超细ZrO_2催化剂的织构和晶相结构对合成甲醇、异丁醇的影响

RELATIONS BETWEEN ZrO 2 CRYSTAL STRUCTURE AND ITS CATALYTIC ACTIVITY TO METHANOL AND ISOBUTANOL

采用超临界干燥法制备ＺｒＯ２超细催化剂，用于一氧化碳加氢合成甲醇、异丁醇。考察了催化剂的焙烧温度、焙烧时间以及碱金属助剂对合成醇性能的影响，并结合Ｎ２吸附、ＴＥＭ、ＸＲＤ表征，研究催化剂的织构、体相结构与催化活性的关系。发现随着催化剂焙烧温度升高、焙烧时间的延长，ＺｒＯ２由四方晶型（ｔＺｒＯ２）向单斜晶型（ｍＺｒＯ２）转变；浸渍Ｋ２ＣＯ３在焙烧过程中能够稳定ｔＺｒＯ２，浸渍Ｎａ２ＣＯ３则促进四方晶型向单斜晶型的转变。微细颗粒四方晶型的ＺｒＯ２有利于异丁醇的生成。

Methanol and isobutanol were synthesized from syngas selectively over superfine zirconium oxide (ZrO 2) catalysts The effects of calcination temperature, time, and basic promoter on the catalytic activity were investigated K 2CO 3 could promote the synthesis of isobutanol and Na 2CO 3 promote the production of ethanol The best conditions for isobutanol were 420℃, 10 0MPa, 5000h 1 , when the weight percentage and space time yield of isobutanol could reach 16 33% (W) and 8 90ml/h·l, respectively In XRD patterns, almost of zirconia superfine aerogel powder was tetragonal phase (tZrO 2), which could be turned to monoclinicphase with the increasing temperature and time of calcination The tZrO 2 could be stablized when K 2CO 3 was introduced by impregnation method before calcination, while the Na 2CO 3 could promote the tZrO 2 turning to mZrO 2 The fine tZrO 2 favours the production of isobutanol