微波辐射下Zn-X、Zn-Y和Zn-丝光沸石催化剂的制备

Preparation of Zn^(2+)-Zeolites Using Microwave Irradiation

利用微波辐射加热进行Zn2+离子与X、Y和丝光沸石分子筛的离子交换,制备离子交换型沸石催化剂Zn-X、Zn-Y和Zn-丝光沸石.通过考察溶液浓度、微波辐射功率、加热时间等因素对交换度的影响,得出交换反应的适宜工艺条件为:交换原液浓度0.06 mol.L-1(丝光沸石)、0.10mol.L-1(Y沸石)、0.12 mol.L-1(X沸石),加热时间6 min(X沸石和Y沸石)、12 min(丝光沸石),微波辐射功率390 W(X沸石、Y沸石和丝光沸石).Zn2+离子与X、Y和丝光沸石的一次交换度分别为79.2%(X沸石)、67.7%(Y沸石)3、8.8%(丝光沸石).对比实验结果表明:在相同工艺条件下,微波辐射加热法所需时间仅为传统加热法的1/40~1/80.XRD结果表明:微波辐射对沸石晶体结构无破坏作用.采用“二交二焙”法可使Zn2+与Y沸石的交换度由67.7%提高到79.2%.

It was investigated that the cation exchange of Zn^2＋ with zeolites X, Y and mordenite under the heating of microwave radiation and the effects of cation concentration （ c ）, heating （ t ）, microwave power（P） on the exchange degrees. The results showed that the exchange degrees of the cation in zeolites can reach 79.2 % （X）, 67.7 % （Y） and 38.8 % （mordinite） by one-step exchanging, respectively. The proper operation conditions were as follows： microwave power 390 W, the original concentration of Zn^2＋ were 0.06 mol·L^-1（mordenite） 0.10 mol·L^-1（Y） ,0.12mol·L^-1（X） ; heating time were 6 min （X and Y）, 12 min（mordenite）. Comparing with conventional heating method, the heating time using microwave radiation technique was 1/40-1/80 of the former. Microwave radiation did not destroy the crystal structure of zeolite X,Y and mordenite. The exchange degree can enhance to 79.2 % （zeolite Y） by using the ＂2-exchange-2-calcine＂ method.