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Article Citation - WoS: 20Citation - Scopus: 26Polybenzimidazole-Modified Carbon Nanotubes as a Support Material for Platinum-Based High-Temperature Proton Exchange Membrane Fuel Cell Electrocatalysts(Pergamon-elsevier Science Ltd, 2021) Eren, Enis Oguzhan; Ozkan, Necati; Devrim, YilserWe fabricate polybenzimidazole (PBI) wrapped carbon nanotubes (MWCNTs) as support material for platinum-based fuel cell electrocatalyst. With the aid of microwave-assisted polyol reduction, we obtain very fine platinum (Pt) nanoparticles on PBI/MWCNT support while reducing the amount of Pt waste during synthesis. Cyclic voltammetry (CV) concludes that Pt-PBI/MWCNT has 43.0 m(2) g(-1) of electrochemically active surface area (ECSA) to catalyze hydrogen oxidation. Furthermore, after the 1000th cycle, Pt-PBI/MWCNT preserves almost 80% of its maximum ECSA, meaning that Pt-PBI/MWCNT is much more durable than the Pt/MWCNT and commercial Pt/C. High-temperature proton exchange membrane fuel cell (HT-PEMFC) performance tests are conducted under H-2/Air conditions at the temperatures ranging from 150 degrees C to 180 degrees C. Nevertheless, tests conclude that the maximum power density values of the Pt-PBI/MWCNT are found inferior to the Pt/C at all temperatures (e.g., 47 vs. 62 mW cm(-2) at 180 degrees C), suggesting that some balance between durability and performance has to be taken into consideration. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 7Development of Non-Noble Co-N Electrocatalyst for High-Temperature Proton Exchange Membrane Fuel Cells(Pergamon-elsevier Science Ltd, 2020) Eren, Enis Oguzhan; Ozkan, Necati; Devrim, YilserThe development of a non-noble Co-N/MWCNT (MWCNT = multi-walled carbon nano tubes) electrocatalyst is achieved through the high-temperature pyrolysis method and successfully characterized by five-step physico-chemical analysis. By utilizing high resolution analytical surface characterization methods, the chemical states of elements are determined, and the presence of Co-N-x sites is confirmed. ORR activity of a Co-N/MWCNT is found to be auspicious. The maximum number of transferred-electron (n) and the diffusion-limiting current density (j(d)) are calculated as 3.95 and 4.53 mA.cm(-2), respectively. The catalyst is further evaluated under a single-cell test station. The test results show that the current and power density values of Co-N/MWCNT are found superior to those of the commercial Pt/C at the 150 degrees C and 160 degrees C (e.g., 57 vs. 69 mW.cm(-2) at 150 degrees C). Due to some stability issues, it is observed that the performance of the Co-N/MWCNT catalyst is slightly decreased while switching the temperature towards 180 degrees C. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
