Preparation, characterization and catalytic application of tungsten oxide/carbon nanotube composite

• Main Authors: Ci-hsun Kuo, 郭啟訓
• Other Authors: J.-R. Chang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/02799578895414913833

碩士 === 國立中正大學 === 化學工程所 === 95 === In this study, WCx/CNT composite was synthesized from WO3 and carbon nanotubes (CNT) by carbothermal reduction reaction. To study the selectivity and the conversion in the partial oxidation of alcohol, two processes, temperature-programmed oxidation and addition of sulfides, were carried out with various sample on the support. After carbothermal reduction reaction, the WC/W2C/CNT (WCx/CNT) was obtained and the particle size of WCx was about 10 nm. In temperature-programmed oxidation, WCx/CNT, WOx/CNT and WOx were prepared at 500, 600 and 800 ℃, respectively. Additionally, the sample color turned from black to light yellow as increasing oxidized temperature. On the other hand, WCx/CNT was impregnated in Ammoniumm sulfate to increasing the sulfur content. When we carried out the alcoholic partial oxidation reaction with WOx/CNT as catalyst, we got higher conversion (30–50%) and generated more ethyl ether than that with a commercial WO3. And, when we used S/WOx/CNT as catalyst, we got more acetaldehyde than S/WCx/CNT as catalyst, because S/WOx/CNT has more oxide group. On the contrary, using S/WCx/CNT as catalyst produced more ethyl acetate due to relatively strong Lewis acid.