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通过溶胶凝胶法与阳极氧化铝模板法(AAO)相结合来可控合成La_2O_3/AAO纳米阵列催化剂,以丙酮缩合制备二丙酮醇为探针反应考察了催化剂的催化性能。采用XRD、SEM、TEM、BET和CO2-TPD对催化剂进行了表征。结果表明,催化剂活性组分La_2O_3在AAO模板上分散均匀,当焙烧温度为900℃,焙烧时间为1 h时,反应时间3 h,催化剂活性达到最佳,此时丙酮转化率为4.01%,二丙酮醇选择性为96.32%。催化剂重复使用5次后,丙酮转化率为3.63%,二丙酮醇选择性为97.06%。La_2O_3/AAO-900催化剂具有较大的比表面积和较强的弱碱性位是其活性高的主要原因。
The La 2 O 3 / AAO nanoarray catalyst was synthesized by sol-gel method combined with anodic alumina template (AAO) method. The catalytic performance of the catalyst was investigated by acetone condensation of diacetone alcohol as a probe reaction. The catalysts were characterized by XRD, SEM, TEM, BET and CO2-TPD. The results showed that the active component La_2O_3 was uniformly dispersed on the AAO template. When the calcination temperature was 900 ℃ and the calcination time was 1 h, the reaction time was 3 h, and the activity of the catalyst was the best. At this time, the conversion of acetone was 4.01% The acetol selectivity was 96.32%. After repeated use of the catalyst for 5 times, the acetone conversion was 3.63% and diacetone alcohol selectivity was 97.06%. La2O3 / AAO-900 catalyst has a large specific surface area and strong weak alkaline sites are the main reasons for its high activity.