Incorporation of Platinum and Gold Partially Reduced Graphene Oxide into Polymer Electrolyte Membrane Fuel Cells for Inc
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Incorporation of Platinum and Gold Partially Reduced Graphene Oxide into Polymer Electrolyte Membrane Fuel Cells for Increased Output Power and Carbon Monoxide Tolerance Rebecca Isseroff 1, 2, Lee Blackburn 1, Jaymo Kang 3, Hongfei Li 2, Molly Gentleman 2, Miriam Rafailovich 2 1. Lawrence High School, Cedarhurst, NY, USA. 2. Dept. of Materials Science and Engineering, SUNY Stony Brook, Stony Brook, NY, USA. 3. University of California, Berkeley, CA, USA ABSTRACT The Polymer Electrolyte Membrane Fuel Cells (PEMFCs) platinum catalyst’s susceptibility to poisoning by carbon monoxide (CO) reduces its output power. In an effort to diminish poisoning, gold and platinum nanoparticles were incorporated onto partially reduced graphene oxide (Au/Pt-prGO) sheets to reduce both nanoparticle aggregation and the amount of precious metal needed. Applying this material onto the electrodes and Nafion membrane of a PEMFC was hypothesized to increase CO tolerance as well as power output. Aliquots of graphene oxide (GO) were functionalized with platinum and/or gold nanoparticles using a simple desktop synthesis at room temperature. Partial reduction with NaBH4 maintained hydrophilic solubility. Test solutions applied to electrodes and to electrodes + Nafion membrane were first tested in a PEM fuel cell with a pure H2 gas feed and then repeated with a H2 gas feed containing 1000 ppm of CO. Test arrangements averaged doubling the output power of the poisoned control, with the most effective yielding an output power ~250% that of the poisoned control. Additionally, each system’s poisoned output power (PP) was compared to its highest possible output power (PM), with the most effective setup showing no reduction in output power, even with a H2 gas feed containing 1000 ppm of CO. Thus, this offers promise of a simple, cost-effective method of both improving PEMFC power output while reducing or even eliminating CO poisoning at room temperature. INTRODUCTION A major obstacle preventing the Polymer Electrolyte Membrane Fuel Cell (PEMFC) from becoming a viable source of green energy is that the platinum catalysts located in the anode and cathode are extremely susceptible to carbon monoxide (CO) poisoning, which restricts and diminishes the power output of the fuel cell over time. Carbon monoxide is produced from the reverse water gas shift reaction, where CO2, a gas which is present in the ambient atmosphere and thus present in any practical application of the fuel cell, reacts with H2 to produce H2O and CO. Even 25 ppm of CO in a hydrogen gas feed will cut cell voltage by 50% in two hours [1]. To compensate for this, manufacturers increase the amount of platinum catalysts in the electrodes, but this increases the cost. More importantly, PEMFC use requires a 100% pure hydrogen gas feed, which is both considerably expensive and difficult to obtain because of the pure palladium membrane needed during the hydrogen purification process [2]. Even with this, the PEM fuel cell will still be exposed to CO2 in the air in its commercial use, reestablishin
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