儲存環境(光、真空、容器)對Au/TiO2之影響

Effects of Storage Conditions(light, vacuum and container) on Au/TiO2

梁凱惠(Kai-Hui Liang)

指導教授 ： 萬本儒

國立臺灣大學/工學院/化學工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.02155

摘要

為探討Au/TiO2觸媒受到光、容器和真空等儲存條件的影響，觸媒樣品被儲存在室溫中不同條件下，並以0℃一氧化碳氧化反應測試其活性，以及使用AA,H2-TPR,HR-TEM,XPS和FT-IR作為鑑定工具。結果顯示光會使金顆粒聚集而使觸媒活性衰退。Au/TiO2觸媒活性亦會受到儲存容器材質的影響，在玻璃瓶中儲存的觸媒維持很高的活性，而高密度聚乙烯(HDPE)瓶和聚乙烯(PE)夾鍊袋則都會使觸媒活性衰退且造成金的還原，其中又以聚乙烯(PE)夾鏈袋的影響遠為顯著。此外，不論照光與否或容器的改變，儲存在真空中的Au/TiO2觸媒都有極為明顯的衰退。這衰退很可能是由於金與鈦之間的作用力變強所造成，因為真空儲存的觸媒都有明顯較高的金還原溫度、較小的金顆粒以及稍高的金鍵結能(Binding energy)。因此，在本研究中建議最有效儲存Au/TiO2觸媒的方式為將其儲存在大氣下、黑暗中，並使用不會和金觸媒互相作用的容器材質(如：玻璃瓶)。在此儲存條件下，Au/TiO2觸媒可維持長達兩年以上的高活性。

關鍵字

金觸媒 ； 儲存 ； 活性衰退

並列摘要

Several Au/TiO2 catalysts were stored in various conditions at room temperature to determine how their catalytic activity was affected by light, container and vacuum during the storage and which might be the best condition for the storage of Au/TiO2 catalysts by conducting CO oxidation at 0℃. The samples were also characterized by H2-TPR, HR-TEM, XPS and FT-IR. The results showed that light might cause decay of the catalytic activity of Au/TiO2 due to gold agglomeration. The activity of Au/TiO2 was also affected by the material of the container. Catalysts stored in glass vials maintained high activity. However, HDPE bottle and PE bag both caused deactivation of catalyst and reduction of gold, and the influence of the latter was far more significant than that of the former. Moreover, the catalytic activity of Au/TiO2 stored under vacuum decayed substantially, regardless of the variations in light and container. The deactivation might be due to stronger interaction between gold and titanium, since the vacuum samples all had higher gold reduction temperature, smaller gold particle size and higher Au binding energy. Hence, the most effective way to store Au/TiO2 catalysts suggested in this study is to store Au/TiO2 catalysts in atmosphere in the dark, and in containers which would not and interact with Au/TiO2 such as glass vials. Under the condition, the catalyst could maintain high activity for at least 2 years.

並列關鍵字

Au/TiO2 ； Storage ； Deactivation

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