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本文用12-磷钨酸(HPW)及其钠盐(NaPW)作为转化乙醇为乙醚的固体催化剂,研究了不同的载体及制备方法对催化活性的影响,应用红外光谱法、BET容量法、BET重量法和热重量分析法考察催化剂的性质,初步探讨了活性与催化剂性质之间的联系. 1.催化剂制备所用HPW为分析纯试剂,钠盐是由Na_2CO_2中和HPW所得.分别用浸渍法和圆流吸附法制备样品.载体硅胶经酸处理后于500℃焙烧2小时,按10ml硅胶担载5×10~(-3)mol HPW的比例,将硅胶在HPW水溶液中浸渍24小时,烘干后在300℃焙烧2小时得HPW/硅胶催化剂.经水充分洗过的活性炭在100℃烘6小时,然后置于HPW或NaPW水溶液(溶液的浓度按每克活性炭担载0.18克HPW的比例配制)中加热回流1小时,冷却后抽滤洗涤至中性,于50℃烘干得HPW/活性炭催化剂或NaPW/活性炭催化剂.
In this paper, 12-phosphotungstic acid (HPW) and its sodium salt (NaPW) were used as solid catalysts for the conversion of ethanol to ethyl ether. The effects of different supports and preparation methods on the catalytic activity were studied. Gravimetric method and thermogravimetric method were used to investigate the properties of the catalyst and the relationship between the activity and the properties of the catalyst was discussed preliminarily.1.The HPW used in the preparation of the catalyst was an analytical reagent and the sodium salt was obtained by neutralizing HPW with Na_2CO_2, The samples were prepared by the round flow adsorption method.The silica gel was acid-treated and then calcined at 500 ℃ for 2 hours. The silica gel was immersed in HPW aqueous solution for 24 hours according to the proportion of 10 × silica gel supporting 5 × 10 -3 mol HPW. And calcined at 300 ° C. for 2 hours to obtain HPW / silica gel catalyst. The activated carbon thoroughly washed with water was baked at 100 ° C. for 6 hours and then placed in HPW or NaPW aqueous solution (the concentration of the solution was 0.18 g HPW per gram of activated carbon ) Was heated to reflux for 1 hour, cooled and filtered to neutral washing, drying at 50 ℃ HPW / activated carbon catalyst or NaPW / activated carbon catalyst.