Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface

碩士 === 國立臺灣科技大學 === 化學工程系 === 96 === Ethanol decomposition on clean α-Al2O3 (0001) and Ni/α-Al2O3 (0001) surface was studied using periodic DFT calculations. Our results are compared with the available experimental findings of ethanol steam reforming reaction. For n Ni atoms (n=3–4) deposition on α-...

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Main Authors: Ya-chin Cheng, 程雅琴
Other Authors: Jyh-Chiang Jiang
Format: Others
Language:en_US
Published: 2008
Online Access:http://ndltd.ncl.edu.tw/handle/17855359730641666318
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spelling ndltd-TW-096NTUS50630332016-05-13T04:15:16Z http://ndltd.ncl.edu.tw/handle/17855359730641666318 Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface 以密度泛函理論研究乙醇在Ni/α-Al2O3(0001)觸媒表面上之裂解反應 Ya-chin Cheng 程雅琴 碩士 國立臺灣科技大學 化學工程系 96 Ethanol decomposition on clean α-Al2O3 (0001) and Ni/α-Al2O3 (0001) surface was studied using periodic DFT calculations. Our results are compared with the available experimental findings of ethanol steam reforming reaction. For n Ni atoms (n=3–4) deposition on α-Al2O3(0001) surface, the preferential structure is forming cluster rather than dispersion on surface. Triangle Ni3 cluster adsorption on 2 × 2 α-Al2O3(0001) surface is used to represent Ni/α-Al2O3(0001) surface. The considered possible pathways for ethanol decomposition on clean α-Al2O3 (0001) and Ni/α-Al2O3 (0001) surface include dehydrogenation and C-C bond cleavage. Clean α-Al2O3 (0001) surface favors the reaction of ethanol dehydration to ethylene or leading to stable intermediate (CH2CHO) which finally occupies the active site of surface. Ni/α-Al2O3 (0001) surface shows high activity to inhibit coke formation, one feasible channel leading to C-C bond breaking was proposed. The C-C bond in CH2CO intermediate can be weaken via transforming the adsorption structure to increase the coordination number of the two carbon atoms with the surface of Ni cluster. The CH2CH2O(a) → CH2CHO (a) + H(a) reaction is the rate-determining step for the overall reaction (‡E = 1.20 eV). CO oxidation on Ni/α-Al2O3 (0001) surface is also investigated and the DOS analysis for CO adsorption on Ni bridge site shows that the interaction is mainly contributed from CO(5σ)-Ni charge donation and Ni(d)-2π* backdonation. Jyh-Chiang Jiang 江志強 2008 學位論文 ; thesis 107 en_US
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language en_US
format Others
sources NDLTD
description 碩士 === 國立臺灣科技大學 === 化學工程系 === 96 === Ethanol decomposition on clean α-Al2O3 (0001) and Ni/α-Al2O3 (0001) surface was studied using periodic DFT calculations. Our results are compared with the available experimental findings of ethanol steam reforming reaction. For n Ni atoms (n=3–4) deposition on α-Al2O3(0001) surface, the preferential structure is forming cluster rather than dispersion on surface. Triangle Ni3 cluster adsorption on 2 × 2 α-Al2O3(0001) surface is used to represent Ni/α-Al2O3(0001) surface. The considered possible pathways for ethanol decomposition on clean α-Al2O3 (0001) and Ni/α-Al2O3 (0001) surface include dehydrogenation and C-C bond cleavage. Clean α-Al2O3 (0001) surface favors the reaction of ethanol dehydration to ethylene or leading to stable intermediate (CH2CHO) which finally occupies the active site of surface. Ni/α-Al2O3 (0001) surface shows high activity to inhibit coke formation, one feasible channel leading to C-C bond breaking was proposed. The C-C bond in CH2CO intermediate can be weaken via transforming the adsorption structure to increase the coordination number of the two carbon atoms with the surface of Ni cluster. The CH2CH2O(a) → CH2CHO (a) + H(a) reaction is the rate-determining step for the overall reaction (‡E = 1.20 eV). CO oxidation on Ni/α-Al2O3 (0001) surface is also investigated and the DOS analysis for CO adsorption on Ni bridge site shows that the interaction is mainly contributed from CO(5σ)-Ni charge donation and Ni(d)-2π* backdonation.
author2 Jyh-Chiang Jiang
author_facet Jyh-Chiang Jiang
Ya-chin Cheng
程雅琴
author Ya-chin Cheng
程雅琴
spellingShingle Ya-chin Cheng
程雅琴
Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface
author_sort Ya-chin Cheng
title Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface
title_short Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface
title_full Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface
title_fullStr Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface
title_full_unstemmed Density functional theory study of ethanol decomposition reaction over Ni/α-Al2O3(0001) surface
title_sort density functional theory study of ethanol decomposition reaction over ni/α-al2o3(0001) surface
publishDate 2008
url http://ndltd.ncl.edu.tw/handle/17855359730641666318
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