Synthesis and characterization of chromia-pillared layered tetratitanate  

作　　者：侯文华 陈亚芍 郭灿雄 颜其洁 陈懿 陈静 

机构地区：[1]Department of Chemistry, Nanjing University, Nanjing, Jiangsu 210093, China [2]Department of Applied Chemistry, Nanjing University of Chemical Technology, Nanjing, Jiangsu 210008, China

出　　处：《Chinese Journal of Chemistry》1999年第2期142-149,共8页中国化学（英文版）

基　　金：Project (No. 29573108) supported by the National Natural Science Foundation of China

摘　　要：The first chromia-pillared layered tetratitanate was prepared by the reaction of layered tetramethylammonium tetratitanate with chromium (III) acetate [Cr(OAc)3] aqueous solution and subsequent calcination of the resultant solid product in air at 400°C. The obtained chromia-pillared layered tetratitanate has an interlayer distance of 1.06 nm and a high thermal stability up to 600°C. It was also found that calcination in N2 led to the chromia-pillared layered tetratitanate with relatively higher Brunauer-Emmett-Teller (BET) specific surface area (93.9 m2·g?1) and smaller average pore diameter (4.44 nm) than that in air (82.0 m2·g?1, 7.61 nm). Both Br?nsted and Lewis acid sites (mainly Lewis type) are present on the chromia-Pillared layered tetratitanate (500°C, N2, 8 h) and strong enough to still remain a small proportion of pyridine upon outgassing at 250°C. Moreover, ammonia temperature-programmed desorption (NH3-TPD) result showed that there were three NH3 desorption peaks at 160, 200 and 315°C, respectively. The corresponding acid amount is 41.3, 73.9 and 290.7 μmol·g?1. The total acid amount is 405.9 μmol·g?1.The first chromia-pillared layered tetratitanate was prepared by the reaction of layered tetramethylammonium tetratitanate with chromium (III) acetate [Cr(OAc)3] aqueous solution and subsequent calcination of the resultant solid product in air at 400°C. The obtained chromia-pillared layered tetratitanate has an interlayer distance of 1.06 nm and a high thermal stability up to 600°C. It was also found that calcination in N2 led to the chromia-pillared layered tetratitanate with relatively higher Brunauer-Emmett-Teller (BET) specific surface area (93.9 m2·g?1) and smaller average pore diameter (4.44 nm) than that in air (82.0 m2·g?1, 7.61 nm). Both Br?nsted and Lewis acid sites (mainly Lewis type) are present on the chromia-Pillared layered tetratitanate (500°C, N2, 8 h) and strong enough to still remain a small proportion of pyridine upon outgassing at 250°C. Moreover, ammonia temperature-programmed desorption (NH3-TPD) result showed that there were three NH3 desorption peaks at 160, 200 and 315°C, respectively. The corresponding acid amount is 41.3, 73.9 and 290.7 μmol·g?1. The total acid amount is 405.9 μmol·g?1.

关 键 词：Layered tetratitanate CHROMIA PILLARING 

分 类 号：O614[理学—无机化学]