Open AccessExploring Different Synthesis Parameters for the Preparation of Metal-Nitrogen-Carbon Type Oxygen Reduction Catalysts
Author(s) -
Patrick Teppor,
Rutha Jäger,
Eneli Härk,
Silver Sepp,
Mati Kook,
Olga Volobujeva,
Päärn Paiste,
Zdravko Kochovski,
Indrek Tallo,
Enn Lust
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ab7093
Subject(s) - catalysis , cobalt , ball mill , pyrolysis , nitrogen , carbon fibers , chemistry , chemical engineering , silicon carbide , metal , carbon black , inorganic chemistry , oxygen , carbide , materials science , metallurgy , composite material , organic chemistry , composite number , engineering , natural rubber
The influence of various synthesis conditions of a metal-nitrogen-carbon (M-N/C) catalyst material on oxygen reduction reaction (ORR) kinetics is discussed. Seven M-N/C catalysts based on cobalt are obtained by changing various synthesis conditions, such as the mixing environment, pyrolysis gas, and post-treatment. The ORR activity and stability measurements are performed using the classical three-electrode configuration in a 0.1 M HClO 4 solution. The most active and stable ORR catalyst proves to be the material obtained by mixing a cobalt salt, 2,2’-bipyridine, and a high surface area silicon carbide derived carbon together in water and pyrolyzing the mixture in argon. In a fuel cell test, however, a maximum power density value of 135 mW cm −2 is achieved with the catalyst mixed together in a planetary ball-mill at a low catalyst loading of 1.0 ± 0.1 mg cm −2 and at a test cell temperature of 60 o C despite of the fact that preparing the catalyst via dry ball-milling reduces the surface area of the material roughly 40% more than in the case of using a solution-based method. Consequently, mixing the catalyst precursors together without any additional chemicals in a planetary ball-mill instead of in a solution appears to be the most promising choice.