화학공학소재연구정보센터
Applied Catalysis B: Environmental, Vol.217, 144-153, 2017
Trapped metallic cobalt nanoparticles in doped porous graphite: An electrocatalyst that gets better over reaction time
Hybrid materials synthesis is a pathway to integrating unstable inorganic phases in a protective matrix, as an approach to phase stabilization in harsh environments and to use the unique catalytic properties of such metastable phases. Here, we show a polymer precursor method to synthesize nitrogen-doped carbon nanomaterials from melamine-formaldehyde resin with Co2+ ions coordinated in the precursor material. Co2+ ions are reduced during the pyrolysis process to form metallic nanoparticles. Nitrogen doped carbon nanotubes, with high nitrogen content, are obtained at pyrolysis temperature of 800 degrees C or 900 degrees C. When lower temperature is used (i.e. 700 degrees C), porous amorphous carbon is obtained. At the highest temperature used (1000 degrees C), carbon matrix with low nitrogen content is produced, having porous graphitic carbon structure. Graphitic carbon structure and metallic cobalt showed impressive catalytic activity toward water electrooxidation reaction, similar to benchmark catalysts for OER. The stability studies of the electrocatalyst showed an extraordinary 52% current density improvement in the first 8 h of OER, and then a very stable pattern is verified. After 12 h of applied potential, Tafel slope decreases to 57 mV dec(-1), which is characteristic of very fast surface kinetics, and therefore it is a promising material to become a reliable alternative to anode manufacture for OER. (C) 2017 Elsevier B.V. All rights reserved.