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Article Citation - WoS: 23Citation - Scopus: 27Nanocrystalline Metal Organic Framework (mil-101) Stabilized Copper Nanoparticles: Highly Efficient Nanocatalyst for the Hydrolytic Dehydrogenation of Methylamine Borane(Elsevier Science Sa, 2018) Baguc, Ismail Burak; Ertas, Ilknur Efecan; Yurderi, Mehmet; Bulut, Ahmet; Zahmakiran, Mehmet; Kaya, MuratThe copper nanoparticles stabilized by nanocrystalline MIL-101 framework (Cu/nano-MIL-101) was reproducibly prepared by following double solvent method combined with liquid phase chemical reduction technique. The characterization of the resulting new material was done by using various analytical techniques including ICP-OES, P-XRD, N-2-adsorption-desorption, XPS, FE-SEM, SEM-EDX, BFTEM and HAADF-STEM; the summation of their results reveals that the formation of well-dispersed and very small sized (0.8 nm) copper nanoparticles within nanocrystalline MIL-101 framework. The catalytic performance of Cu/nano-MIL-101 in terms of activity and stability was tested in the hydrolytic dehydrogenation of methylamine borane (CH3NH2BH3), which has been considered as one of the attractive materials for the efficient chemical hydrogen storage. Cu/nano-MIL-101 catalyzes the hydrolytic dehydrogenation of methylamine borane with high activity (turnover frequency; TOF = 257 mot H-2/mol Cu x h) and conversion ( > 99%) under air at room temperature. Moreover, these nano-MIL-101 framework stabilized copper nanoparticles show great durability against to sintering and leaching, which make Cu/nano-MIL-101 reusable nanocatalyst in the hydrolytic dehydrogenation of methylamine-borane. Cu/nano-MIL-101 nanocatalyst retains 83% of its inherent activity at complete conversion even at 10th recycle in the hydrolytic dehydrogenation of methylamine borane.Article Citation - WoS: 3Citation - Scopus: 3Comparative Performance Study of Acidic Pumice and Basic Pumice Inclusions for Acrylonitrile-Butadiene Composite Filaments(Mary Ann Liebert, inc, 2024) Tayfun, Umit; Tirkes, Seha; Dogan, Mehmet; Tirkes, Suha; Zahmakiran, MehmetThis study aims to evaluate the effective use of porous pumice powder as an additive in acrylonitrile-butadiene-styrene (ABS)-based composite materials. The influence of pumice addition on mechanical, thermomechanical, thermal, and physical properties of ABS filaments was reported. Two types of pumice, namely acidic pumice (AP) and basic pumice (BP), were melt compounded with ABS at loading levels of 5%, 10%, 15%, and 20% by weight using the melt extrusion preparation method. Composites were shaped into dog bone test specimens by the injection molding process. The physical properties of pumice powders were investigated by particle size analysis and X-ray spectroscopy techniques. Mechanical, thermomechanical, thermal, melt flow, and morphological behaviors of ABS/AP and ABS/BP composite filaments were proposed. According to test results, pumice addition led to an increase in the mechanical response of ABS up to a filling ratio of 10%. Further inclusion of pumice caused sharp reduction due to the possible agglomeration of pumice particles. Composites filled with AP yielded remarkably higher mechanical performance in terms of tensile, impact, and hardness strength compared with BP-loaded composites. According to thermal analyses, ABS exhibited higher thermal stability after incorporation of AP and BP. Pumice addition also resulted in raising the glass transition temperature of ABS. Melt flow index (MFI) findings revealed that addition of two types of pumice led to an opposite trend in the melt flow behavior of ABS filaments. Homogeneous dispersion of pumice particles into the ABS matrix when adding low amounts, as well as reduction in dispersion homogeneity with high amounts, of AP and BP was confirmed by scanning electron microscopy (SEM) micrographs.Article Citation - WoS: 80Citation - Scopus: 82Amine Grafted Silica Supported Craupd Alloy Nanoparticles: Superb Heterogeneous Catalysts for the Room Temperature Dehydrogenation of Formic Acid(Royal Soc Chemistry, 2015) Yurderi, Mehmet; Bulut, Ahmet; Caner, Nurdan; Celebi, Metin; Kaya, Murat; Zahmakiran, MehmetHerein we show that a previously unappreciated combination of CrAuPd alloy nanoparticles and amine-grafted silica support facilitates the liberation of CO-free H-2 from dehydrogenation of formic acid with record activity in the absence of any additives at room temperature. Furthermore, their excellent catalytic stability makes them isolable and reusable heterogeneous catalysts in the formic acid dehydrogenation.
