利用 DFT+U 理論探討乙烷氧化脫氫反應在 MoO3, Mo-V, Mo-V-W 催化劑上的反應機構

Abstract

相比於傳統方法,乙烷轉化乙烯技術具有高產率低耗能的優點。

原料乙烷可由富含乙烷的天然氣油田,或石化工業的副產物中中提出。

半導體表面對於烴類的催化反應已被廣泛研究,如三氧化鉬和五氧化

二釩的半導體表面。Mo-V-O 基底催化劑已被開發成 ODH(氧化脫氫)

反應的催化劑。在一般化學生產工業中,乙烯主要由長碳鍊原料蒸汽

裂解製成。而由乙烷的天然氣脫氫可以更簡單的得到乙烯的直接產

Mohammed Al-Hazmi& YongMan Choi 等人製造出 Mo-V-Mn-W

催化劑,以進行短接觸時間的乙烷氧化脫氫反應。隨著不同的鎢荷載

量,發現對於乙烯有不同的選擇性。

本研究利用第一性原理計算,探討乙烷在純三氧化鉬表面的脫氫

反應機制,並透過表面無共吸附氫模型,比較三氧化鉬摻雜不同比例

的V&W,催化乙烷的脫氫反應機構。並藉由尋找可能的反應的機構,

預測乙烷轉化過程中可能的產物,以及找出最適合進行乙烷催化乙烯

的催化劑表面。

Process of ethane conversion ethylene compared to traditional methods have advantage of having a high yield and low energy cost. Ethane can be isolated from natural gas, and as a byproduct of petroleum refining. The semiconductor surface of the hydrocarbon reaction catalysts have been widely studied, such as MoO3& V2O5 semiconductor surfaces. The Mo–V–O-based catalysts had be developed into catalyst of ODH(oxidative dehydrogenation) reaction. As the product generally & wide variety of the chemical industry, ethylene mostly made of steam-cracking. By ethane in the natural gas, it dehydrogenation can get direct product of ethylene. Mohammed Al-Hazmi & YongMan Choi et al. create Mo-V-Mn-W catalysts for ethane oxidative dehydrogenation in short contact time reaction. With varying tungsten loadings, found in different selectivity to ethylene. This study uses the first-principles calculations to explore ethane dehydrogenation reaction mechanism in a pure MoO3 surface, and compare the ethane dehydrogenation reaction mechanisms on different transition metal catalysts doping with V& W. By looking for possible reaction mechanism. We prediction probable product of ethane conversion process, and identify the most suitable catalyst surface for ethane transform ethylene.