2 results
Search Results
Now showing 1 - 2 of 2
Conference Object Citation - WoS: 82Citation - Scopus: 92Graphene Based Catalyst Supports for High Temperature Pem Fuel Cell Application(Pergamon-elsevier Science Ltd, 2018) Devrim, Yilser; Arica, Elif Damla; Albostan, AyhanIn this study, the effect of graphene nanoplatelet (GNP) and graphene oxide (GO) based carbon supports on polybenzimidazole (PBI) based high temperature proton exchange membrane fuel cells (HT-PEMFCs) performances were investigated. Pt/GNP and Pt/GO catalysts were synthesized by microwave assisted chemical reduction support. X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Brauner, Emmet and Teller (BET) analysis and high resolution transmission electron microscopy (HRTEM) were used to investigate the microstructure and morphology of the as-prepared catalysts. The electrochemical surface area (ESA) was studied by cyclic voltammetry (CV). The results showed deposition of smaller Pt nanoparticles with uniform distribution and higher ECSA for Pt/GNP compared to Pt/GO. The Pt/GNP and Pt/GO catalysts were tested in 25 cm(2) active area single HT-PEMFC with H-2/air at 160 degrees C without humidification. Performance evaluation in HT-PEMFC shows current densities of 0.28, 0.17 and 0.22 A/cm(2) for the Pt/GNP, Pt/C and Pt/GO catalysts based MEAs at 160 degrees C, respectively. The maximum power density was obtained for MEA prepared by Pt/GNP catalyst with H-2/Air dry reactant gases as 0.34, 0.40 and 0.46 W/cm(2) at 160 degrees C, 175 degrees C and 190 degrees C, respectively. Graphene based catalyst supports exhibits an enhanced HT-PEMFC performance in both low and high current density regions. The results indicate the graphene catalyst support could be utilized as the catalyst support for HT-PEMFC application. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Effects of Graphene Transfer and Thermal Annealing on Anticorrosive Properties of Stainless Steel(Amer Scientific Publishers, 2017) Oh, Jeong Hyeon; Han, Sangmok; Kim, Tae-Yoon; Park, Jongee; Ozturk, Abdullah; Kim, Soo YoungStainless steel (STS) films were annealed in a thermal quartz tube and covered with graphene to improve their anticorrosive properties. Graphene was synthesized via the chemical vapor deposition method and transferred onto the surface of the STS film by the layer-by-layer approach. The structure of the STS film changed from alpha-Fe to gamma-Fe after annealing at 700 C for 1 h, resulting in an increase of 82.72% in the inhibition efficiency. However, one-layer graphene acted as a conductive pathway and therefore deteriorated the anticorrosive properties of the STS film. To overcome this problem, graphene was transferred layer by layer onto the STS film. It was found that transfer of three layers of graphene onto the STS film resulted in a 91.57% increase in the inhibition efficiency. Therefore, thermal annealing and transfer of multilayer graphene are considered to be effective in enhancing the anticorrosive properties of STS films.
