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標題: | 高分散鐵中孔洞二氧化矽奈米粒子對芳香性碳氫化合物的選擇性氧化 Highly Dispersed Iron Mesoporous Silica Nanoparticle for Selective Oxidation of Aromatic Hydrocarbons |
作者: | Cheng-Feng Lee 李承峰 |
指導教授: | 牟中原(Chung-Yuan Mou) |
關鍵字: | 中孔洞二氧化矽奈米粒子,鐵,選擇性氧化,芳香烴,芳香羥基化,甲苯,苯,過氧化氫,苯酚, mesoporous silica nanoparticle,iron,selective oxidation,aromatic hydroxylation,aromatic hydrocarbons,toluene,benzene,hydrogen peroxide,phenol, |
出版年 : | 2019 |
學位: | 碩士 |
摘要: | 過度金屬高分散負載於催化劑上是一種綜合異相與勻相催化劑優點的理想策略,具有高反應性與重複使用性。在此論文中,我們藉由一鍋合成法製備一系列高比表面積與適合孔洞大小的高分散鐵中孔洞二氧化矽奈米粒子,且其大小約為100奈米,可以良好的懸浮於溶液當中,能在催化上有很好的應用。
透過電子顯微鏡、X光吸收光譜、紅外線光譜、梅斯堡光譜、X光粉末繞射的鑑定,可以推測鐵可能摻入並取代矽在矽酸鹽結構中的位置而且沒有大體積氧化鐵的聚集。另外藉由氮氣吸脫附,可以知道這些催化劑具有高比表面積與合適於催化應用的孔洞大小。 高分散地鐵可以在溫和的條件下有效地進行甲苯芳香環sp2碳氫鍵的氧化,生成主產物甲酚,與碳鏈sp3碳氫鍵的氧化,生成副產物苯甲醛以及苯甲醇,除了甲苯外,其他芳香碳氫化合物像是苯也具有很好的反應性,再者,此催化劑可輕易的從反應溶液中分離,並且能多次重複使用。在自由基捕獲劑和動力學同位素實驗的結果中,可以發現催化反應不是典型的Fenton或類Fenton的反應機構。 因為此催化劑具有高催化性和可重複性,並能進行選擇性氧化將芳香碳氫化合物轉化為酚,相信這些催化劑具有很高的潛力應用於工業催化當中。 The high dispersion of supported transition metal catalyst is an ideal strategy to combine the merits of homogeneous and heterogeneous catalysis with high catalytic activity and reusability. Herein we synthesized a series of highly dispersed iron mesoporous silica nanoparticle (Fe-MSN) by one-pot co-condensation synthesis method showing high surface area and adequate pore size for the catalytic reaction. With a particle size of ~100 nm, the catalysts could be suspended very well in the solution for catalytic application. These catalysts were characterized by TEM, SEM, X-ray absorption, FT-IR, Mössbauer spectroscopy, XRD indicating that iron incorporated into the silicate structure without aggregation of bulky iron oxide. Nitrogen adsorption-desorption isotherms demonstrate that the catalyst present a high surface area, adequate pore size for catalytic reaction. The highly dispersed Fe could efficiently carry out sp2 C-H bond of the aromatic ring of toluene to form cresols as the major product and to form benzaldehyde and benzyl alcohol in sp3 C-H bond oxidation as the minor product under a mild condition. Apart from toluene, other aromatic hydrocarbons such as benzene also show the high reactivity. Moreover, these catalysts are robust and reusable, which could be easily separated from the reaction mixture and be reused for several cycles. The results of radical trapping agent experiments and kinetic isotope experiments show the catalytic reaction is not a typical Fenton or Fenton-like mechanism. With high catalytic performance and high reusability for selective conversion of aromatic hydrocarbons into phenols, we believe these catalysts have high potential for further applied to industrial production. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/78649 |
DOI: | 10.6342/NTU201902318 |
全文授權: | 有償授權 |
顯示於系所單位: | 化學系 |
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