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Article Citation - WoS: 6Citation - Scopus: 7Fabrication and Performance Evaluation of Graphene-Supported Ptru Electrocatalyst for High-Temperature Electrochemical Hydrogen Purification(Pergamon-elsevier Science Ltd, 2023) Bal, Ilay Bilge; Durmus, Gizem Nur Bulanik; Devrim, YilserThe main aim of this study is to investigate the high-temperature electrochemical hydrogen purification (HT-ECHP) performances of graphene nanoplatelet (GNP) support material decorated with platinum (Pt) and platinum-ruthenium (PtRu) nanoparticles prepared by microwave irradiation technique. Prepared catalysts coupled to the phosphoric acid doped polybenzimidazole (PBI) membrane for HT-ECHP application. The structural and electrochemical properties of the catalysts were examined by thermogravimetric analysis (TGA), X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transition electron microscopy (TEM) and cyclic voltammetry (CV) analyses. The characterization results indicate that the catalysts provided the necessary properties for HT-ECHP application. The HT-ECHP performances are investigated with reformate gas mixture containing hydrogen (H2), carbon dioxide (CO2) and carbon monoxide (CO) in the range of 140-180 & DEG;C. The results show that the electrochemical purification performances of the catalysts increase with increasing operating temperature. The highest H2 purification performance is obtained with PtRu/GNP catalyst. The high electrochemical H2 purification performance of the PtRu/GNP catalyst can be attributed to the strong synergistic interactions between Pt and Ru particles decorated on the GNP. These results advocate that the PtRu/GNP catalyst is a hopeful catalyst for HT-ECHP application. & COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Experimental and Modeling Studies of a High-Temperature Electrochemical Hydrogen Compressor(Pergamon-elsevier Science Ltd, 2024) Durmus, Gizem Nur Bulanik; Kuzu, Cemil; Devrim, Yilser; Colpan, C. OzgurSome non-technical factors such as economics and logistics prevent hydrogen (H2) tech-nologies from becoming more widespread in daily life. Today, the prevalence of H2 tech-nologies requires new technological developments. Electrochemical hydrogen compressors (ECHC) are of great interest due to their ability to pressurize and purify in one step. In this study, the electrochemical H2 compression performance of high phosphoric acid (PA) doped poly 2,2-m-phenylene-5,5-benzimidazole (PBI) membrane-based HT-ECHC under high temperature and non-humid conditions was investigated through both an experimental and a numerical approach. The H2 compression capacity of HT-ECHC at different operating voltages was examined by performance tests at 160 degrees C, and it was determined that the electrochemical compression performance increased with increasing operating voltage. It was observed that the current density values also increased with increasing voltage, and it was determined that a current density of 61.2 A was obtained at 1 V. As a result of the tests, H2 was successfully compressed from atmospheric pressure to 60 bar by HT-ECHC without any gas leakage. The results of the developed model were compared with the experimental performance test data, and the variation of molar flow, cell voltage, and cell efficiency over time was examined. It has been determined that the back diffusion from the cathode to the anode in the cell increases with the increasing operating voltage of HT-ECHC and therefore the cell efficiency decreases. It has been evaluated that the developed model and experimental results are in good agreement. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 68Citation - Scopus: 70Composite Membrane by Incorporating Sulfonated Graphene Oxide in Polybenzimidazole for High Temperature Proton Exchange Membrane Fuel Cells(Pergamon-elsevier Science Ltd, 2022) Devrim, Yilser; Durmus, Gizem Nur BulanikThe objective of this work is to examine the polybenzimidazole (PBI)/sulfonated graphene oxide (sGO) membranes as alternative materials for high-temperature proton exchange membrane fuel cell (HT-PEMFC). PBI/sGO composite membranes were characterized by TGA, FTIR, SEM analysis, acid doping&acid leaching tests, mechanical analysis, and proton conductivity measurements. The proton conductivity of composite membranes was considerably enhanced by the existence of sGO filler. The enhancement of these properties is related to the increased content of -SO3H groups in the PBI/sGO composite membrane, increasing the channel availability required for the proton transport. The PBI/sGO membranes were tested in a single HT-PEMFC to evaluate high-temperature fuel cell performance. Amongst the PBI/sGO composite membranes, the membrane containing 5 wt. % GO (PBI/sGO-2) showed the highest HT-PEMFC performance. The maximum power density of 364 mW/cm(2) was yielded by PBI/sGO-2 membrane when operating the cell at 160 degrees C under non humidified conditions. In comparison, a maximum power density of 235 mW/cm(2) was determined by the PBI membrane under the same operating conditions. To investigate the HT-PEMFC stability, long-term stability tests were performed in comparison with the PBI membrane. After a long-term performance test for 200 h, the HT-PEMFC performance loss was obtained as 9% and 13% for PBI/sGO-2 and PBI membranes, respectively. The improved HT-PEMFC performance of PBI/sGO composite membranes suggests that PBI/sGO composites are feasible candidates for HT-PEMFC applications. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 14Citation - Scopus: 14High-Temperature Electrochemical Hydrogen Separation From Reformate Gases Using Pbi/Mof Composite Membrane(Pergamon-elsevier Science Ltd, 2023) Durmus, Gizem Nur Bulanik; Eren, Enis Oguzhan; Devrim, Yilser; Colpan, C. Ozgur; Ozkan, NecatiIn this paper, the high-temperature electrochemical Hydrogen (H2) purification perfor-mance of a polybenzimidazole/UIO-66 metal-organic framework (PBI/UIO-66) membrane is investigated and analyzed at different values of current, temperature, and reformate feed composition. Purification measurements show that a significant reduction in gas impu-rities can be obtained. In the performance tests, three different ratios of reformate gas (RG) (H2:carbon dioxide (CO2):carbon monoxide (CO)) as RG-1= (75:25:0), RG-2= (75:22:3), and RG-3= (95:0:5) were used. The highest purification values were observed at 160 & DEG;C as 99.999%, 99.931%, and 99.708% for RG-1, RG-2, and RG-3, respectively. The obtained results show that an electrochemical H2 purification (ECHP) based on PBI/UIO-66 composite membrane is promising for H2 purification.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
