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標題: | 疏水性材料六方氮化硼擔載Cu/ZnO應用於二氧化碳氫化產甲醇 Hydrophobic h-BN Supported Cu/ZnO for CO2 Hydrogenation to Methanol |
作者: | 胡芮齊 Jui-Chi Hu |
指導教授: | 吳紀聖 Chi-Sheng Wu |
關鍵字: | 二氧化碳氫化,甲醇,氮化硼,疏水性,銅鋅觸媒, CO2 hydrogenation,Methanol,Boron Nitride,Hydrophobic,Cu/ZnO catalyst, |
出版年 : | 2023 |
學位: | 碩士 |
摘要: | 甲醇(CH3OH)是工業上廣泛使用的化學原料之一。由於它擁有高的氫碳比,並且在常溫下是以液態存在,因此在文獻中常被討論作為氫能載體。二氧化碳氫化產甲醇不僅可以將氫氣儲存為甲醇,又可以達到二氧化碳再利用的目的,是近年來備受矚目的研究之一。工業上生產甲醇是以合成氣作為原料,並使用Cu/ZnO/Al2O3觸媒,但是由於熱力學限制,此反應傾向在高壓(5-10 MPa)的環境下操作。再者,反應過程中水是不可避免的副產物,然而水的產生不僅會抑制甲醇的選擇率,還會加速Cu的氧化和ZnO的聚集而使觸媒失活。
本研究旨在探討以疏水性材料六方氮化硼(h-BN)作為銅鋅觸媒的載體,進行二氧化碳氫化反應產甲醇。h-BN會先利用超音波處理或modified Hummers’ method進行前處理以增加金屬的附著度,再將銅、鋅等金屬以沉積-沉澱法擔載於h-BN上。我們設計了不同的方法和合成參數,討論不同的 h-BN 前處理方法、觸媒合成方法、金屬擔載量和促進劑種類對觸媒活性的影響。催化反應在 230 oC 和 1.0 MPa下進行。結果顯示,相較於商用觸媒,所有以h-BN為載體的觸媒均表現出較高的甲醇選擇性,並且在本研究中40 wt% Cu/ZnO/La2O3加上 0.3 mol% Mg 擔載在經modified Hummers’ method修飾的 h-BN 上表現出最高的觸媒活性。在200 oC、1.0 MPa下,甲醇時空產率達到105 mgMeOH/gcat/hr。本研究應用XRD、SEM、EDS、H2-TPR、CO2-TPD、XPS和接觸角等儀器對觸媒物性進行量測,討論對活性測試結果的影響。並根據不同反應條件下的結果進行了反應動力學擬合分析。此外,我們還在工研院進行高壓反應測試,已確認了觸媒在高壓環境下有更佳的表現,以利於後續對於h-BN觸媒的開發。 Methanol (CH3OH) is widely used for industrial purposes as a common chemical feedstock. Because of its high hydrogen-to-carbon ratio and being liquid under ambient conditions, methanol is widely recommended as hydrogen energy carrier in literature. CO2 hydrogenation to methanol not only stores hydrogen as methanol but also achieves the purpose of CO2 recycling. Industrially, Cu/ZnO/Al2O3 catalyst is used in CO2 hydrogenation to methanol, which needs to be operated under very high pressure (5-10 MPa) from the thermodynamic point of view. In addition, water, an inevitable by-product during the reaction, not only decreases the methanol selectivity but also promotes the oxidation of Cu and the aggregation of ZnO, resulting in the deactivation of the catalyst. In this study, we used hydrophobic material, hexagonal boron nitride (h-BN), as the support of Cu/ZnO catalyst for CO2 hydrogenation to methanol. h-BN was pretreated by sonication or modified Hummers method to increase the adhesion of metal oxide. Cu/Zn metals were loaded on h-BN by the deposition-precipitation method. We designed different procedures and loading parameters to synthesize catalysts, including h-BN pretreatment method, catalyst synthesis method, metal loading, and promoter. The reaction was carried out at 230 oC and 1 MPa. The result indicated that all catalysts using h-BN as support showed higher methanol selectivity compared with those by Al2O3 support. We found that the catalyst using 40 wt% Cu/ZnO/La2O3 with 0.3 mol% Mg loaded on h-BN pretreated with modified Hummers’ method showed the highest activity in this study. The space-time yield of methanol reached 105 mgMeOH/gcat/hr at 1.0 MPa and 200 oC. The instruments XRD, SEM, EDS, H2-TPR, CO2-TPD, XPS, and contact angle were applied to evaluate the characteristics of catalysts and explain the activity test results. Chemical kinetic analysis was conducted based on the results obtained under different reaction conditions. Furthermore, a high-pressure reaction was carried out at the Industrial Technology Research Institute (ITRI) to confirm the excellent catalyst performance under industrial high-pressure operation, thus worth the further development of h-BN supported catalysts. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88212 |
DOI: | 10.6342/NTU202301646 |
全文授權: | 同意授權(限校園內公開) |
顯示於系所單位: | 化學工程學系 |
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