金屬硼氨儲氫化合物及其與硝基高能化合物相互作用機理研究
發(fā)布時間：2018-08-18 09:35
【摘要】：世界各國當前都在面臨極其嚴峻的環(huán)境問題,尤其是我國近幾年突顯的城市霧霾問題,更是需要新型的清潔能源來替換傳統(tǒng)的化石燃料以實現(xiàn)節(jié)能減排。氫能作為一種清潔能源一直引起廣泛的關(guān)注,然而其安全儲存一直是人類面臨的難題。近年來,基于金屬硼氨儲氫化合物的固態(tài)儲氫材料具有廣闊的潛在應用價值,已日益成為新能源領(lǐng)域的研究熱點之一。本論文以金屬氨硼烷為主要目標化合物,以理論計算為主要研究手段,結(jié)合已有的實驗數(shù)據(jù),系統(tǒng)研究了一元金屬氨硼烷、二元金屬氨硼烷、以及金屬氨硼烷衍生物——金屬硼氨絡(luò)合物的電子結(jié)構(gòu)、熱分解機理、熱力學和動力學性質(zhì),為尋求新型儲氫材料提供基礎(chǔ)數(shù)據(jù)和理論依據(jù)。同時,積極探索該類化合物在含能材料領(lǐng)域的應用。主要在以下方面開展了相關(guān)研究:1)金屬氨硼烷的電子結(jié)構(gòu)和釋氫機理由于單金屬氨硼烷(MNH2BH3,MAB)具有良好的儲氫性質(zhì),因此有望成為未來理想儲氫材料的重要候選物。首先,通過Monte-Carlo方法預測了未獲得單晶結(jié)構(gòu)的MAB化合物的周期性結(jié)構(gòu)。其次,通過第一性原理詳細探究了輕金屬Li、Na、K、Mg、Al和Ca為取代金屬的金屬氨硼烷固態(tài)體系的電子結(jié)構(gòu),設(shè)計并計算了其分解過程中相關(guān)釋氫和釋氨過程以及反應熱力學函數(shù)變化。最后,通過氣相分子動力學和傳統(tǒng)過渡態(tài)理論研究了其釋氫鍵的形成機理(N-Hδ+···-δH-B)、反應勢能面和釋氫速率常數(shù)。由于二元金屬氨硼烷化合物(MM'AB)中多金屬離子間的相互作用,使得其比相應的一元金屬化合物有更好的儲氫性能和釋氫表現(xiàn)。首先在試驗合成SMAB的基礎(chǔ)上,結(jié)合Monte-Carlo方法預測了SMAB的周期性結(jié)構(gòu)并對其進行了優(yōu)化。計算了4種MM'AB的相關(guān)結(jié)構(gòu)與電子能態(tài)、聲子譜及熱力學性質(zhì)。其次,詳細的討論了分子中兩種H原子的解離過程,設(shè)計并研究了分解反應中涉及的釋氫和釋氨過程及其反應焓、反應Gibbs自由能。第三,通過使用NVT系綜,結(jié)合BOMD動力學方法計算了300 K下4種化合物中兩種不同氫原子的擴散均方根速率。最后,對Na2Mg(NH2BH3)4和Na[Li(NH2BH3)2]的單分子結(jié)構(gòu),設(shè)計了不同的釋氫反應路徑,研究得到了反應最小勢能面以及溫度-速率方程。2)金屬硼氨絡(luò)合物的電子結(jié)構(gòu)和釋氫機理金屬硼氨絡(luò)合物(縮寫為AMB)相對于MAB具備更高的儲氫含量,且通過NH3上的Hδ+與[BH4]δ+中的Hδ-之間形成釋氫鍵釋氫時,反應能壘更低。通過研究Li2Al(BH4)5(NH3)6(AALB)、LiMg(BH4)3(NH3)2(AMLB)和LiCa(BH4)3(NH3)2(ACLB)共3種含LiBH4結(jié)構(gòu)的金屬硼氨絡(luò)合物的結(jié)構(gòu)、初始釋氫機理和反應熱力學性質(zhì),并與[Li(BH4)(NH3)]2(ALLB)相關(guān)性質(zhì)進行了對比。AMB由于中心金屬離子的不同,會表現(xiàn)出完全相反的分解機理和釋氫性能。通過采用Car-Parrinello分子動力學方法對兩種結(jié)構(gòu)類似、分解過程截然不同的兩種金屬硼氨絡(luò)合物Mg(BH4)2(NH3)2和Li BH4NH3的分解機理的研究,發(fā)現(xiàn)了不同類型的金屬硼氨絡(luò)合物的分解過程以及其所分解所涉及的過渡態(tài)與中間體。3)硼氨化合物對含能材料的催化性能探索研究了典型的硼氨類儲氫化合物對硝基高能化合物的熱分解過程的影響。選取了AB和LAB兩種儲氫材料分別與CL20、RDX和PETN共3種不同類型的硝基高能化合物,通過不同比例混合,得到一系列LAB/AB和CL20/RDX/PETN來探討硼氨類儲氫化合物對傳統(tǒng)硝胺或硝酸酯類猛炸藥熱分解過程中的催化性能。并通過對不同混合體系建立模型,使用傳統(tǒng)分子動力學方法計算了不同組分之間的相互作用能以及相容性,通過靜態(tài)力學方法分析其相應的力學性能,從理論上探討了復雜體系的組分、結(jié)構(gòu)和性能的關(guān)系。
[Abstract]:All countries in the world are now facing extremely serious environmental problems, especially the Urban Haze in recent years in China. It is necessary to replace traditional fossil fuels with new clean energy to achieve energy saving and emission reduction. In recent years, solid-state hydrogen storage materials based on metal boron-ammonia hydrogen storage compounds have broad potential application value and become one of the hot spots in the field of new energy. In this paper, metal ammonia-borane as the main target compound, theoretical calculation as the main research means, combined with existing experimental data, a systematic study of gold monomer was carried out. The electronic structure, thermal decomposition mechanism, thermodynamic and kinetic properties of metal boron ammonia complexes, which belong to ammonia borane, binary metal ammonia borane and derivatives of metal ammonia borane, provide basic data and theoretical basis for seeking new hydrogen storage materials. At the same time, actively explore the application of these compounds in energetic materials. Relevant studies have been carried out: 1) The electronic structure and hydrogen release mechanism of metal aminoborane (MNH2BH3, MAB) are expected to be an important candidate for future ideal hydrogen storage materials because of its good hydrogen storage properties. First, the periodic structure of MAB compounds without single crystal structure is predicted by Monte-Carlo method. The electronic structure of light metals Li, Na, K, Mg, Al and Ca as substituted metals in solid-state ammonia-borane system was investigated in detail by first-principles. The processes of hydrogen release and ammonia release and the changes of thermodynamic functions during the decomposition were designed and calculated. Finally, the hydrogen release bonds were studied by gas-phase molecular dynamics and traditional transition state theory. The formation mechanism (N-Hdelta+... - Delta H-B), the reaction potential energy surface and the rate constant of hydrogen release are discussed. Due to the interaction between the polymetallic ions in the binary metal ammonia borane compound (MM'AB), it has better hydrogen storage and hydrogen release performance than the corresponding monometallic compound. The periodic structure of SMAB was measured and optimized. The electronic energy states, phonon spectra and thermodynamic properties of four MM'AB were calculated. Secondly, the dissociation process of two H atoms in the molecule was discussed in detail. The hydrogen and ammonia release processes involved in the decomposition reaction and their reaction enthalpies, Gibbs free energy were designed and studied. By using NVT ensemble and BOMD kinetic method, the diffusion RMS rates of two different hydrogen atoms in four compounds at 300 K were calculated. Finally, different hydrogen release pathways were designed for the single molecular structures of Na2Mg (NH2BH3) 4 and Na [Li (NH2BH3) 2). The minimum potential energy surface and the TEMPERATURE-RATE equation were obtained. The electronic structure and hydrogen release mechanism of ammonia complex metal boron ammonia complex (abbreviated as AMB) has higher hydrogen storage content than MAB, and the reaction barrier is lower when the hydrogen release bond is formed between Hdelta + on NH3 and Hdelta - in [BH4] delta + to release hydrogen. Through the study of Li2Al (BH4) 5 (NH3) 6 (AALB), LiMg (BH4) 3 (NH3) 2 (AMLB) and LiCa (BH4) 3 (NH3) 2 (ACLB) 3 co-3. The structure, initial hydrogen release mechanism and reaction thermodynamic properties of a metal boron-ammonia complex containing LiBH4 structure were compared with those of [Li(BH4)(NH3)]2(ALLB). AMB exhibited completely opposite decomposition mechanism and hydrogen release performance due to the difference of central metal ions. Car-Parrinello molecular dynamics method was used to study the two kinds of metal boron-ammonia complexes. The decomposition mechanism of two metal boron-ammonia complexes Mg(BH4)2(NH3)2 and Li BH4 NH3 with similar structure and different decomposition process was studied. The decomposition process of different metal boron-ammonia complexes and the transition state and intermediate involved in their decomposition were found. 3) The catalytic performance of boron-ammonia compounds on energetic materials was studied. The effects of boron-ammonia hydrogen storage compounds on the thermal decomposition process of nitro-high-energy compounds were studied. Three different types of nitro-high-energy compounds, namely, AB and LAB hydrogen storage materials and CL20, RDX and PETN, were selected and mixed in different proportions. A series of LAB/AB and CL20/RDX/PETN were obtained to investigate the effects of boron-ammonia hydrogen storage compounds on traditional nitramine or nitrate. Catalytic performance of ester explosives during thermal decomposition was studied. The interaction energy and compatibility of different components were calculated by traditional molecular dynamics method. The corresponding mechanical properties were analyzed by static mechanics method. Components, structures and properties of complex systems were discussed theoretically. Energy relations.
【學位授予單位】：北京理工大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：O641.3
本文編號：2189071
[Abstract]:All countries in the world are now facing extremely serious environmental problems, especially the Urban Haze in recent years in China. It is necessary to replace traditional fossil fuels with new clean energy to achieve energy saving and emission reduction. In recent years, solid-state hydrogen storage materials based on metal boron-ammonia hydrogen storage compounds have broad potential application value and become one of the hot spots in the field of new energy. In this paper, metal ammonia-borane as the main target compound, theoretical calculation as the main research means, combined with existing experimental data, a systematic study of gold monomer was carried out. The electronic structure, thermal decomposition mechanism, thermodynamic and kinetic properties of metal boron ammonia complexes, which belong to ammonia borane, binary metal ammonia borane and derivatives of metal ammonia borane, provide basic data and theoretical basis for seeking new hydrogen storage materials. At the same time, actively explore the application of these compounds in energetic materials. Relevant studies have been carried out: 1) The electronic structure and hydrogen release mechanism of metal aminoborane (MNH2BH3, MAB) are expected to be an important candidate for future ideal hydrogen storage materials because of its good hydrogen storage properties. First, the periodic structure of MAB compounds without single crystal structure is predicted by Monte-Carlo method. The electronic structure of light metals Li, Na, K, Mg, Al and Ca as substituted metals in solid-state ammonia-borane system was investigated in detail by first-principles. The processes of hydrogen release and ammonia release and the changes of thermodynamic functions during the decomposition were designed and calculated. Finally, the hydrogen release bonds were studied by gas-phase molecular dynamics and traditional transition state theory. The formation mechanism (N-Hdelta+... - Delta H-B), the reaction potential energy surface and the rate constant of hydrogen release are discussed. Due to the interaction between the polymetallic ions in the binary metal ammonia borane compound (MM'AB), it has better hydrogen storage and hydrogen release performance than the corresponding monometallic compound. The periodic structure of SMAB was measured and optimized. The electronic energy states, phonon spectra and thermodynamic properties of four MM'AB were calculated. Secondly, the dissociation process of two H atoms in the molecule was discussed in detail. The hydrogen and ammonia release processes involved in the decomposition reaction and their reaction enthalpies, Gibbs free energy were designed and studied. By using NVT ensemble and BOMD kinetic method, the diffusion RMS rates of two different hydrogen atoms in four compounds at 300 K were calculated. Finally, different hydrogen release pathways were designed for the single molecular structures of Na2Mg (NH2BH3) 4 and Na [Li (NH2BH3) 2). The minimum potential energy surface and the TEMPERATURE-RATE equation were obtained. The electronic structure and hydrogen release mechanism of ammonia complex metal boron ammonia complex (abbreviated as AMB) has higher hydrogen storage content than MAB, and the reaction barrier is lower when the hydrogen release bond is formed between Hdelta + on NH3 and Hdelta - in [BH4] delta + to release hydrogen. Through the study of Li2Al (BH4) 5 (NH3) 6 (AALB), LiMg (BH4) 3 (NH3) 2 (AMLB) and LiCa (BH4) 3 (NH3) 2 (ACLB) 3 co-3. The structure, initial hydrogen release mechanism and reaction thermodynamic properties of a metal boron-ammonia complex containing LiBH4 structure were compared with those of [Li(BH4)(NH3)]2(ALLB). AMB exhibited completely opposite decomposition mechanism and hydrogen release performance due to the difference of central metal ions. Car-Parrinello molecular dynamics method was used to study the two kinds of metal boron-ammonia complexes. The decomposition mechanism of two metal boron-ammonia complexes Mg(BH4)2(NH3)2 and Li BH4 NH3 with similar structure and different decomposition process was studied. The decomposition process of different metal boron-ammonia complexes and the transition state and intermediate involved in their decomposition were found. 3) The catalytic performance of boron-ammonia compounds on energetic materials was studied. The effects of boron-ammonia hydrogen storage compounds on the thermal decomposition process of nitro-high-energy compounds were studied. Three different types of nitro-high-energy compounds, namely, AB and LAB hydrogen storage materials and CL20, RDX and PETN, were selected and mixed in different proportions. A series of LAB/AB and CL20/RDX/PETN were obtained to investigate the effects of boron-ammonia hydrogen storage compounds on traditional nitramine or nitrate. Catalytic performance of ester explosives during thermal decomposition was studied. The interaction energy and compatibility of different components were calculated by traditional molecular dynamics method. The corresponding mechanical properties were analyzed by static mechanics method. Components, structures and properties of complex systems were discussed theoretically. Energy relations.
【學位授予單位】：北京理工大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：O641.3
【參考文獻】
相關(guān)期刊論文 前1條
1 貢雪東,肖鶴鳴,高貧;季戊四醇四硝酸酯的分子結(jié)構(gòu)和熱解機理[J];有機化學;1997年06期
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