Destabilization of NH3BH3 by water during hydrothermolysis as a key factor in the high hydrogen evolution rates

Komova, O.V.; Kayl, N.L.; Одегова, Г. В.; Netskina, O.V.; Симагина, В.И.

doi:10.1016/j.ijhydene.2016.07.163

Cited by 16 publications

(11 citation statements)

References 50 publications

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“…The values of Ea obtained in this work indicate that the decrease in AB purity and the accumulation in it of the products of hydrolysis lead to a decrease in the apparent activation energy, which is consistent with the shorter induction period in the isothermal dehydrogenation of the stored AB 79% in Figure 1. Besides, the obtained results are in agreement with the previously published results, showing that the addition to AB of H3BO3 [9,32,33], B2O3 [9] and NH4B5O8⋅4H2O [32] accelerates the process of its thermolysis. It should be noted that in [9], by using the Kissinger, Ozawa-Flynn-Wall, and ASTM (American Society for Testing and Materials) methods, a decrease in Ea has been demonstrated for the thermolysis of a ball-milled mixture of AB with boric acid or boron oxide (50 wt %).…”

Section: Resultssupporting

confidence: 92%

The Effect of Storage-Induced Changes in Ammonia Borane on Hydrogen Release during Its Low-Temperature Thermolysis

et al. 2019

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In this paper, low-temperature solid-state processes of the dehydrogenation of ammonia borane (NH 3 BH 3 , AB) samples of different purity are compared under the conditions of isothermal heating at 100 • C, as well as in the course of thermal analysis which was also carried out at different rates of heating. The composition of boron-containing impurities was studied by attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR) and 11 B magic angle spinning nuclear magnetic resonance ( 11 B MAS NMR). Accumulation in AB of three-and four-coordinated borate anions upon contact of hydride with air moisture is established. The apparent activation energies were calculated from thermal analysis data, and found to decrease from 174 to 163 kJ/mol as the AB purity decreased from 93% to 79%. This showed itself in a shortening of the induction period during the AB thermolysis under isothermal conditions. The prospects of using the thermal analysis for estimating NH 3 BH 3 reactivity are discussed.

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Section: Resultssupporting

confidence: 92%

The Effect of Storage-Induced Changes in Ammonia Borane on Hydrogen Release during Its Low-Temperature Thermolysis

et al. 2019

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“…was readily confirmed by the composition of reaction products using the x-ray diffraction analysis (Mohajeri et al, 2007;Brockman et al, 2010;Chou et al, 2012;Liu et al, 2012;Komova et al, 2016). The NH 3 and B(OH) 3 are being dissolved in water as described by a well known acid-base equilibrium Brockman et al, 2010;Komova et al, 2016).…”

Section: Introductionmentioning

confidence: 90%

“…By measuring the composition of hydrolytic products in the presence of various transition metal-based catalysts (Yao C. F. et al, 2008 ; Rachiero et al, 2011b ; Chou et al, 2012 ; Liu et al, 2012 ; Komova et al, 2016 ), it was confirmed that 1 mole of AB is hydrolyzed to give nearly 1 mole of

ions and 3 moles of H 2 gas. For example, Yao C. F. et al ( 2008 ) have chemically identified that the gaseous product is exclusively H 2 molecules and the soluble product is

ions.…”

Section: Introductionmentioning

confidence: 98%

Formation of a Key Intermediate Complex Species in Catalytic Hydrolysis of NH3BH3 by Bimetal Clusters: Metal-Dihydride and Boron-Multihydroxy

et al. 2020

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The hydrolysis of AB (AB, NH 3 BH 3) with the help of transition metal catalysts has been identified as one of the promising strategies for the dehydrogenation in numerous experiments. Although great progress has been achieved in experiments, evaluation of the B-N bond cleavage channel as well as the hydrogen transfer channel has not been performed to gain a deep understanding of the kinetic route. Based on the density functional theory (DFT) calculation, we presented a clear mechanistic study on the hydrolytic reaction of AB by choosing the smallest NiCu cluster as a catalyst model. Two attacking types of water molecules were considered for the hydrolytic reaction of AB: stepwise and simultaneous adsorption on the catalyst. The Ni and Cu metal atoms play the distinctive roles in catalytic activity, i.e., Ni atom takes reactions for the H 2 O decomposition with the formation of [OH] − group whereas Cu atom takes reactions for the hydride transfer with the formation of metal-dihydride complex. The formation of Cu-dihydride and B-multihydroxy complex is the prerequisite for the effectively hydrolytic dehydrogenation of AB. By analyzing the maximum barrier height of the pathways which determines the kinetic rates, we found that the hydride hydrogen transferring rather than the N-B bond breaking is responsible to the experimentally measured activation energy barrier.

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“…In addition, another parameter of exchange current density (j 0 ) can also be calculated using Equation (5) j 0 = RT n e FR ct (5) where, n e is the number of transferred electrons, and parameters of R, T, and F are already defined by Equation (2). As ascertained by the data (Table 2), without any doubt, the Pt/C sample shows the best HER performance followed by the Ni-P/MoS 2 composites and last by MoS 2 sample.…”

Section: Electrochemical Impedance Spectroscopy (Eis)mentioning

confidence: 99%

“…Until present, carbides [4], borides [5], selenides [6], nitrides [7], phosphides [8], as well as transition metal sulfides [9] have been recommended as HER catalysts. Among them, molybdenum disulfide (MoS 2 ) can be identified as a promising alternative because of the earth-abundant and low-cost advantages, and the passable electrocatalytic property of this material.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen Evolution Reaction Property in Alkaline Solution of Molybdenum Disulfide Modified by Surface Anchor of Nickel–Phosphorus Coating

Jun

Song

Yan

et al. 2017

Metals

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Molybdenum disulfide (MoS 2 ) is unfavorable for practical application in the hydrogen evolution reaction (HER) process due to its inert basal surface, inferior conductivity, and limited amount of active edge sites. For the purpose of enhancing the HER performance of this catalyst, the HER activity of its basal surface should be increased. Herein, three types of nickel-phosphorus (Ni-P) coatings-namely, low phosphorus (LP), medium phosphorus (MP) and high phosphorus (HP) -were anchored onto the surfaces of MoS 2 nanoparticles via an electroless plating process; thus, three Ni-P/MoS 2 composites (Ni-LP/MoS 2 , Ni-MP/MoS 2 , and Ni-HP/MoS 2 ) were fabricated. Crystal structures, morphologies, chemical components, and HER performances of each in an alkaline solution were characterized. Both Ni-LP/MoS 2 and Ni-MP/MoS 2 showed a crystal nature, while the amorphous feature for Ni-HP/MoS 2 was validated. The three Ni-P/MoS 2 composites exhibited a higher HER activity than the pure MoS 2 . The HER performance of the Ni-MP/MoS 2 composite was more outstanding than those of other two composites, which could be attributed to the presence of metastable nickel phosphides, and the excellent conductivity of Ni-MP coating anchored on the basal surface of MoS 2 .

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Destabilization of NH3BH3 by water during hydrothermolysis as a key factor in the high hydrogen evolution rates

Cited by 16 publications

References 50 publications

The Effect of Storage-Induced Changes in Ammonia Borane on Hydrogen Release during Its Low-Temperature Thermolysis

The Effect of Storage-Induced Changes in Ammonia Borane on Hydrogen Release during Its Low-Temperature Thermolysis

Formation of a Key Intermediate Complex Species in Catalytic Hydrolysis of NH3BH3 by Bimetal Clusters: Metal-Dihydride and Boron-Multihydroxy

Hydrogen Evolution Reaction Property in Alkaline Solution of Molybdenum Disulfide Modified by Surface Anchor of Nickel–Phosphorus Coating

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