to SO 4 2− causes a wide anodic peak at 1.15 V. During the first negative sweep from 1.4 to 0 V, reduction peaks appear at about 0.72 V and 0.08 V, which is probably attributed to the reduction of adsorbed oxygen species, protons in the solution and a small amount of sulfur species that are still adsorbed on the surface, respectively. As cycling progresses, the cathodic peaks near 0.72 and 0.08 V increase slowly, implying that sulfur species are removed from the Pt/VC surface.…”

“…At the potential of 0.05 V (vs. RHE), sulfur is in a zero-valence state (S 0 ), which causes an adsorption state of Pt S, or rather, one Pt atom on the surface adsorbing one S 0 atom [8,21]. At high potential (>1.0 V) (vs. RHE), sulfur adsorbed on Pt begins to be oxidized to sulfate (SO 4 2− ), which desorbs from the Pt surface. This process can be described by the following equation [27]:…”

“…Thus the cathode may be exposed to trace undesirable contaminants in the air, such as SO 2 , NO x and organic compounds, which are supposed to be adsorbed by Pt nanoparticles and degrade the performance of PEMFC [1][2][3][4]. Among the ordinary contaminants, sulfur-contained compounds are one of the most severely poisons that affect the performance [3][4][5].…”

“…Thus the cathode may be exposed to trace undesirable contaminants in the air, such as SO 2 , NO x and organic compounds, which are supposed to be adsorbed by Pt nanoparticles and degrade the performance of PEMFC [1][2][3][4]. Among the ordinary contaminants, sulfur-contained compounds are one of the most severely poisons that affect the performance [3][4][5]. Thus a lot of studies have been performed on the poisoning behavior of SO 2 , and exploring the impacts of temperature, humidity, potential and concentration of SO 2 under operating conditions in order to get the recovery strategies [5][6][7][8][9][10][11].…”

Effect of Co2+ on oxygen reduction reaction catalyzed by Pt catalyst, and its implications for fuel cell contamination

“…In the last several years, significant progress has been made in identifying impurity sources and understanding their impacts on fuel cell performance [6][7][8][9][10][11][12][13][14]. For example, the primary impurities in hydrogen fuel are CO, H 2 S, NH 3 , and hydrocarbons deriving mainly from hydrogen-rich reformate gas; the major impurities in the air stream include NO x (NO 2 and NO), SO x (SO 3 and SO 2 ), and CO x (CO 2 and CO), as well as some volatile organic compounds (VOCs).…”