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Article Citation - WoS: 9Citation - Scopus: 10Investigation of the Performance of High-Temperature Electrochemical Hydrogen Purification From Reformate Gases(Wiley, 2022) Durmus, Gizem Nur Bulanik; Durmuş, Gizem Nur Bulanık; Colpan, C. Ozgur; Devrim, Yilser; Devrim, Yılser; Durmuş, Gizem Nur Bulanık; Devrim, Yılser; Mechanical Engineering; Energy Systems Engineering; Mechanical Engineering; Energy Systems EngineeringIn the present work, the purification of hydrogen from a hydrogen/carbon dioxide/carbon monoxide (H-2:CO2:CO) mixture by a high-temperature electrochemical purification (HT-ECHP) system is examined. Electrochemical H-2 purification experiments were carried out in the temperature range of 140-180 degrees C. The effects of the molar ratio of the gases in the mixture (H-2:CO2:CO-75:25:0, H-2:CO2:CO-72:26:2,0 H-2:CO2:CO-75:22:3, H-2:CO2:CO-75:20:5, H-2:CO2:CO-97:0:3, H-2:CO2:CO-95:0:5) and the operating temperature on the electrochemical H-2 separation were investigated. As a result of the electrochemical H-2 purification experiments, it was determined that the operating temperature is the most important parameter affecting the performance. According to the results obtained, H-2 purity of 99.999% was achieved at 160 degrees C with the reformate gas mixture containing 72% H-2, 26% CO2, and 2% CO by volume. According to the polarization curves of the gas mixtures containing CO, high current densities at low voltage were reached at 180 degrees C, and it was observed that the performance increased as the temperature increased, whereas the gas mixture without CO gave the best performance at 160 degrees C.Article Citation - WoS: 26Citation - Scopus: 27Performance of an Ht-Pemfc Having a Catalyst With Graphene and Multiwalled Carbon Nanotube Support(Wiley, 2019) Alpaydin, Guvenc Umur; Devrim, Yilser; Colpan, C. OzgurIn this study, the effect of multiwalled carbon nanotube and graphene nanoplatelet-based catalyst supports on the performance of reformate gas-fed polybenzimidazole (PBI)-based high-temperature proton exchange membrane fuel cell (HT-PEMFC) was investigated. In addition, the effect of several microwave conditions on the performance of the Pt-Ru/multiwalled carbon nanotube (MWCNT)-graphene nanoplatelet (GNP) catalyst was assessed. Through X-ray diffraction, thermal gravimetric analysis, transmission electron microscopy, scanning electron microscopy, and energy dispersive spectroscopy, the catalysts' chemical structure and morphology were characterized. Cyclic voltammetry analysis was used for the electrochemical characterization of catalysts through an electrochemical cell with three electrodes connected to a potentiostat. The results showed that the best performing catalyst is the catalyst produced using 800-W power for 40 seconds. The electrochemically active surface area values of this catalyst ranged from 54 to 45 m(2)/g. Single-cell performance tests of the HT-PEMFC were then carried out. In these tests, reformate gas mixture, consisting of H-2, CO2, and CO, was fed to the anode side at 160 degrees C without humidification. These tests for the best performing catalyst yielded peak power density of 0.280 W/cm(2) and current density (at 0.6 V) of 0.180 A/cm(2) in the H-2/air environment and peak power density of 0.266 W/cm(2) and current density (at 0.6 V) of 0.171 A/cm(2) in the reformate gas/air environment. As a result of the experiments, it was found that Pt-Ru/MWCNT-GNP hybrid material is a suitable catalyst for HT-PEMFC.
