Browsing by Author "Atbas, Dilan"

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A Complementary Study on Novel Pdauco Catalysts: Synthesis, Characterization, Direct Formic Acid Fuel Cell Application, and Exergy Analysis
(Pergamon-elsevier Science Ltd, 2018) Kivrak, Hilal; Atbas, Dilan; Alal, Orhan; Cogenli, M. Selim; Bayrakceken, Ayse; Mert, Suha Orcun; Sahin, Ozlem
At present, Pd containing (10-40 wt%) multiwall carbon nanotube (MWCNT) supported Pd monometallic, Pd:Au bimetallic, and PdAuCo trimetallic catalysts are prepared via NaBH4 reduction method to examine their formic acid electrooxidation activities and direct formic acid fuel cell performances (DFAFCs) when used as anode catalysts. These catalysts are characterized by advanced analytical techniques as N-2 adsorption and desorption, XRD, SAXS, SEM-EDX, and TEM. Electronic state of Pd changes by the addition of Au and Co. Moreover, formic acid electrooxidation activities of these catalysts measured by CV indicates that particle size changes in wide range play a major role in the formic acid electrochemical oxidation activity, ascribed the strong structure sensitivity of formic acid electrooxidation reaction. PdAuCo (80:10:10)/MWCNT catalyst displays the most significant current density increase. On the other hand, lower CO stripping peak potential obtained for PdAuCo (80:10:10)/MWCNT catalyst, attributed to the awakening of the Pd-adsorbate bond strength down to its optimum value, which favors higher electrochemical activity. DFAFCs performance tests and exergy analysis reveal that fuel cell performances increase with the addition of Au and Co which can be attributed to synergetic effect. Furthermore, temperature strongly influences the performance of formic acid fuel cell. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Efficient and Rapid Microwave-Assisted Route To Synthesize Pt-Mnox Hydrogen Peroxide Sensor
(Pergamon-elsevier Science Ltd, 2015) Kivrak, Hilal; Alal, Orhan; Atbas, Dilan
A novel electrochemical sensor for the detection of hydrogen peroxide (H2O2) is proposed based on carbon supported Pt-MnOx and Pt nanoparticles, successfully synthesized via microwave irradiation polyol method. The physicochemical properties of the Pt-MnOx and Pt nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Transmission electron microscopy (TEM). Electrochemical properties of the nanoparticles were investigated by cyclic voltammetry (CV) and chronoamperometry (CA). Electrochemical measurements indicate that the oxidation current of H2O2 is linear (R-2=0.998) to its concentration from 2 mu M to 4.0 mM with a detection limit of 0.7 mM (signal/noise = 3). In addition, Pt-MnOx is not affected by ascorbic acid (AA) and uric acid (UA) which are common interfering species. Meanwhile, this Pt-MnOx non-enzymatic H2O2 sensor exhibits excellent selectivity, stability and reproducibility. Thus, this novel non-enzymatic sensor can be found practical applications in H2O2 detection. (C) 2015 Elsevier Ltd. All rights reserved.
Facile and Rapid Synthesis of Microwave Assisted Pd Nanoparticles as Non-Enzymatic Hydrogen Peroxide Sensor
(Esg, 2017) Sahin, Ozlem; Kivrak, Hilal; Kivrak, Arif; Kazici, Hilal Celik; Alal, Orhan; Atbas, Dilan
Carbon supported Pd catalyst was prepared with microwave-assisted polyol method (M-Pd@C) and investigated sensing activity for non-enzymatic hydrogen peroxide (H2O2). Moreover, M-Pd@C and Pd@C catalyst which synthesized via polyol method (P-Pd@C) were compared to each other in terms of electrocatalytic activity. X-ray diffraction (XRD), X-ray photo electron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to investigate structural and morphological properties of these catalysts. Furthermore, electrochemical measurements were performed via cyclic voltammetry (CV), chronoamperometry (CA) techniques. CV results exhibited that M-Pd/C catalyst showed perfect electrocatalytic activity in terms of reduction of H2O2. M-Pd/C catalyst showed a fast response of less than 7 s with a linear range of 5.0x10(-3)-11.0 mM and a relatively low detection limit of 1.2 mu M amperometric response. M-Pd/C catalyst exhibited great selectivity for detecting H2O2 in the existence of several hindering species such as uric acid and ascorbic acid.
Facile and Rapid Synthesis of Microwave Assisted Pd Nanoparticles as Non-Enzymatic Hydrogen Peroxide Sensor (Vol 12, Pg 762, 2017)
(Esg, 2018) Sahin, Ozlem; Kivrak, Hilal; Kivrak, Arif; Kazici, Hilal Celik; Alal, Orhan; Atbas, Dilan