Performance Enhancement of Polymer Electrolyte Membrane Fuel Cells with Cerium Oxide Interlayers Prepared by Aerosol-Assisted Chemical Vapor Deposition

초록

In this study, the performance and durability of a Pt/CeO x catalyst membrane electrode assembly (MEA)fabricatedby chemical vapor deposition and sputtering using aerosols were investigatedfor use in a polymer electrolyte membrane fuel cell (PEMFC). The costburden of Pt-based catalysts and the degradation of performance anddurability owing to corrosion of the carbon support under certainconditions limit the commercialization of PEMFCs. To solve these problems,the development of Pt alloy catalysts (Pt-Co, Pt-Ni,and Pt-Fe), Pt-based core-shell catalysts (Pt-TiO2 and Pt-CeO2), Pt bimetallic catalysts (Pt-Pd,Pt-Ru, and Pt-Sn), and Pt-based nanocomposites (Pt/grapheneand Pt/carbon nanotubes) is being actively researched. Inserting aCeO(x) interlayer between Pt and carbon has three advantages:(i) oxygen supply to Pt due to CeO x interlayer'sability to store oxygen improves catalyst utilization, (ii) improvesthe dispersibility of Pt, and (iii) solves the problem of performance and durability degradationby preventing the formation of reactive intermediates. For the depositionof ceria, the aerosol-assisted chemical vapor deposition process,which is performed at atmospheric pressure and can be uniformly depositedover a wide area with spray-based precursor delivery characteristics,was applied. The performance and electrochemical surface area of thePt/CeO x MEA were determined using I-V measurements and cyclic voltammetry,and the durability of the Pt/CeO x MEAwas analyzed using electrochemical impedance spectroscopy and an accelerateddegradation test. As a result, when the Pt/CeO x on the gas diffusion layer (GDL) MEA was used, the performanceimproved by 46% compared to that of Pt on the GDL. By depositing a CeO x interlayeron the PEMFC cathode, performance and durability were improved throughefficient oxygen use.

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