Browsing by Author "Inger, Erk"

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Controllable Hydrogen Generation by Use Smart Hydrogel Reactor Containing Ru Nano Catalyst and Magnetic Iron Nanoparticles
(Elsevier, 2011) Sahiner, Nurettin; Ozay, Ozgur; Inger, Erk; Aktas, Nahit
In this study, p(AMPS) hydrogels are synthesized from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) via a photo polymerization technique. The hydrogels are used as template for metal nanoparticles and magnetic ferrite nanoparticles. and also as a catalysis vessel in the generation of hydrogen from the hydrolysis of NaBH4. Approximately 5 nm Ru (0) and 20-30 nm magnetic ferrite particles are generated in situ inside this p(AMPS) hydrogel network and then used as a catalysis medium in hydrogen production by hydrolysis of sodium boron hydride in a basic medium. With an applied external magnetic field, the hydrogel reactor, containing Ru and ferrite magnetic particles, can be removed from the catalysis medium; providing on-demand generation of hydrogen. The effect of various parameters such as the initial concentration of NaBH4. the amount of catalyst and temperature on the hydrolysis reaction is evaluated. The activation energy for hydrogen production by Ru (0) nanoparticles is found to be 27.5 kJ mol(-1); while the activation enthalpy is 30.4 kJ mol(-1). The hydrogen generation rate in presence of 5 wt% NaOH and 50 mg p(AMPS)-Ru catalyst is 8.2 L H-2 min(-1) g Ru. (C) 2011 Elsevier B.V. All rights reserved.
Hydrogel Assisted Nickel Nanoparticle Synthesis and Their Use in Hydrogen Production From Sodium Boron Hydride
(Pergamon-elsevier Science Ltd, 2011) Ozay, Ozgur; Aktas, Nahit; Inger, Erk; Sahiner, Nurettin
In this study, hydrogels were synthesized from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) via a photo polymerization technique. Approximately 100 nm Ni metal nanoparticles were generated in situ inside these p(AMPS) hydrogel networks and used as a catalyst in hydrogen production by hydrolysis of sodium boron hydride in a basic medium. The effects of several parameters on the hydrolysis reaction such as the amount of catalyst, the initial concentration of NaBH4, and the temperature were investigated. The activation energy, activation enthalpy and activation of entropy for the reaction were calculated as 42.28 kJ mol(-1), 39.59 kJ mol(-1) and -171.67 J mol(-1) K-1, respectively. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
Hydrogen Production From Ammonia Borane Via Hydrogel Template Synthesized Cu, Ni, Co Composites
(Pergamon-elsevier Science Ltd, 2011) Ozay, Ozgur; Inger, Erk; Aktas, Nahit; Sahiner, Nurettin
In situ Co, Cu and Ni nanoparticles were synthesized by chemical reduction of the absorbed Co (II), Cu (II) and Ni (II) ions inside hydrogel networks prepared from 2-acryl-amido-2-methyl-1-propansulfonic acid (AMPS) and were used as a catalyst system in the generation of hydrogen in hydrolysis of ammonia borane (AB). Several parameters affecting the hydrolysis reaction such as the type of the metal, the amount of catalyst, the initial concentration of AB, and temperature, were investigated. The activation energy values in the hydrolysis reaction of AB solution in the presence p(AMPS)-Co, p(AMPS)-Cu and p(AMPS)-Ni catalyst systems were calculated as E-a = 47.7 kJ mol(-1), 48.8 kJ mol(-1) and 52.8 kJ mol(-1), respectively. Thus, the catalytic activity of the metal nanoparticles prepared inside the same hydrogel matrix was found to be Ni < Cu < Co. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
The on Demand Generation of Hydrogen From Co-Ni Bimetallic Nano Catalyst Prepared by Dual Use of Hydrogel: as Template and as Reactor
(Pergamon-elsevier Science Ltd, 2011) Sahiner, Nurettin; Ozay, Ozgur; Aktas, Nahit; Inger, Erk; He, Jibao
We report the preparation of metal nanoparticles in various formulations inside p(2-acrylamido-2-methyl-1-propansulfonic acid; p(AMPS)) hydrogels and their utilization as a catalyst in hydrolysis of NaBH4. The swollen, flexible p(AMPS) network was used for metal ion loading and reduction in situ for the preparation of Co:Ni nanoparticles as bimetallic clusters in various formulation, and Co and Ni bimetallic catalysts as Co + Co, Co + Ni, Ni + Co and Ni + Ni. In addition to utilization of hydrogels as support materials, the p(AMPS)-metal nanoparticle system was used as catalyst to generate hydrogen in the hydrolysis of NaBH4 with very high yield. Various parameters for the hydrolysis reaction were determined and the activation parameters were calculated. For the first time, inclusion of ferrite magnetic particles to control hydrogen generation on demand by using an externally applied magnetic field to remove the hydrogel-catalyst system from the hydrolysis medium is reported. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Superabsorbent Hydrogels for Cobalt Nanoparticle Synthesis and Hydrogen Production From Hydrolysis of Sodium Boron Hydride
(Elsevier Science Bv, 2011) Sahiner, Nurettin; Ozay, Ozgur; Inger, Erk; Aktas, Nahit
Polymeric hydrogels derived from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) were utilized in the preparation of cobalt (Co) metal nanoparticles and used as a composite-catalyst system in hydrogen generation from the hydrolysis of NaBH(4). The embedded Co nanoparticles in the p(AMPS) networks are on the order of 100 nm. It was demonstrated that the p(AMPS)-Co composite system was very effective in the production of hydrogen from alkali aqueous sodium boron hydride solutions. The effect of various parameters such as the initial concentration of NaBH(4). the amount of catalyst and temperature on the hydrolysis reaction was evaluated. The activation energy for hydrogen production by Co particles was found to be 38.14 kJ mol(-1); while the activation enthalpy was 35.46 kJ mol(-1). (C) 2010 Elsevier B.V. All rights reserved.