A PEFC Parametric Study: CO Tolerance As a Function of Operating Conditions

Abstract

: One of the current barriers listed in the Safety Codes and Standards section of the Fuel Cell Technologies Office Multiyear Research, Development, and Demonstration Plan is: ‘insufficient technical data to revise standards’ [1]. More specifically, SAE J2719 and ISO-14687-2 are two recently developed standards for gaseous hydrogen fuel specifications whose revisions are being planned [2,3]. Both standards are applicable for fuel cell vehicles and each governs contaminants and their maximum allowable concentration in H2. Of the contaminants listed in these fuel specifications, we focus our efforts on carbon monoxide (CO), whose allowable level is 200 parts per billion (ppb). In our Polymer Electrolyte Fuel Cell (PEFC) parametric study, we utilized 25cm2 Membrane Electrode Assemblies (MEAs) with 2015 DOE target loadings for platinum (0.15mg Pt/cm2). While it is virtually impossible to test the impact of CO using all of the possible testing conditions, we have systematically formed a set of experiments (Table 1) that encompasses a broad spectrum of Fuel Cell (FC) operating parameters. For each experiment, we fixed the cell temperature at 80oC and operated the FC at 1 A/cm2 with H2 and air stoichiometric flows equivalent to 83% and 50% utilization, respectively. The table reflects the parameters we vowed such as: relative humidity (32, 50, and 100% RH), back pressure (ambient, 150kPa, and 275kPa) and CO concentration (0.2, 0.5, 1.0ppm). The CO dosage remained constant throughout the experiments conducted in this study. In this presentation we will provide data to modelers for enhancing their predictive capabilities in order to help the FC community deduce the CO impact at other operating condition.