本研究利用化學法(Chemical Method)將二氧化鈦製備成二氧化 鈦奈米管，比較不同鍛燒溫度對奈米管的成型與表面積的影響，並利 用沉澱固著法(Deposition Precipitation)和初濕含浸法將二氧化鈦擔載 金觸媒；利用光化學沉積法和沉澱固著法製備鉑觸媒，以不同晶相及 不同表面積的二氧化鈦擔載金屬觸媒在紫外光照射下進行甲醇重組 反應產生氫氣。利用XRD、TEM、BET 等不同鑑定方法分析所合成 的二氧化鈦奈米管之結構與表面積，並探討擔載金、鉑觸媒的反應特 性及觸媒活性。 結果顯示，化學法製備的二氧化鈦奈米管管外徑約12 奈米，內 徑8 奈米，長約數百奈米。沉澱固著法製備的二氧化鈦擔載金觸媒， 金顆粒呈半圓球型，顆粒大小約4~7 奈米，沉積於擔體表面或奈米管 中，而初濕含浸法製備的金觸媒其金顆粒大小分佈較為不均。比較光 化學沉積法與沉澱固著法製備的白金觸媒，發現光化學沉積法製備的 鉑觸媒，其擔體上的白金顆粒較沉澱固著法小。活性測試顯示，金觸 媒活性隨鍛燒溫度升高而降低，其中以200℃鍛燒後的金觸媒活性最 佳。而沉澱固著法製備的觸媒反應活性較初濕含浸法製備的觸媒好。 白金觸媒對甲醇重組產氫也有與金觸媒相同的效果，金屬顆粒越小將 會有越好的反應活性。 Titanium nanotubes were prepared from titanium powers by treating with 10 M NaOH at 110~130℃ for 24 hours(Chemical method). Excess NaOH was then neutralized with distilled water and HCl(aq). The TiO2 nanotubes were characterized by X-ray diffraction (XRD), specific surface area (BET), and transmission election microscope (TEM). Then we prepare Au/TiO2, Pt/TiO2 by deposition precipitation and incipient wetness methods. And we prepare Pt/TiO2 by photochemical deposition method. We can evaluate the activities of these catalysts by hydrogen production of methanol reforming under ultraviolet light (350nm) irradiation. We use XRD, BET, and TEM to analyze various catalysts. The TiO2 nanotubes were prepared by chemical method with inner diameters of approximately 8 nm and outer diameters 12nm and 100 nm lengths. The gold on the surface of TiO2 by deposition precipitation method is hemisphere and the Au particles size is 4~7 nm. And we use photochemical deposition method to prepare Pt/TiO2, the Pt particles size is about 1nm. When Au/TiO2 and Pt/TiO2 were calcined at higher temperature the particles size gets bigger. The catalytic activity is strongly dependent on the gold and platinum particles size, the smaller particles produces higher amount of hydrogen.
