以第一原理的計算方法分別探討氫化氰的氫化反應以及頁岩層中油母質的裂解現象，作為開發替代能源之相關應用

CCUR > College of Natural Science and Engineering > College of Science > Department of Chemistry & Graduate Institute of Applied Chemistry > project > Item 987654321/30458

Please use this identifier to cite or link to this item: https://irlib.pccu.edu.tw/handle/987654321/30458

Title:	以第一原理的計算方法分別探討氫化氰的氫化反應以及頁岩層中油母質的裂解現象，作為開發替代能源之相關應用 First-Principles Calculations to Explore the (1) Hcn Hydrogenation on Metallic/Bimetallic Surfaces and Nanoparticle Substrates, (2) Detailed Studies of Pyrolysis Behaviors of Kerogen in the Shale
Authors:	陳輝龍
Contributors:	化學系
Date:	2015-08
Issue Date:	2015-09-04 11:28:19 (UTC+8)
Abstract:	空氣中氰化氫(HCN)的濃度含量約為300mg/m3 時，在毒殺一個人所需的時間大約只要10-60 分鐘，若在3500PPM(約3200mg/m3)則只需要一分鐘。所以HCN 分子對人體具有強烈的毒性，原因是HCN 中的氰離子會進入粒線體中的細胞色素C 氧化酶，並與細胞色素C 中的亞鐵離子結合，造成電子傳遞中斷，最後導致細胞呼吸中斷並死亡。因此HCN 被認為是環境毒害物質，所以實驗學家跟理論學家針對這相關的議題已經討論了很久。自化學工業開始廣泛使用甲胺以來，針對於HCN 分子氫化合成甲胺(HCN + 2H2 H3CNH2)的研究也越來越多。在本計畫的第一個1.5 年中探討將HCN 分子於不同金屬表面上的氫化反應過程並作完整的路徑分析，其中包括(1)具有體心立方晶系的金屬及雙金屬表面，如Cr(111)，Fe(111)，Mo(111)，W(111)，Cr@ Fe(111)，Cr@Mo(111)， Cr@W(111)，Fe@Cr(111)，Fe@Mo(111)，Fe@W(111)，Mo@Cr(111)，Mo@Fe(111)， Mo@W(111)，W@Cr(111)，W@Fe(111)和W@Mo(111)…等，(2)設計更有效率的奈米催化模型，如Cr，Fe，Mo，W 等bcc 金屬，或Cu，Ag，Au，Ni，Pd，Pt，Rh，Al，及 Pb 等fcc 金屬。我們希望經由這些相關的研究中可以提供產業界一個最低能障的催化反應方式，如金屬表面或是奈米金屬下進行HCN 的氫化反應，得到對環境沒有毒害的物質或產業上原料等，H3CNH2、CH4,及NH3。此外，因為現今石油的存量逐漸減少而不足，尋找替代能源變得非常重要。從先前一些相關的研究報導中，發現頁岩層中的油母質結構包含有一些碳氫類的芳香烴以及含有氮、氧和硫等的芳香族雜環化合物。然而，氮在油母質是以雜環的形式存在，例如：吡啶(pyridine)、吡咯(pyrrole)、喹啉(quinoline)和吲哚(indole)等。在這第二個1.5 年提案計畫書中，我們將利用泛函理論原理(density functional theory, DFT)來探討吡啶的熱分解( pyrolysis)反應機制，希望藉由研究結果中，可以獲得下面三個重要的資訊(1) 清楚的了解吡啶的熱分解反應機制及所有可能的反應路徑和產物，(2)提供實驗學家或產業界對於吡啶的熱分解過程中究竟所需的溫度和壓力條件為何， (3)其他油母質所含的分子結構的進行相關的熱解反應比較和探討(如: 吡咯、喹啉和吲哚等)，和(4)應用在表面金屬催化來進行分解反應。因此，我們使用較高層級的全初始量子化學方法( ab initio quantum chemistry methods)來探討吡啶的熱分解反應路徑。至於熱分解的過程，我們考慮的三種可能的方向，如C-H 斷鍵，C-N 斷鍵，C-C 斷鍵，以及H 轉移等，藉由計算結果可以獲得最佳的反應路徑，以及了解複雜的反應機制將是本計畫最主要的任務，我們將全力完成這個多年期計畫。 A hydrogen cyanide (HCN) concentration of 300 mg/m3 in air will kill a human within 10–60 minutes. A hydrogen cyanide concentration of 3500 ppm (about 3200 mg/m3) will kill a human in about 1 minute. The toxicity is caused by the cyanide ion, which halts cellular respiration by acting as a non-competitive inhibitor for an enzyme in mitochondria called cytochrome c oxidase. Specifically CN- binds to Fe in the heme subunit in cytochromes, interrupting electron transfer. Therefore, the HCN was believed to contribute the severe damage to our environment, has been of interest to experimentalists and theoreticians for a long time. Methylamine (H3CNH2) synthesis from HCN hydrogenation (HCN + 2H2 H3CNH2) has been studied recently since the H3CNH2 could provide a lot of applications in the chemicals industry. The purposes of this first 1.5 year project is to address the fully picture for the hydrogenation of HCN on a series of varied substrates, including: (1) metallic and bimetallic surfaces with body-centered-cubic lattice, such as Cr(111), Fe(111), Mo(111), W(111), Cr@ Fe(111), Cr@Mo(111), Cr@W(111), Fe@Cr(111), Fe@Mo(111), Fe@W(111), Mo@Cr(111), Mo@Fe(111), Mo@W(111), W@Cr(111), W@Fe(111) and W@Mo(111)…etc., (2) rational design of better nanoparticle catalytic models, such as Cr, Fe, Mo and W nanoparticles (bcc packing of metals), as well as Cu, Ag, Au, Ni, Pd, Pt, Rh, Al, and Pb nanoparticles (fcc packing of metals). We believe that this understanding is vital in our future study for rational design of better surface substrates and/or nano-scaled particles, in which they are not harmful to our environment and possibly with lower activation barriers for the synthesis of H3CNH2 or CH4, and NH3 from HCN hydrogenation reactions. Furthermore, alternative energy resource become very important because the fuel oil produce decreased recently. Hence, the research and exploitation of oil shale still have attracted more and more attention in the world. In the previously reports, the structure of oil shale involves a complex mixture of aromatic hydrocarbons and heterocyclic aromatic compounds containing nitrogen, oxygen, and sulfur. However, it is well-known that chemically bound nitrogen in oil shale is predominantly in the form of heterocycles such as pyridine and pyrrole ring systems. In this second 1.5 year project proposal, the pyrolysis mechanisms of pyridine were calculated by density functional theory (DFT). The purpose of this work is as follows: (1) to clarify the pyrolysis mechanisms of pyridine in all of the possible reaction pathways and products, (2) to provide the decomposition behaviors of pyridine in different conditions of temperature and pressure, (3) to compare with the analogous pyrolysis reactions of pyrrole, quinoline and indole, and (4) by using the different catalytic metal surfaces or nanoparticles to make these pyrolysis reaction much more facile. Therefore, we set out to characterize the energetic reaction pathways for the pyrolysis of pyridine using various high level ab initio quantum chemistry methods. As to which pyrolysis processes, such as C-H bond rupture, C-N bond cleavage, C-C bond cleavage, and H migration, could do the best favorable pathway, as well as the understanding of the complicated reaction mechanisms will be the main task that we have to overcome completely in this 1.5 year project.
Appears in Collections:	[Department of Chemistry & Graduate Institute of Applied Chemistry ] project

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	441	View/Open

View Licence

Loading...