Browsing by Author "Baytar, Orhan"

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Ceo2 Supported Multimetallic Nano Materials as an Efficient Catalyst for Hydrogen Generation From the Hydrolysis of Nabh4
(Pergamon-elsevier Science Ltd, 2020) Izgi, Mehmet Sait; Baytar, Orhan; Sahin, Omer; Kazici, Hilal Celik
Nowadays, there is still no suitable method to store large amounts of energy. Hydrogen can be stored physically in carbon nanotubes or chemically in the form of hydride. In this study, sodium borohydride (NaBH4) was used as the source of hydrogen. However, an inexpensive and useful catalyst (Co-Cr-B/CeO2) was synthesized using the NaBH4 reduction method and its property was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), x-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) measurements. The optimized Co-Cr-B/CeO2 catalyst exhibited an excellent hydrogen generation rate (9182 mLg(metal)(-1) min(-1)) and low activation energy (35.52 kJ mol(-1)). The strong catalytic performance of the Co-Cr-B/CeO2 catalyst is thought to be based on the synergistic effect between multimetallic nanoparticles and the effective charge transfer interactions between the metal and the support material. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Enhanced Electrochemical Double-Layer Capacitive Performance With Co2 Plasma Treatment on Activated Carbon Prepared From Pyrolysis of Pistachio Shells
(Pergamon-elsevier Science Ltd, 2020) Sahin, Omer; Yardim, Yavuz; Baytar, Orhan; Saka, Cafer
This study reports an original approach based on the CO2 plasma treatment on modification of the chemical or physical properties of activated carbon(AC) from the pistachio shells as a waste for application as electrochemical double-layer capacitors(EDLC). In the AC production experiments, impregnation ratio, impregnation pre-treatment temperature, activation temperature and activation time are investigated. In the AC modification experiments with plasma treatment, the effects of plasma gases, plasma power and plasma time are performed. The results of the different conditions indicated that the structural properties of the obtained AC were significantly dependent on the plasma and pyrolysis parameters. The surface properties of the raw AC and plasma-treated AC (PTAC) with X-ray photoelectron spectroscopy (XPS), nitrogen adsorption technique, and scanning electron microscope (SEM) are characterized. Surface area values for the raw AC and PTAC are 768 and 1250 m(2) g(-1), respectively. A change in the peak positions and an increase in the percentage of oxygen of the AC treated with CO2 plasma were obtained from XPS results. After 15 min of CO2 plasma activation, a significant increase in the capacitance of up to about 141% was obtained as a 118.4 F g(-1) compared to 49.98 F g(-1) for untreated AC. The results show that the plasma treatment on the specific surface area and surface functional groups of AC has a significant impact. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
High Hydrogen Production Rate From Potassium Borohydride Hydrolysis With an Efficient Catalyst: Cnt@ru(0)
(Elsevier Science inc, 2022) Keskin, M. Salih; Agirtas, Mehmet Salih; Baytar, Orhan; Izgi, M. Sait; Sahin, Omer; Horoz, Sabit
We describe the production and catalytic activity of a carbon nanotube supported-Ru(0) (CNT@Ru(0)) catalyst. For the first time, the produced CNT@Ru(0) catalyst is used to achieve the greatest hydrogen production rate from potassium borohydride (KBH4) hydrolysis. The produced CNT@ Ru(0) catalyst shows promise in the creation of hydrogen from the degradation of KBH4. The hydrogen generation rate of CNT@Ru(0) is determined to be 86,264.85 mL min(-1) can with a low activation energy of 30.18 kJ mol(-1). CNTs are potential support for distributing metal catalysts, according to the current work. Furthermore, structural, morphological, and elemental characteristics of the produced CNT@Ru(0) catalyst are investigated.
Improvement of Electrochemical Double-Layer Capacitance by Fast and Clean Oxygen Plasma Treatment on Activated Carbon as the Electrode Material From Walnut Shells
(Pergamon-elsevier Science Ltd, 2020) Saka, Cafer; Baytar, Orhan; Yardim, Yavuz; Sahin, Omer
In this study, a simple, fast, and clean oxygen plasma method is presented to increase the surface area of activated carbon from walnut shells (WAC) and to connect functional groups containing oxygen to the carbon sample surface. X-ray photoelectron spectroscopy (XPS), nitrogen adsorption technique, Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), and scanning electron microscope (SEM) analyses to investigate the properties of the WAC and WACP are performed. Cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) measurements are used to investigate the capacitance properties of the supercapacitors. A significant increase in the surface area of the WAC was increased from 22 m(2) g(-1) to 78 m2 g(-1) after oxygen plasma treatment. The specific capacitance was improved from 6.98 F g(-1) to 76.89 F g(-1) at 2.5 mV s(-1). The devices with functionalized electrodes exhibited cyclic stability of 78% after 5000 cycles.
Iodine Adsorption and Electrochemical Double-Layer Capacitor Characteristics of Activated Carbon Prepared From Low-Cost Biomass
(Taylor & Francis inc, 2023) Saka, Cafer; Yardim, Yavuz; Sahin, Omer; Baytar, Orhan
The efficient adsorption application and electric double-layer capacitor material with low-cost biomass-based activated carbon materials have been quite common recently. In this study, chestnut shell-based activated carbons were produced by chemical activation. ZnCl2, H3PO4, and KOH agents were used for chemical activation. The obtained activated carbon, iodine adsorption from aqueous solutions, and its use as an electro capacitor were investigated. The scanning electron microscope, nitrogen adsorption/desorption, and Fourier transform infrared spectroscopy were used for characterization. The values of surface area and iodine adsorption capacity of the chestnut shell-based activated carbon are 1544 m(2) g(-1) and 1525 mg g(-1). As a result, a specific capacitance of 97 Fg(-1) with chestnut shell-based activated carbon was obtained in a 1 M KCl electrolyte for the electrochemical double-layer capacitor. This study shows that activated carbon based on the chestnut shell can be used both as an electrochemical energy storage material and as an adsorbent in iodine adsorption.
Potasyum Borhidrit Hidroliz Reaksiyonu İçin Ni-b-p Katalizörünün Kinetik Özellikleri
(2020) Baytar, Orhan; İzgi, Mehmet Sait; Agırtas, Mehmet Salıh; Şahin, Ömer; Keskin, Mehmet Salih
Bu çalışmada potasyum bor hidrür hidrolizindeki hidrojen üretimi için yüksek performanslı Ni-B-P katalizörüsentezlenmiştir. Bilindiği üzere katalizörler kimya endüstrisinde gerçekleştirilen çoğu reaksiyonlarda kullanılırlar.Burada analitik yöntemle katalizörün, BET, XRD ve SEM analizleri yapılarak katalizörün karakteristik özellikleribelirlendi. Ayrıca Ni2P katalizörünün potasyum bor hidrolizi için; en iyi Ni/P oranı, optimum KOHkonsantrasyonu, KBH4 konsantrasyonu, katalizör miktarı ve kinetiksel parametreler için farklı sıcaklıklardakietkisi incelendi. Katalizörün hidrojen üretim hızının 665 mL/dak*g, en iyi Ni/P oranının 0.184 olarak belirlendi.Ayrıca reaksiyon hız mertebesi n- dereceden 0.25 olarak belirlendi, buna bağlı olarak ta arhenius eşitliğindenaktivasyon enerjisinin değeri 58,528 kJ/mol olarak bulunmuştur.