本文選題：沸石分子篩 + 晶體結構��； 參考：《吉林大學》2017年博士論文

【摘要】：沸石分子篩是一類具有規(guī)則分布微孔結構的無機晶體材料,目前被廣泛應用于催化、吸附分離、離子交換等工業(yè)領域。所有的分子篩骨架結構均由TO4四面體(T原子指四配位的硅、鋁、磷等原子)通過共享橋氧原子相互連接而成。由于其在工業(yè)領域的廣泛應用和巨大的商業(yè)價值,開發(fā)具有優(yōu)異性能的新穎分子篩拓撲結構一直是人們追求的目標。截至目前,人們已發(fā)現(xiàn)232種分子篩骨架拓撲類型。由于人們對分子篩晶體的形成機制尚未明確,現(xiàn)階段分子篩材料的研發(fā)仍以傳統(tǒng)的經(jīng)驗試錯法為主,充滿盲目性與偶然性,導致新穎分子篩材料的研發(fā)一直充滿挑戰(zhàn)。以功能需求為導向、利用計算機手段預測尚未被發(fā)現(xiàn)的理論結構,為人們提供了豐富的靶向合成目標,是分子篩材料研發(fā)的一條新的途徑。在人們已發(fā)現(xiàn)的232種分子篩拓撲類型中,有10余種結構是先經(jīng)過理論預測、而后在實驗中被合成出來的。假想分子篩結構的計算機預測包含兩方面內(nèi)容:(1)尋找假想結構合理性的評價依據(jù);(2)利用計算機搭建假想分子篩的結構模型。針對目前這兩個領域所面臨的主要問題,結合分子篩材料的結構特點,通過計算機理論計算,我們發(fā)現(xiàn)了兩種分子篩結構合理性評價的新規(guī)則,并提出了以枚舉對稱位置組合方式高效搭建假想分子篩結構模型的新方法。本論文取得的研究成果包括:1、提出衡量環(huán)扭曲的非近鄰氧原子最短間距規(guī)則,檢測出大量用傳統(tǒng)手段無法檢出的不合理假想結構。以往的結構合理性評價方法無法檢出因環(huán)扭曲而形成的不合理結構。針對這一問題,我們提出了非近鄰氧原子最短間距規(guī)則(簡稱DO…O規(guī)則)。與以往結構評價規(guī)則不同的是,DO…O規(guī)則更側重于考察環(huán)中氧原子對環(huán)扭曲的貢獻,因此能夠檢出大量傳統(tǒng)方法無法檢出的含有扭曲環(huán)的不合理假想結構。2、改進了局域原子間距規(guī)則,使其能夠直接用于具有對稱性的假想結構,將結構檢測的效率提升至少一個數(shù)量級。我們在前期工作中所提出的局域原子間距規(guī)則(簡稱LID規(guī)則)是目前分子篩領域最重要的結構規(guī)則,對不合理結構具有較高的識別效率。但局域原子間距的計算需要在無對稱約束條件下進行,計算量非常大,不適用于對海量假想結構的高通量評價與篩選。針對這一問題,我們提出了對稱約束條件下的局域原子間距規(guī)則,在保證其準確率不變的前提下,使整體計算量降低至少一個數(shù)量級,從而提高了假想分子篩結構的評價效率。3、提出了枚舉對稱位置組合的結構模型搭建方法,大幅提升假想分子篩結構模型的搭建效率。國際主流的結構模型搭建方法往往不能均衡的搜索構象空間,因此忽略了很多合理的假想結構模型。為此,我們提出了枚舉對稱位置組合搭建分子篩結構模型的方法,通過限制每個原子的對稱位置,實現(xiàn)對整個構象空間的均衡搜索。與國際主流方法對比,我們提出的方法具有更高的運算效率,在同等條件下能夠搭建出更多合理的假想分子篩結構模型。在此基礎上,我們在Ibca空間群開展了假想分子篩的結構預測,最終得到235種全新的分子篩拓撲類型。本論文的研究為分子篩結構預測提供了新的方法,加深了人們對分子篩結構化學的認識,進一步豐富了假想分子篩的結構數(shù)據(jù)庫,為功能導向的分子篩研發(fā)提供了靶向結構,也為后續(xù)將要開展的性能篩選、定向合成等工作提供了依據(jù)。
[Abstract]:Zeolite molecular sieve is a kind of inorganic crystal material with regular distribution of microporous structure. It is now widely used in the field of catalysis, adsorption separation, ion exchange and other industrial fields. All the molecular sieve framework structure is made up of TO4 tetrahedron (T atom refers to four coordination silicon, aluminum, phosphorus and other atoms) through shared bridge oxygen atoms. The wide application and great commercial value of the industry and the development of novel molecular sieve topology with excellent performance have always been the goal. Up to now, 232 kinds of molecular sieve framework topology types have been found. Because of the fact that the formation mechanism of molecular sieve crystal is not yet clear, the research and development of molecular sieve materials at present is still traditional The experience and error method, which is full of blindness and contingency, leads to the development of new molecular sieve materials, which is full of challenges. Based on functional requirements, the theoretical structure has been predicted by computer, and it provides a rich target of target synthesis for people. It is a new way for the research and development of sub sieve materials. In the present 232 types of molecular sieve topology types, more than 10 kinds of structures are predicted first and then synthesized in the experiment. The computer prediction of the imaginary molecular sieve structure contains two aspects: (1) finding the evaluation basis for the reasonableness of the imaginary structure; (2) constructing the structural model of the hypothetical molecular sieve using the computer. For the present two The main problems faced by the field, combined with the structural characteristics of molecular sieve materials, through computer theory calculation, we found the new rules of the two kinds of molecular sieve structure rationality evaluation, and put forward a new method to construct the model of the hypothetical molecular sieve structure by enumerating symmetrical position combination method. The research achievements of this paper include: 1 According to the rule of the shortest distance between the non nearest neighbor oxygen atom of the ring, a large number of irrational hypothetical structures can not be detected by the traditional methods. The previous structural rationality evaluation method can not detect the unreasonable structure caused by the ring distortion. In this case, we have proposed the shortest distance rule of the non nearest neighbor oxygen atom (DO... O rule). Unlike previous structural evaluation rules, DO... The O rule is more focused on investigating the contribution of oxygen atom to ring distortion in the ring, so we can detect a large number of undetected false imaginary structures,.2, which can not be detected by traditional methods, and improve the local atomic spacing rules, so that they can be used directly for the hypothetical structure with symmetry, and the efficiency of structure detection is raised at least one order of magnitude. The local interatomic spacing rules (LID rules) proposed in the previous work are the most important structural rules in the field of molecular sieves, and have high recognition efficiency for irrational structures. However, the calculation of local interatomic spacing needs to be carried out under the condition of asymmetric constraints, and the computation is very large and is not suitable for the high level of imaginary structures. In order to solve this problem, we put forward the rule of the local atomic spacing under the condition of symmetry constraints. On the premise of ensuring its accuracy, the overall calculation is reduced at least one order of magnitude, thus the evaluation efficiency of the structure of the hypothetical molecular sieve is improved.3, and the structure model of the enumerated symmetric position combination is put forward. Methods, the construction efficiency of the imaginary molecular sieve structure model is greatly improved. The international mainstream structure model building method is often unable to balance the conformation space. Therefore, many reasonable hypothetical structural models are ignored. Therefore, we put forward a method to enumerate the structure model of the molecular sieve by enumerating the symmetrical position combination, by limiting each atom. On the basis of the Ibca space group, we carry out the prediction of the structure of the hypothetical molecular sieves. To 235 new types of molecular sieve topology types, this paper provides a new method for molecular sieve structure prediction, deepens people's understanding of molecular sieve structure chemistry, enriches the structure database of hypothetical molecular sieves, provides target structure for functional molecular sieve research and development, and also provides performance screening for follow-up. It provides a basis for the work of directional synthesis.
【學位授予單位】：吉林大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：TQ424.25

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