制备方法对Al2O3掺杂Pt/WO3-ZrO2催化剂上正庚烷异构化反应的影响  

Influence of preparative method on Al_2O_3-doped Pt/WO_3-ZrO_2 catalyst for n-heptane isomerization

作　　者：尚书宁[1] 徐欣[1] 谢鹏飞[1] 乐英红[1] 华伟明[1] 高滋[1] 

机构地区：[1]复旦大学化学系上海市分子催化和功能材料重点实验室,上海200433

出　　处：《催化学报》2013年第5期898-905,共8页

基　　金：国家自然科学基金(20633030,20773027,21273043);高等学校博士学科点专项科研基金(20100071110008);上海市科学技术委员会项目(08DZ2270500)~~

摘　　要：采用恒pH法和非恒pH法制备了Al2O3掺杂的Pt/WO3/ZrO2催化剂,并用N2吸附-脱附、X射线衍射、紫外-可见漫反射、CO化学吸附、X射线光电子能谱、27Al魔角旋转核磁共振和吡啶吸附红外等技术对催化剂进行了表征.结果表明,相比于非恒pH法制备的催化剂,恒pH法制备的催化剂具有较高的比表面积和Pt分散度,在H2气氛中产生更多的B酸位,从而表现出更高的催化正庚烷临氢异构化反应活性;在200oC和质量空速0.9h1的反应条件下,正庚烷转化率达70.0%,明显高于非恒pH法制备的催化剂(43.5%).Alumina-doped Pt/WO3/ZrO2 catalysts were prepared using either a constant or variable pH meth-od. The obtained catalyst samples were characterized using N2 adsorption, X-ray diffraction, ultra-violet-visible diffuse reflectance, CO chemisorption, X-ray photoelectron spectroscopy, 27Al mag-ic-angle spinning nuclear magnetic resonance, and infrared spectroscopy of adsorbed pyridine. Compared to the catalyst prepared using the variable pH method, the catalyst prepared using the constant pH method had a higher surface area and Pt dispersion. More Br nsted acid sites were generated in the presence of H2 on the latter catalyst, and this was responsible for its higher catalyt-ic activity in n-heptane hydroisomerization. When the reaction temperature was 200 °C and the weight hourly space velocity of n-heptane was 0.9 h–1, the Pt/WO3/Al2O3-ZrO2 catalyst prepared using the constant pH method gave 70.0% conversion of n-heptane, which was significantly greater than the conversion obtained using the corresponding catalyst prepared using the variable pH method (43.5%).

关 键 词：铂 氧化钨 氧化锆 氧化铝掺杂 制备方法 正庚烷临氢异构化 质子酸位 

分 类 号：O643.32[理学—物理化学]