A Study on the Supported CuO-ZnO Catalystsfor Producing Hydrogen by Steam Reforming of Methanol

• Main Authors: Shi-Wei Yan, 顏世偉
• Other Authors: Hung-Shan Weng
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/47851184112265846138

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 92 === This is a study on producing hydrogen by steam reforming of methanol. We choose several suitable catalysts for the reaction, and measuring the basic physical properties and chemical properties of these catalysts through the use of XRD,TPR,BET,SEM. Subsequently, with controlling the experimental condition ,S/C（steam-to-methanol mole ratio）equal to 1.5 ,O/C（oxygen-to-methanol mole ratio）=0.3, and the reaction temperature=300 ℃, we determining the methanol conversion, the rate of hydrogen generation, and the concentration of the side product, carbon monoxide, and we can comprehend the performances of these catalysts thus. First of all, we prepare γ-Alumina-supported catalysts which containing different CuO-ZnO ratios, and measure the activities of these samples. We found that all the catalysts have similar activity except ZnO/γ-Al2O3 catalyst which has bad activity. However, using the catalyst containing active component CuO-ZnO （1：1）as sample, the result shows a low CO concentration. Furthemore, fixing the CuO-ZnO ratio at 1：1, and supports it by CeO2 ,SDC（Samarium-Doped Ceria）, we found that, although the SDC has a lower conversion, it has a better effect of restraining CO generation. We conjecture that the result is due to SDC surface offer stable oxygen vacancies, and these oxygen vacancies enhance the oxidization of CO. Subsequently, Changing the reaction temperature of CuZn11/SDC（active component CuO：ZnO =1：1, supported on SDC）, the methanol conversion reach 60 % at 200℃, and CO concentration is merely 2 %. In addition, Changing the reduction condition before reaction, and testing the stability by a long time, we found that, these changes will not influence activity too much. Therefore, we deduce that the Fluorite-type structure is not only conducive to anti-sintering, but promoting the metal dispersion. If our objective is getting low CO concentration at low temperature, and having a well conversion（60%）simultaneously, CuZn11/SDC has best performance at 200 ℃.