α．β-不飽和醛是一具有共軛C=C/C=O 鍵的化合物，其選擇性氫化被廣用於製藥、香料工業。以單一金屬觸媒進行氫化反應時，大多傾向於優先氫化C=C 鍵生成飽和醛，以往研究者大多以鉑金屬為研究對象，添加鐵或錫為促進劑，使用雙金屬觸媒，或是將鉑負載於TiO2 經過高溫還原，形成SMSI 效應，藉以提升觸媒對 C=O 鍵的選擇性氫化能力。近年來研究者將金負載於Fe2O3、Al2O3、ZrO2 等擔體上，發現可用於C=O 鍵的選擇性氫化，得到不錯的選擇性氫化效果，但缺乏深入的探討與機理的論述。吾人曾以MgAlO 鹼性擔體克服等電位點在6~8 的限制，製得CO 氧化反應高活性觸媒2%Au/Mg2AlO，且在檸檬醛選擇性氫化反應測試中，發現觸媒不但具高選擇性，且活性較文獻報導的Au 金觸媒高出許多。由於α．β-不飽和醛液相選擇性氫化不同於一般CO 氧化反應，因此本研究將有系統探討Au/MgxAlO 觸媒於α．β-不飽和醛之選擇性氫化。本研究擬分三階段進行，第一年：本研究以共沉澱法製備不同Mg/Al 比例的MgxAlO-hydrotalcite，經不同溫度煅燒後做為製備金觸媒的擔體， 並以調整後的沉澱沉積法製備 Au/MgxAlO 金觸媒，有系統地以肉桂醛選擇性氫化反應探討製備變因對金觸媒活性的影響；以最佳製備條件之觸媒探討反應溫度、反應總壓、反應溶劑及不飽和醛分子立體障礙對催化活性與選擇率之影響; 觀察C=C/C=O 共軛官能基，與 C=C、C=O 單一官能基氫化活性之差異，並與傳統觸媒詳細比較，藉以瞭解金觸媒於α．β-不飽和醛選擇氫化特殊催化行為的機理。第二年：探討不同擔體於金觸媒對α．β-不飽和醛擇性氫化的影響，藉以整合金觸媒於α．β-不飽和醛選擇性氫化的觀點。第三年：挑戰較難選擇氫化的巴豆醛，探討擔體、促進劑、金負載量、溫度、反應壓力、反應溶劑對催化活性與不飽和醇選擇率之影響，以期設計出適用於巴豆醛選擇氫化的理想金觸媒。α．β-unsaturated aldehydes are multi-unsaturated compounds that contain a pair of conjugated C=C/C=O bonds. The selective hydrogenation of α．β-unsaturated aldehydes is a critival step in the production of fine chemicals such as flavor and fragrance compounds and pharmaceuticals. The unsaturated alcohol is the desired products, but over most nonpromoted Group VIII metals the saturated aldehydes is selectively formed. The investigators used the platinum doped with promoters (Fe, Sn, etc.) or supported on easily reducible oxides (SMSI effect), or bimetallic catalysts to enhance the hydrogenation of the conjugated C=O bond. Gold supported catalysts are good candidates for the selective hydrogenation of the coniugated C=O bond. Among these studies on the liquid-phase hydrogenations over gold catalysts, only Fe2O3, hematite, TiO2, ZnO2 and Al2O3 were used as supports. A modified DP method was developed by us to obtain an active gold catalyst supported on MgxAlO-hydrotalcite for CO oxidation at low temperatures. 2%Au/Mg2AlO catalyst was explored on the hydrogenation of citral, and exhibited better performance than other gold catalysts reported. In this study, Au/MgxAlO catalysts will be systematically studied on the selective hydrogenation of α．β-unsaturated aldehydes to unsaturated alcohol. 研究期間 : 9808 ~ 9907
