Seda Karaboga

Bio: Seda Karaboga is an academic researcher from Abant Izzet Baysal University. The author has contributed to research in topics: Dehydrogenation & Catalysis. The author has an hindex of 2, co-authored 4 publications receiving 15 citations.

A comparative investigation for identification of N-(4-dimethylamino 3,5-dinitrophenyl)maleimide

Abstract: This study has identified the characteristic behaviors of N-(4-dimethylamino 3,5-dinitrophenyl)maleimide molecule using ab initio Hartree-Fock (HF) and density functional theory (DFT) based on Becke’s three-parameter hybrid exchange functional combined with Lee-Yang-Parr non-local correlation function (HF/B3LYP and DFT/B3LYP) at 6-311G++(d,p) level of theory for the first time. On this basis, the optimized molecular structures, some thermodynamic features at 300 K, function groups of structures, charge distributions-dipole moments, molecular charge transfer regions, spectroscopic characteristic properties, vibrational frequencies, nuclear magnetic resonance chemical shifts of 13C-NMR and 1H-NMR spectra, and corresponding vibrational assignments have been investigated in detail. Comparisons between some experimental findings and theoretical results are performed to test the reliability of the calculation method preferred in the study. The comparison results in high correlation parameters such as R2 =0.976 and R2 =0.985 for the molecular structures and vibrational frequencies in the DFT and HF calculation levels, respectively. Moreover, the obtained vibrational frequencies and calculated results are in good agreement with the experimental data. Additionally, the simulations of highest/lowest occupied/unoccupied molecular orbital (HOMO and LUMO), molecular electrostatic potential (MEP), and electrostatic potential (ESP) maps have shown that there appear strong non-uniform intra-molecular charge distributions (ICT), electron engagements, lone pairs of electrons, π-π* conjugative effects based on the bond weakening, and intermolecular hydrogen bonding in the compound. Correspondingly, the molecule with the electrophilic reactive and nucleophilic regions has been noted to exhibit kinetical chemical stability. All the discussions have been confirmed by means of the findings of optimized molecular structures and vibrational frequencies belonging to the molecule.

Recent developments of nanocatalyzed liquid-phase hydrogen generation

Abstract: Hydrogen is the most effective and sustainable carrier of clean energy, and liquid-phase hydrogen storage materials with high hydrogen content, reversibility and good dehydrogenation kinetics are promising in view of "hydrogen economy". Efficient, low-cost, safe and selective hydrogen generation from chemical storage materials remains challenging, however. In this Review article, an overview of the recent achievements is provided, addressing the topic of nanocatalysis of hydrogen production from liquid-phase hydrogen storage materials including metal-boron hydrides, borane-nitrogen compounds, and liquid organic hydrides. The state-of-the-art catalysts range from high-performance nanocatalysts based on noble and non-noble metal nanoparticles (NPs) to emerging single-atom catalysts. Key aspects that are discussed include insights into the dehydrogenation mechanisms, regenerations from the spent liquid chemical hydrides, and tandem reactions using the in situ generated hydrogen. Finally, challenges, perspectives, and research directions for this area are envisaged.

The Hydrogen-Storage Challenge: Nanoparticles for Metal-Catalyzed Ammonia Borane Dehydrogenation.

Abstract: Dihydrogen is one of the sustainable energy vectors envisioned for the future. However, the rapidly reversible and secure storage of large quantities of hydrogen is still a technological and scientific challenge. In this context, this review proposes a recent state-of-the-art on H2 production capacities from the dehydrogenation reaction of ammonia borane (and selected related amine-boranes) as a safer solid source of H2 by hydrolysis (or solvolysis), catalyzed by nanoparticle-based systems. The review groups the results according to the transition metals constituting the catalyst with a mention to their current cost and availability. This includes the noble metals Rh, Pd, Pt, Ru, Ag, as well as cheaper Co, Ni, Cu, and Fe. For each element, the monometallic and polymetallic structures are presented and the performances are described in terms of turnover frequency and recyclability. The structure-property links are highlighted whenever possible. It appears from all these works that the mastery of the preparation of catalysts remains a crucial point both in terms of process, and control and understanding of the electronic structures of the elaborated nanomaterials. A particular effort of the scientific community remains to be made in this multidisciplinary field with major societal stakes.