- Sodium hydrazinidoborane: A chemical hydrogen-storage material
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Herein, we present the successful synthesis and full characterization (by 11B magic-angle-spinning nuclear magnetic resonance spectroscopy, infrared spectroscopy, powder X-ray diffraction) of sodium hydrazinidoborane (NaN2H3BH3, with a hydrogen content of 8.85 wt%), a new material for chemical hydrogen storage. Using lab-prepared pure hydrazine borane (N2H4BH3) and commercial sodium hydride as precursors, sodium hydrazinidoborane was synthesized by ball-milling at low temperature (-30 °C) under an argon atmosphere. Its thermal stability was assessed by thermogravimetric analysis and differential scanning calorimetry. It was found that under heating sodium hydrazinidoborane starts to liberate hydrogen below 608C. Within the range of 60-150 °C, the overall mass loss is as high as 7.6 wt%. Relative to the parent N 2H4BH3, sodium hydrazinidoborane shows improved dehydrogenation properties, further confirmed by dehydrogenation experiments under prolonged heating at constant temperatures of 80, 90, 95, 100, and 110°C. Hence, sodium hydrazinidoborane appears to be more suitable for chemical hydrogen storage than N2H4BH3.
- Moury, Romain,Demirci, Umit B.,Ichikawa, Takayuki,Filinchuk, Yaroslav,Chiriac, Rodica,Van Der Lee, Arie,Miele, Philippe
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- Complete Dehydrogenation of Hydrazine Borane on Manganese Oxide Nanorod-Supported Ni&at;Ir Core-Shell Nanoparticles
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Hydrazine borane (HB; N2H4BH3) has been considered to be one of the most promising solid chemical hydrogen storage materials owing to its high hydrogen capacity and stability under ambient conditions. Despite that, the high purity of hydrogen production from the complete dehydrogenation of HB stands as a major problem that needs to be solved for the convenient use of HB in on-demand hydrogen production systems. In this study, we describe the development of a new catalytic material comprised of bimetallic Ni&at;Ir core-shell nanoparticles (NPs) supported on OMS-2-type manganese oxide octahedral molecular sieve nanorods (Ni&at;Ir/OMS-2), which can reproducibly be prepared by following a synthesis protocol including (i) the oleylamine-mediated preparation of colloidal Ni&at;Ir NPs and (ii) wet impregnation of these ex situ synthesized Ni&at;Ir NPs onto the OMS-2 surface. The characterization of Ni&at;Ir/OMS-2 has been done by using various spectroscopic and visualization techniques, and their results have revealed the formation of well-dispersed Ni&at;Ir core-shell NPs on the surface of OMS-2. The catalytic employment of Ni&at;Ir/OMS-2 in the dehydrogenation of HB showed that Ni0.22&at;Ir0.78/OMS-2 exhibited high dehydrogenation selectivity (>99percent) at complete conversion with a turnover frequency (TOF) value of 2590 h-1 at 323 K, which is the highest activity value among all reported catalysts for the complete dehydrogenation of HB. Furthermore, the Ni0.22&at;Ir0.78/OMS-2 catalyst enables facile recovery and high stability against agglomeration and leaching, which make it a reusable catalyst in the complete dehydrogenation of HB. The studies reported herein also include the collection of wealthy kinetic data to determine the activation parameters for Ni0.22&at;Ir0.78/OMS-2-catalyzed dehydrogenation of HB.
- Bulut, Ahmet,Kanberoglu, Gulsah Saydan,Kaya, Murat,Top, Tuba,Yurderi, Mehmet,Zahmakiran, Mehmet
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- Spectroscopic Studies on Hydrazine-Boranes, Key Compounds for Chemical Hydrogen Storage
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Hydrazine-boranes (H2NNH2·BH3 and H3B·NH2NH2·BH3) have been proposed for the storage of hydrogen, but these compounds have not created scope for extensive research works as ammonia- A nd methylamine-boranes have made these last decades. In the exciting research devoted to energy storage with environmentally friendly processes, hydrazine-borane, hydrazine-bisborane, and their simply substituted derivatives could provide a satisfactory response for hydrogen production and recyclability of the formed products. To date, knowledge of the physical and chemical properties of these compounds is still scarce. In this paper, the electronic structure of various hydrazine-boranes complexes is studied by ultraviolet-photoelectron spectroscopy (UV-PES), which is the experimental technique giving direct access to the energy of occupied molecular orbitals. Thus, UV-PE spectra were registered and first ionization energies were determined. Understanding of different types of interactions between nitrogen lone pairs and their variations by complexation has been our essential goal in these studies. In particular, clear stabilization of all molecular orbital energies is noted when complexation with borane takes place. Evolution of the σBN bond during the hydrogen release process upon thermal activation has also been studied experimentally by UV-PES and supported by quantum chemical calculations.
- Escalona, Javier Torres,Guillemin, Jean-Claude,Darrigan, Clovis,Chrostowska, Anna
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p. 6003 - 6015
(2019/08/06)
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- Unraveling the mechanical behaviour of hydrazine borane (NH2-NH2-BH3)
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Crystalline B-N-H compounds of low molecular weight have been intensively investigated over the past two decades owing to their promises for chemical hydrogen storage. Hydrazine borane NH2-NH2-BH3 is one of the most recent examples of this family of materials. In the present work, we explored its structural behaviour under mechanical stimulus by synchrotron high pressure X-ray diffraction. It has been evidenced that hydrazine borane shows a gradual pressure-induced decrease of its unit cell dimension and the process is reversible when the applied pressure is released. The compressibility of this material was established to be relatively low (high bulk modulus) and highly anisotropic. As revealed by molecular simulations based on Density Functional Theory calculations, the mechanical behaviour of NH2-NH2-BH3 was correlated to the pressure-induced changes of its crystal structure in terms of intra- and intermolecular bond lengths and angles parameters.
- Yot, Pascal G.,Yadav, Vibhav,Ould Amara, Salem,Itiè, Jean-Paul,Demirci, Umit B.,Maurin, Guillaume
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p. 2845 - 2850
(2018/02/07)
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- Controlled Synthesis of MOF-Encapsulated NiPt Nanoparticles toward Efficient and Complete Hydrogen Evolution from Hydrazine Borane and Hydrazine
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The catalytic dehydrogenation of hydrazine borane (N2H4BH3) and hydrous hydrazine (N2H4·H2O) for H2 evolution is considered as two of the pivotal reactions for the implementation of the hydrogen-based economy. A reduction rate controlled strategy is successfully applied for the encapsulating of uniform tiny NiPt alloy nanoclusters within the opening porous channels of MOFs in this work. The resultant Ni0.9Pt0.1/MOF core-shell composite with a low Pt content exerted exceedingly high activity and durability for complete H2 evolution (100% hydrogen selectivity) from alkaline N2H4BH3 and N2H4·H2O solution. The features of small NiPt alloy NPs, strong synergistic effect between NiPt alloy NPs and the MOF, and open pore structure for freely mass transfer made NiPt/MIL-101 an excellent catalyst for highly efficient H2 evolution from N2H4BH3 or N2H4·H2O.
- Zhang, Zhujun,Zhang, Shiliang,Yao, Qilu,Chen, Xiangshu,Lu, Zhang-Hui
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supporting information
p. 11938 - 11945
(2017/10/10)
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- CeOx-modified RhNi nanoparticles grown on rGO as highly efficient catalysts for complete hydrogen generation from hydrazine borane and hydrazine
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CeOx-modified RhNi nanoparticles (NPs) grown on reduced graphene oxide (rGO) (RhNi@CeOx/rGO) have been facilely prepared and successfully used as highly efficient catalysts for the rapid and complete hydrogen generation from aqueous solution of hydrazine borane (N2H4BH3) and hydrazine (N2H4), respectively. It was found that the CeOx-doped RhNi NPs with a size of around 3.5 nm were highly dispersed on rGO nanosheets. Among all the catalysts investigated, the optimized catalyst Rh0.8Ni0.2@CeOx/rGO with a CeOx content of 13.9 mol% exhibited the highest catalytic performance. The total turnover frequency (TOF) of Rh0.8Ni0.2@CeOx/rGO for hydrogen generation from N2H4BH3 reached 666.7 h-1 (molH2 mol(Rh+Ni)-1 h-1) at 323 K, which was among the highest of all the catalysts reported to date for this reaction, 10-fold higher than that of the benchmark catalyst Rh0.8Ni0.2, and 3-fold higher than that of Rh0.8Ni0.2 with a CeOx dopant (Rh0.8Ni0.2@CeOx) and a rGO support (Rh0.8Ni0.2/rGO). Even at room temperature, Rh0.8Ni0.2@CeOx/rGO can achieve a complete hydrogen generation from N2H4BH3 and N2H4 with a TOF value of 111.2 and 36.4 h-1. This excellent catalytic performance might be attributed to the synergistic structural and electronic effects of the RhNi NPs, CeOx dopant, and rGO support. Moreover, this general method can be easily extended to facile synthesis of other metal/rGO systems with the doping of rare-earth oxides for more applications.
- Zhang, Zhujun,Lu, Zhang-Hui,Tan, Hongliang,Chen, Xiangshu,Yao, Qilu
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supporting information
p. 23520 - 23529
(2015/11/28)
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