MgAPO-5／MCM-41分子筛的表征及催化性能

CHARACTERIZATION AND CATALYTIC PERFORMANCE OF MgAPO-5/MCM-41 MOLECULAR SIEVE

采用微波水热法合成了MgAPO-5/MCM-41分子筛。考察了晶化温度对分子筛合成和性质的影响,并通过XRD、NH_3-TPD、TEM、NMR等分析手段对合成的样品进行了表征。结果表明,当晶化温度为90℃时,合成的样品具有微孔结构和MCM-41特有的六方排列的孔道结构,P原子和Al原子都进入了分子筛的骨架,并且具有较高的有序度、比表面积、孔容和平均孔径。Mg的掺入能显著提高分子筛的酸性。用MgAPO-5/MCM-41分子筛催化苯与α-十二烯的烷基化反应时,α-十二烯的转化率可达到99%以上,2-苯基十二烷的选择性达到20%以上,但该分子筛稳定性不高。

MgAPO-5/MCM-41 was synthesized by microwave hydrothermal crystallization process and characterized by XRD, NH3-TPD, TEM and NMR. The effects of crystallization temperature on the synthesis and properties of MgAPO-5/MCM-41 were investigated and discussed. The synthesized samples possessed micro-pore structure and regularly hexagonal pore arrangement when the crystallization temperature was 90℃, and high specific area, pore volume and average pore diameter. Phosphorus and aluminum atoms were successfully incorporated into the framework of the synthesized samples. Besides, the acid amount could be improved greatly by the addition of Mg. The catalytic activity of MgAPO 5/MCM-41 was measured by alkylation reaction of benzene and dodecene-1. It was found that the conversion of dodecene 1 was more than 99% and the selectivity of 2-phenyldodecane was more than 20%. However, the stability for the activity of MgAPO-5/MCM-41 was bad.