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標題: | SBA-15負載釩鉬鎢混合金屬氧化物對氣相甘油脫水氧化反應研究 Gas-phase Oxidehydration of Glycerol over V/Mo/W Mixed Oxides Supported on SBA-15 |
作者: | Li-Min Tsao 曹立敏 |
指導教授: | 鄭淑芬(Soofin Cheng) |
關鍵字: | 甘油,丙烯酸,脫水氧化反應,SBA-15, Glycerol,Acrylic acid,Oxidehydration,SBA-15, |
出版年 : | 2017 |
學位: | 碩士 |
摘要: | 甘油脫水氧化形成丙烯酸的反應在工業上具有高度經濟價值,本研究欲探討同時具有酸性及氧化力的觸媒,以一步反應將甘油脫水氧化形成丙烯酸。此催化過程包含兩個連續的反應,先利用觸媒的酸性將甘油脫水形成丙烯醛,丙烯醛緊接著氧化形成丙烯酸。本研究利用不同比例之V/Mo/W金屬氧化物及將其負載於SBA-15上,觀察對催化所造成的影響,同時利用XRD、NH3-TPD、SEM 和 N2 吸脫附技術來探討不同因素所造成的影響。
催化條件測試中發現,當溫度為300oC、N2/O2/glycerol = 71/4.5/1、總體流速為50 mL/min及甘油進樣速率為3 mL/h時,擁有最佳的催化條件,將V/Mo/W金屬氧化物負載於SBA-15上會增加丙烯醛及丙烯酸的選擇率,同時降低氣體CO及CO2的選擇率。已知V對於丙烯醛氧化反應是有幫助的,然而,當V/W比例增加時,會使過度氧化的產物COx增加,而當V/Mo比例增加時,COx選擇率反而下降。在調整金屬比例V/Mo/W = 1/0/4後負載於SBA-15上,觸媒30%W4V1-SBA-15可得到最高的丙烯酸選擇率15%。 The catalytic behaviors of bifunctional catalysts with acidic and oxidizing properties were investigated in the one-step oxidehydration of glycerol to acrylic acid. The demonstrated reaction involves two consecutive steps of acid-catalysed glycerol dehydration into acrolein and aldehyde oxidation into acrylic acid. The aim of this study is to optimize the components of V/Mo/W mixed oxides and to examine the effect of supporting V/Mo/W over platelet SBA-15. The catalysts were characterized by XRD, NH3-TPD, SEM and N2 sorption techniques. The optimal reaction condition was 300oC, N2/O2/glycerol = 71/4.5/1, N2 flow rate of 50 mL/min, glycerol flow rate 3 mL/h. Supporting V/Mo/W mixed oxides on SBA-15 would enhance the yields of acrolein and acrylic acid and decrease the COx yields at the same time. On the other hand, V are active in oxidation reaction. However, the yields of over-oxidized COx products increased when the V/W ratio increased. On the contrary, the COx yield decreased when the V/Mo ratio increased. As a result, the highest yield of acrylic acid was obtained over the SBA-15 supported catalyst with V/Mo/W atomic ratio of 1/0/4. The highest acrylic acid selectivity of 15% was obtained over 30%W4V1-SBA-15 catalyst. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/68636 |
DOI: | 10.6342/NTU201703844 |
全文授權: | 有償授權 |
顯示於系所單位: | 化學系 |
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