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采用共沉淀法制备复合催化剂Zr O2-Ti O2,对其晶体形态、形貌、比表面积、孔性质、酸性质进行了表征,考察了其对柠檬酸与正丁醇酯化反应的催化性能.结果表明,复合物中Zr O2含量为25%(ω)时,Zr O2-Ti O2呈无定型形态,比表面积为239.6m2/g,兼具B酸和L酸,NH3吸附量为670μmol/g.25%Zr O2-Ti O2对柠檬酸与正丁醇酯化反应催化效果最好,柠檬酸转化率最大,为96.6%,柠檬酸正三丁酯的选择性为98.2%,适宜的反应条件为反应温度115℃,反应时间90 min,反应5次后柠檬酸转化率保持80%以上,柠檬酸三丁酯选择性约为98%.
The composite catalyst Zr O2-Ti O2 was prepared by co-precipitation method. Its crystal morphology, morphology, specific surface area, pore properties and acidity were characterized. The catalytic performance of the esterification reaction between citric acid and n-butanol was investigated. The results showed that the ZrO2-TiO2 was amorphous when the content of ZrO2 in the composite was 25% (w). The specific surface area was 239.6m2 / g, with both B acid and L acid. The adsorption capacity of NH3 was 670μmol / g .25% Zr O2-Ti O2 catalyzed the esterification of citric acid with n-butanol, with the highest conversion of citric acid of 96.6% and the selectivity of n-tributyl citrate of 98.2%. The suitable reaction conditions were The reaction temperature was 115 ℃ and the reaction time was 90 min. After 5 times of reaction, the conversion of citric acid was above 80% and the selectivity of tributyl citrate was about 98%.