金屬氧化物觸媒之界面物理性質之研究

A Study on Surface Physical Properties of Metallic Oxide Catalysts

施鑑洲(Chien-Chou Shih)

《化學》 55年3期 (1966/09) Pp. 85-98

https://doi.org/10.6623/chem.1966013

摘要

以SiO_2-AI_2O_3-CrO_3類觸媒為主，變化各種處理條件，使其具有不同之界面物理性質，而探究其界面物理性質與各種處理條件，活化條件以及活性問之相互關係。以SiO_2-AI_2O_3為擔體之CrO_3類觸媒於0℃吸附正丁烷時所得之吸附等溫曲線屬於第IV種形狀之曲線。共同沉澱法所調製之矽鋁膠（SiO_2-AI_2O_3 gel）擔體，其界面物理性質受處理過程中各種因素之影響至大。其細孔總容積及平均細孔半徑均隨pH值與膠化溫度之增高，靜置時間之延長，焙燒溫度之降低及AI_2O_3含量之增加而有增大之趨勢，但表面積則除於焙燒溫度減低時反而增大外，其他情形均呈減少之現象。彼等表面積多在82～240m^2/g.（正丁烷，0°C）之間，細孔總容積在0.063～0.724cc./g.之間，其平均細孔半徑則為14～160Å。含浸法或共同沉澱法所製之SiO_2-AI_2O_3-CrO_3類觸媒活化時，以0.1l/g. cat /min. 流速之乾燥空氣在500°C處理5小時為佳。各種SiO_2-AI_2O_3-CrO_3類觸媒之界面物理性質及三氧化鉻含量與其活性有密切關係。即細孔總容積或三氧化鉻含量增大，丙烯聚合物之總收率即隨之有增大之趨勢。增加三氧化鉻之含量，增大平均細孔半徑及減小表面積將有助於增加丙烯高分子聚合物之收率。

並列摘要

The relations between the surface physical properties of SiO_2-Al_2O_3-CrO_3 catalysts or SiO_2-Al_2O_3 carriers and various treating conditions and the activity of polymerization of propylene are studied. The adsorption isotherms for n-butane on SiO_2-Al_2O_3-CrO_3 catalysts belong to the contour of type IV. The surface physical properties of SiO_2-Al_2O_3 gel carriers are greatly affected by various treating conditions in co-precipitate method. The total pore volume and the average pore radius increase with increasing pH value, gelation temperature, aging time, and Al_2O_3 content and with decreasing the calcinating temperature. The surface area decreases with increasing pH value, gelation temperature, aging time, Al_2O_3 content and calcinating temperature. The surface area of these carriers is 82 to 240 m^2/g, the total pore volume is 0.063 to 0.724 cc./g, and the average pore radius is 14 to 160Å. T he better conditions of activation are obtained by treating impregnated or co-precipitated SiO_2-Al_2O_3-CrO_3 catalysts with drying air at a velocity of 0.1 l/g. cat./min. and 500°C for 5 hours. The activity of SiO_2-Al_2O_3-CrO_3 catalyst has close relation to their surface physical properties and the CrO_3 content. The total yield of propylene polymer increases with increasing total pore volume and CrO_3 content. Higher yield of high polymer of propylene may be obtained by increasing average pore radius and CrO_3 content and decreasing surface area.