Research of gold catalysts loading on Al2O3-MOx (M=Cu, Mg, Zn) binary support applied to partial oxidation of methanol (POM) to produce hydrogen
| Autor: | Yu-Hsien Lin, 林祐賢 |
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| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 The effect of binary support of gold catalysts is widely studied. We prepare the binary support via impregnation method(Al2O3-MOx, M=Cu, Zn and Mn). The gold catalysts is then prepared by deposition -precipitation method (Au/Al2O3-MOx). The catalysts were characterized by ICP-AES, TGA, XRD, TEM, and XPS analyses. BET results shows that the surface area does not differ much from the choose of the binary support. ICP-AES results shows the surface property effect of the ability of absorption, Au/Al2O3-MnOx has the greatest gold loading amount. TEM images show that the size of gold decreases because of the binary support, about half compare to the single support catalysts, 4.97 nm after 473 K calcination, but still sintering to 11.6 nm after 673 K calcination. From XPS data, gold exists in metallic state. Selective production of hydrogen by partial oxidation of methanol (CH3OH + 1/2O2 → 2H2 + CO2) over Au/Al2O3-MnOx catalysts, the activity depends strongly on the supports, but also on the state of gold. The activity is better than single support catalysts apparently. It shows the good activity while it goes without calcination, we believe that it is because of the state of gold. Increasing the reaction temperature, the methanol conversion and hydrogen selectivity increase either. Binary supports could lower the condition of sintering and provide more active site. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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