偏硼酸钙改性Al-MCM-41催化剂的表征及催化性能

Characterization and Catalytic Performance of Calcium Metaborate Catalyst Supported on Al-MCM-41 in the Oxyethylation of n-Octyl Alcohol

通过微波加热的方法,将质量分数为20%的偏硼酸钙分散在Al-MCM-41（n（S i）∶n（Al）=30∶1）介孔分子筛上,得到Ca（BO2）2/Al-MCM-41分子筛催化剂。通过XRD、IR、NH3-TPD吸附脱附、BET及CCl4吸附等测试技术对催化剂的晶体结构和表面物性进行了研究。结果表明,通过微波辐射,偏硼酸钙已经分散到介孔分子筛的骨架结构中。Ca（BO2）2/Al-MCM-41用于催化正辛醇乙氧基化反应。结果表明,Ca（BO2）2/Al-MCM-41的催化活性较Ca（BO2）2及Al-MCM-41分子筛均有了较大的提高。正交实验结果表明,当Ca（BO2）2/Al-MCM-41催化剂占正辛醇的质量分数为5%,反应温度为140℃,初始压力为0.4-0.5 MPa,环氧乙烷（EO）平均加成数为6.4时,产品的分子量分布选择性系数Cs=17.9,环氧乙烷加和数为5、6和7组分的总收率均为51.9%,具有较好的窄分布效果。

Mesoporous molecular sieves containing aluminum ions（ Al-MCM-41 ） with Si/Al ratio of 30 were used to support 20% calcium metaborate （Ca （BO2）2） by microwave irradiation method. The samples, Ca （ BO2 ） 2/Al-MCM-41 were characterized by powder X-ray diffraction （XRD） , nitrogen adsorption measurement（BET）, Fourier transform infra red spectroscopy（FT-IR）. The XRD patterns show that the Ca（BO2）2 was dispersed uniformly on Al-MCM-41 and the material, Ca （BO2 ）2/Al-MCM-41, had the indigenous Al-MCM-41 structure and ordered pore distribution. Ca（ BO2） 2/Al-MCM-41 samples were used as catalysts in the ethyloxylation of n-octyl alcohol. The results show that Ca（ BO2 ）2/Al-MCM-41 has higher catalytic activity than Al-MCM-41 and Ca（BO2） 2- The reaction was carried out at 140 ℃ in the presence of 5% catalyst with respect to the octanol. The homologue distribution of the ethoxylates was determined by means of GC and MS techniques, which showed the homologue distribution of octanolpolyoxyethylene ethers was narrowed for Ca（ BO2 ） /Al-MCM-41 catalyzed ethoxylation, and the selectivity coefficient（ Cs） was 17.9.