镁铝物质的量之比对水滑石纳米材料及其催化性能的影响  

Effect of Molar Ratio of Mg to AI on Hydrotalcite Nanomaterials and Catalytic Performance

作　　者：杨永杰[1] 曾虹燕[1] 王亚举[1] 赵策[1] 魏英民[1] 刘平乐[1] 

机构地区：[1]湘潭大学化工学院生物技术研究所,湖南湘潭411105

出　　处：《化学反应工程与工艺》2011年第4期358-362,共5页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金(20976148);湖南省教育厅科学研究重点项目(08A080)

摘　　要：采用尿素法制备不同镁铝比的水滑石,利用X射线衍射(XRD)、傅立叶红外光谱(FT-IR)、扫描电镜(SEM)、能谱仪(EDS)和低温N_2吸附技术(BET)等对水滑石进行表征,探讨了镁铝物质的量之比对水滑石晶体结晶度的影响。以合成丙二醇甲醚的反应为探针,考察了不同镁铝比对水滑石氧化物催化性能的影响。结果表明,水滑石的结晶度和其煅烧物的催化性能受镁铝比影响较大。镁铝物质的量之比为4:1的水滑石具有高结晶度的六边形层状或片状结构,晶粒均匀,孔径大、分布窄,其煅烧物在合成丙二醇甲醚反应中具有较好的催化活性和稳定性,环氧丙烷转化率和丙二醇单甲醚选择性分别达到92.7%和97.4%,循环使用5次后催化性能依然稳定。Mg-AI hydrotalcites with different molar ratio of Mg to AI were prepared and characterized by X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, energy disperse spectroscopy（EDS） and low-temperature nitrogen adsorption-desorption technique （BET）. The effect of molar ratio of Mg to AI on the crystalline of hydrotalcite and the catalytic performance of the calcined hydrotalcites in synthesis of propylene glycol methyl ether（PM） were investigated. The results showed that the crystalline of hydrotalcites and the catalytic performance of the calcined hydrotalcites were related to the molar ratio of Mg to AI. The hydrotalcites with molar ratio of Mg to AI 4 had high crystalline with symmetrical hexagon fiat crystals and narrow range large pore size distribution. The calcined hydrotalcite exhibited high catalytic activity and stability, and the propylene oxide（PO） conversion and PM selectivity were 93.2% and 97.4%, respectively. The catalytic performance was stable after being reused five times.

关 键 词：水滑石 尿素法 丙烷 甲醇 丙二醇甲醚 

分 类 号：TQ132.2[化学工程—无机化工] TQ133.1