纳米Beta分子筛催化合成聚甲氧基二甲醚

Synthesis of polyoxymethylene dimethyl ether on nanocrystalline Beta zeolite

针对纳米分子筛粒径小、孔道短、比表面积大等优势,将纳米Beta分子筛用于催化合成聚甲氧基二甲醚(PODE_n,n为聚合度),并与常规Beta分子筛进行活性对比。实验结果表明,纳米Beta分子筛的活性明显优于常规Beta分子筛,低温条件下尤为突出;当整个反应体系达到平衡时,PODE_(3-5)的收率达到极值。纳米Beta分子筛合成PODE_n的工艺优化结果为:甲缩醛与甲醛摩尔比2∶3、反应温度35℃、反应时间30 min,自生压力的条件下,PODE_(3-5)收率最高可达62.26%。

Nanocrystalline zeolite has many advantages,such as small particle size,short channel and large specific surface area.Nano Beta zeolite was used to synthesize polyoxymethylene dimethyl ether(PODEn),and its activity was compared with that of conventional Beta zeolite.The results showed that the catalytic activity of nano Beta zeolite was better than that of the conventional Beta zeolite,especially at low temperature.When the whole reaction system reached equilibrium,the yield of PODE3-5 reached the extreme value.In addition,the results of technological conditions for synthesis of PODEn showed that under the conditions of the molar ratio of dimethoxymethane to methanal 2∶3,the reaction temperature 35℃,the reaction time 30 min and autogenic pressure,the yield of PODE3-5 reached up to 62.26%.