(Digital Presentation) Effect of Iron Doping on Oxygen Reduction Activity of Zirconium Oxides Containing Carbon and Nitrogen Using Pyrazine Carboxylic Acid As Platinum Alternative Cathodes for PEFC

Abstract

Fe-added zirconium oxide catalysts were synthesized by using pyrazine carboxylic acid to enhance oxygen reduction reaction (ORR) activity in acidic media. Fe-added zirconium oxide with a Fe/Zr atomic ratio of 0.1 showed highest ORR onset potential, 0.917 V vs. reversible hydrogen electrode among other zirconium oxide-based catalysts including the previous study. High quality active sites for ORR might be created by substitution of Zr4+ by Fe3+ in ZrO2 monoclinic structure. Although no use of carbon support caused a large particle size of zirconium oxides approximately 20~200 nm, the ORR activity drastically increased because of the creation of high quality active sites. We found that a positive correlation between a ratio of ZrO2 monoclinic structure and ORR activity. As a result, the use of pyrazine carboxylic acid was useful to create high quality active sites and a suitable electron conduction path.