Hyun, Kyuhwan Lee, Jin Hee Yoon, Chang Won Cho, Yong-Hun Kim, Lae-Hyun Kwon, Yongchai 2024-01-20T10:02:31Z 2024-01-20T10:02:31Z 2021-09-05 2014-04 0379-6779 https://pubs.kist.re.kr/handle/201004/126916 Sluggish oxygen reduction reaction (ORR) kinetics and excessive usage of expensive platinum (Pt) catalyst are two main roadblocks hampering more popularity of proton exchange membrane fuel cells. As an alternative way to alleviate these problems, we develop a new ORR catalyst. The new catalyst (PtNi/PPyCNT) is obtained by (1) addition of Ni to Pt to form metal alloy (PtNi) and (2) employment of polypyrrole (PPy) to carbon nanotube (CNT) (PPy-CNT). Optimal thickness of PPy is electrochemically determined while PtNi is well alloyed by the use of sodium borohydride (NaBH4). In experimental evaluations, despite less Pt portion (31 wt %) in PtNi/PPy-CNT than that in Pt/C (40 wt %), its ORR activities (limiting current density, half-wave potential, transferred electron number and H2O2%) are compatible with those in Pt/C with better catalytic stability. It turns out that (i) PtNi-N networks cause increase in oxygen adsorption and weakening of O-O bond, followed by promotion of desirable ORR and (ii) C-N networks formed as pyridinic N improve the electron-donating capability and lead to increase in ORR activity. (C) 2014 Elsevier BM. All rights reserved. English ELSEVIER SCIENCE SA METAL-FREE ELECTROCATALYSTS CARBON NANOTUBES GRAPHENE PERFORMANCE POLYMER CATHODE Improvement in oxygen reduction activity of polypyrrole-coated PtNi alloy catalyst prepared for proton exchange membrane fuel cells Article 10.1016/j.synthmet.2014.02.003 1 SYNTHETIC METALS, v.190, pp.48 - 55 SYNTHETIC METALS 190 48 55 scie scopus 000334483800009 2-s2.0-84894609328 Materials Science, Multidisciplinary Physics, Condensed Matter Polymer Science Materials Science Physics Polymer Science Article METAL-FREE ELECTROCATALYSTS CARBON NANOTUBES GRAPHENE PERFORMANCE POLYMER CATHODE Proton exchange membrane fuel cell Polypyrrole Transition metal porphyrin structure Pyridinic N ORR activity