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Article Citation - WoS: 45Citation - Scopus: 46Carbon Nanotube-Graphene Supported Bimetallic Electrocatalyst for Direct Borohydride Hydrogen Peroxide Fuel Cells(Pergamon-elsevier Science Ltd, 2021) Uzundurukan, Arife; Akca, Elif Seda; Budak, Yagmur; Devrim, YilserAt present study, carbon nanotube-graphene (CNT-G) supported PtAu, Au and Pt catalysts were prepared by microwave-assisted synthesis method to investigate the direct liquid-fed sodium borohydride/hydrogen peroxide (NaBH4/H2O2) fuel cell performance. Prepared catalysts were characterized by TGA, XRD, TEM, ICP-OES, cyclic voltammetry and rotating disc electrode (RDE) voltammetry. The catalysts were tested in a single NaBH4/H2O2 fuel cell with 25 cm(2) active area to evaluate fuel cell performance. The effects of temperature and fuel concentration on fuel cell performance were examined to observed best operating conditions. As a result of direct NaBH4/H2O2 fuel cell experiments, maximum power densities of 139 mW/cm(2), 125 mW/cm(2) and 113 mW/cm(2) were obtained for PtAu/CNT-G, Au/CNT-G and Pt/CNT-G catalysts, respectively. PtAu/CNT-G catalyst showed the enhanced NaBH4/H2O2 fuel cell performance, which was higher than the Pt/CNT-G catalyst and Au/CNT-G catalyst at 50 degrees C. The enhanced NaBH4/H2O2 performance can be attributed to synergistic effects between Pt and Au particles on CNT-G support providing a better catalyst utilization and interaction. These results suggest that the prepared PtAu/CNT-G catalyst is a promising anode catalyst for NaBH4/H2O2 fuel cell application. (c) 2020 Elsevier Ltd. All rights reserved.Article Citation - WoS: 21Citation - Scopus: 21Investigation of Hydrogen Production From Sodium Borohydride by Carbon Nano Tube-Graphene Supported Pdru Bimetallic Catalyst for Pem Fuel Cell Application(Wiley, 2022) Al-Msrhad, Tuqa Majeed Hameed; Devrim, Yilser; Uzundurukan, Arife; Budak, YagmurIn this study, hydrogen (H-2) generation from the hydrolysis of sodium borohydride (NaBH4) catalyzed by bimetallic Palladium-Ruthenium (PdRu) supported on multiwalled carbon nanotube-graphene (MWCNT-GNP) hybrid material is investigated. The effect of various parameters such as temperature, NaBH4 concentration, and catalyst loading and effect of base concentration are examined to observed optimum operating conditions. Experimental results show that the PdRu/MWCNT-GNP bimetallic catalyst has high catalytic activity on NaBH4 hydrolysis reaction. It has been found that PdRu/MWCNT-GNP catalyst shows low activation energy of 22.33 kJ/mol for hydrolysis reaction of NaBH4. The PdRu/MWCNT-GNP catalyst also exhibits H-2 generation rate of 79.2 mmol/min center dot g(cat) at 45 degrees C. It shows good cycle stability in the catalyst reusability test and retained 89% of its initial catalytic activity after fifth use. The high catalytic activity of the PdRu/MWCNT-GNP catalyst makes it promising in H-2 generation from NaBH4 hydrolysis for commercial proton exchange membrane fuel cell (PEMFC) applications.Article Citation - WoS: 7Citation - Scopus: 9Development and Performance Analysis of Polybenzimidazole/Boron Nitride Composite Membranes for High-Temperature Pem Fuel Cells(Wiley, 2022) Hussin, Dedar Emad; Budak, Yagmur; Devrim, YilserIn this research, polybenzimidazole/boron nitride (PBI/BN) based composite membranes have been prepared for high-temperature PEM fuel cell (HT-PEMFC). BN was preferred because of its superior thermal robustness, high chemical stability, non-conductor property, and high plasticizer characteristic. The loading of BN in the composite membrane was studied between 2.5 to 10 wt%. The composite membranes were characterized using TGA, DSC, XRD, SEM, mechanical tests, acid doping/leaching, and proton conductivity measurements. The highest conductivity of 0.260 S/cm was found for PBI/BN-2.5 membrane at 180 degrees C. It has been determined that the PBI/BN-2.5 membrane has higher performance than the PBI membrane according to the HT-PEMFC tests performed with Hydrogen and dry air. The heightened HT-PEMFC performance can be ascribed to interactive effects between BN particles and the PBI polymer matrix. PBI/BN composite membranes show a good perspective in the high-temperature PEMFC applications.Article Citation - WoS: 9Citation - Scopus: 10Evaluation of Hybridsolar-Wind System Based on Methanol Electrolyzer(Wiley, 2020) Budak, Yagmur; Devrim, YilserIn this study, it is aimed to meet the annual electricity and heating needs of a house without interruption with the photovoltaic panel, wind turbine, methanol electrolyzer, and high temperature proton exchange membrane fuel cell system. The system results show that the use of the 2 WT with 18 PV was enough to provide the need of the methanol electrolyzer, which provides requirements of the high temperature proton exchange membrane fuel cell. The produced heat by the fuel cell was used to meet the heat requirement of the house with combined heat and power system. Electrical, thermal and total efficiencies of fuel cell system with combined heat and power were obtained as 38.54%, 51.77% and 90%, respectively. Additionally, the levelized cost of energy of the system was calculated as 0.295 $/kWh with combined heat and power application. The results of this study show that H(2)is useful for long-term energy storage in off-grid energy systems and that the proposed hybrid system may be the basis for future H-2-based alternative energy applications.
