脱铝NaY沸石封装磷钨酸催化剂的制备、表征及催化性能评价

Preparation,characterization and catalytic performance evaluation of dealuminated NaY zeolite encapsulated phosphorotungstic acid catalyst

以脱铝改性的NaY分子筛为载体,利用原位合成法将磷钨酸封装进改性后的NaY牢笼内,制得一系列PW-DY催化剂。以油酸的转化率为指标,考察了催化剂对油酸酯化反应的催化性能影响,得出PW-DY催化剂的最佳制备条件,并对该条件下的催化剂进行了SEM-EDS、FT-IR、XRD表征。结果表明,当NaY改性时溶液体系的pH为3、钨酸钠的添加质量为0. 8g、磷酸化时间为6 h时,所得催化剂催化性能最优。在醇油摩尔比为20∶1、催化剂质量分数为4%、反应温度为110℃、反应时间6h的条件下,催化剂的油酸转化率可达64. 5%。

Using dealuminated NaY molecular sieve as carrier,a series of PW-DY catalysts are prepared through encapsulating phosphotungstic acid into dealuminated NaY cage by in situ synthesis method.Taking the conversion rate of oleic acid as an index,the effects of the catalysts on esterification of oleic acid are investigated,and the optimum preparation conditions of PW-DY catalysts are obtained.The catalysts are characterized by SEM-EDS,FT-IR and XRD.It is shown that the best catalytic performance can be given by the catalyst that are prepared under the following conditions:pH of the solution system is 3 when NaY is dealuminated,the adding amount of sodium tungstate is 0. 8 g and the phosphorylation process last for 6 h. The conversion rate of oleic acid can reach 64. 5% when the best catalyst is used with an adding content of 4%,the molar ratio of alcohol oil to oleic acid is 20 ∶1,reaction temperature maintains at 110℃and reaction spends 6 h.