Van Yüzüncü Yıl Üniversitesi

Permanent URI for this communityhttps://hdl.handle.net/20.500.14720/1

Browse

Now showing 1 - 7 of 7

Eco-Friendly Synthesis of Carboxymethyl Cellulose-Stabilized Ru0.57co0.43 Nanoclusters as Extremely Efficient and Durable Catalysts for Hydrolytic Dehydrogenation of Methylamine Borane
(Amer Chemical Soc, 2020) Abay, Bayram; Rakap, Murat
Herein, we report the first ever eco-friendly and easy synthesis of carboxymethyl cellulose-stabilized RuCo nanoclusters (Ru0.57Co0.43@CMC) and their use as highly efficient and durable catalysts to produce hydrogen from hydrolytic dehydrogenation of methylamine borane (MeAB). Ru0.57Co0.43@CMC nanoclusters are easily synthesized from synchronous chemical reduction of suitable water-soluble cobalt and ruthenium salts by sodium borohydride. They are identified by some advanced methods including ultraviolet-visible spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. All related kinetic studies show that Ru0.57Co0.43@CMC nanoclusters are extremely efficient, relatively cost-saver, and durable catalysts in hydrolytic dehydrogenation of MeAB at very low temperatures. They provided the highest ever initial turnover frequency value of 327.1 min(-1) and also the apparent activation energy of 49.7 kJ/mol for the hydrolytic dehydrogenation of MeAB.
Hydrogen Generation From Ammonia Borane by Niru Nanoparticles Catalysts
(Taylor & Francis inc, 2021) Abay, Bayram; Rakap, Murat
The preparation, characterization and catalytic test of alloy type poly(N-vinyl-2-pyrrolidone)-protected nickel-ruthenium nanoparticles (3.8 +/- 1.6 nm) (Ni-Ru@PVP) to liberate hydrogen from ammonia borane via hydrolysis have been reported in the present study. Ni-Ru@PVP nanoparticles have easily been synthesized by simultaneous reduction of suitable water-soluble nickel and ruthenium salts in the mixture of water/ethanol by a modified method of alcohol reduction with PVP as both reducing agent and stabilizer. They have been characterized by ultraviolet-visible spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. They have been detected to be highly efficient and durable catalysts to liberate hydrogen from ammonia borane via hydrolysis under ambient conditions. Among prepared catalysts, Ni0.5Ru0.5@PVP nanoparticles provided mean turnover frequency (TOF) of 300 min(-1)and activation energy of 46.8 +/- 1.2 kJ mol(-1)in this hydrolysis reaction.
Hydrogen Generation From Hydrolytic Dehydrogenation of Hydrazine Borane by Poly(n-Vinyl Palladium Nanoparticles
(Elsevier Science Bv, 2015) Tunc, Nihat; Abay, Bayram; Rakap, Murat
Poly(N-vinyl-2-pyrrolidone)-stabilized palladium nanoparticles (3.5 +/- 1.0 nm) are efficient catalysts in the hydrolytic dehydrogenation of hydrazine borane to give hydrogen gas. The catalyst, prepared by reduction of palladium metal ion in ethanol/water mixture by an alcohol reduction method, is durable and efficient catalysts for hydrogen generation from the hydrolytic dehydrogenation of hydrazine borane even at very low concentrations and temperature, providing an average turnover frequency of 42.9 min(-1) with an activation energy of 54.5 +/- 2 kJ mol(-1) for the hydrolytic dehydrogenation of hydrazine borane. (C) 2015 Elsevier B.V. All rights reserved.
Hydrogen Liberation From Ethylenediamine Bisborane Hydrolysis by Platinum Nanoparticles
(Pergamon-elsevier Science Ltd, 2022) Abay, Bayram; Rakap, Murat
The synthesis and characterization of poly (N-vinyl-2-pyrrolidone)-protected platinum (Pt/ PVP) nanoparticles with their employment as highly effective catalysts to liberate hydrogen from hydrolysis of ethylenediamine bisborane (EDAB) is reported here. The nanoparticles are easily synthesized from the reduction of platinum cations in ethanol/water mixture under refluxing. They remain stable for months without any sign of precipitation. They are characterized by fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Pt/PVP nanoparticles provide the greatest TOF value (166.7 min(-1)) reported so far for the hydrolysis of EDAB. Their activation energy is 81.9 kJ mol(-1) in the same reaction. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Hydrolysis of Ammonia Borane and Hydrazine Borane by Poly(n-Vinyl Copd Nanoparticles for Chemical Hydrogen Storage
(Tubitak Scientific & Technological Research Council Turkey, 2017) Rakap, Murat; Abay, Bayram; Tunc, Nihat
For the first time the synthesis of poly(N-vinyl-2-pyrrolidone)-stabilized cobalt-palladium nanoparticles by an easy method, their characterization, and their use as active catalysts for hydrogen release from hydrolysis of ammonia borane and hydrazine borane is reported here. The catalyst is prepared by simultaneous reduction of suitable cobalt and palladium ions by sodium borohydride in the presence of poly(N-vinyl-2-pyrrolidone) as a stabilizer. They are characterized by UV-Vis spectroscopy, TEM analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. They provide average turnover frequencies of 30 min(-1) and 45 min(-1) in the hydrolysis of ammonia borane and hydrazine borane. They also provide activation energies of 48.6 +/- 2 and 50.6 +/- 2 kJ mol(-1) in the hydrolysis of ammonia borane and hydrazine borane.
Rh-M (M: Co, Cu, and Fe) Nanoclusters as Highly Efficient and Durable Catalysts for the Methanolysis of Ammonia Borane
(Royal Soc Chemistry, 2020) Abay, Bayram; Rakap, Murat
Herein, we report the preparation, characterization, and employment of hydroxyapatite-supported rhodium-based Rh-M (RhCo, RhCu, and RhFe) nanoclusters as cost-effective, highly efficient and reusable catalysts for hydrogen evolution from ammonia borane methanolysis. Rh-M@HA nanoclusters are formed by in situ reduction of hydroxyapatite-supported related metal cations during ammonia borane methanolysis after ion-exchange. The Rh-M@HA nanoclusters are easily obtained as very stable solids and identified by some advanced analytical techniques like ICP-OES, BET, TEM, XPS, and XRD. After experimental studies, they are found as highly isolable, redispersible, and reusable nanocatalysts to evolve hydrogen from ammonia borane methanolysis under mild conditions. From these three catalysts, the Rh51Co49@HA nanoclusters provide the highest turnover frequency (TOF) value of 193.7 min(-1) while the Rh26Cu74@HA and Rh45Fe55@HA nanoclusters have TOF values of 25.1 and 38.7 min(-1), respectively, in ammonia borane methanolysis at 25 +/- 0.1 degrees C. The apparent activation energies (E-a) of the Rh51Co49@HA, Rh26Cu74@HA, and Rh45Fe55@HA nanoclusters for the same reaction are calculated to be 52.7, 59.7, and 54.1 kJ mol(-1), respectively.
Synthesis and Characterization of Poly (n-Vinyl Nickel-Ruthenium Nanoparticles and Their Use as Catalyst in the Hydrolysis of Ammonia Borane
(2019) Abay, Bayram; Rakap, Dr.y Murat
Bu tez çalışmasında, en önemli katı kimyasal hidrojen depolama malzemelerinden biri olan amonyak borandan hidrojen eldesini katalizleyecek poli(Nvinil-2-pirrolidon) ile kararlılaştırılmış nikel-rutenyum nanokümelerinin sentezi ve tanımlanması gerçekleştirildi. Çalışmada ilk olarak, nikel-rutenyum bimetalik nanokümeleri sulu çözeltide PVP yardımıyla kararlı hale getirilerek sentezlendi. Daha sonra, sentezi gerçekleştirilen bimetalik nanokümeler, XRD, XPS, (HR)TEM ve UVgörünür bölge spektroskopisi gibi ileri analitik yöntemler kullanılarak tanımlandı. Son olarak, başarılı bir şekilde sentezlenen ve tanımlanan nikel-rutenyum bimetalik nanokümelerinin amonyak boranın hidrolinden hidrojen eldesinde kullanılmalarına ilişkin kinetik çalışmalar gerçekleştirildi.

Browse

Browsing Van Yüzüncü Yıl Üniversitesi by Author "Abay, Bayram"