Chen Yang, Yan Dongpeng, Song Yu-Fei
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
Dalton Trans. 2014 Oct 21;43(39):14570-6. doi: 10.1039/c4dt01827c.
Polyoxometalate (POM) intercalation to layered double hydroxides (LDHs) has been greatly restricted by the geometry, charge and size of POMs. We report herein, for the first time, the intercalation of Na3[PW12O40]·15H2O into tris(hydroxymethyl)-aminomethane (Tris) modified layered double hydroxides (Tris-LDH-CO3) using an ion exchange method, resulting in the formation of novel intercalated Tris-LDH-PW12 under ambient conditions without the necessity of degassing CO2. Theoretical calculations show the decreased energy and the slightly distorted LDH layer after Tris modification, indicating that the Tris-modified LDH layers greatly facilitate the intercalation of PW12. Further application of Tris-LDH-PW12 for oxygenation of sulfides shows highly efficient and selective catalytic activities under mild conditions. The Tris-LDH-PW12 can be easily recovered and reused for more than 10 times without any obvious decrease of reactivity. This opens a completely new pathway for engineering POM-LDH advanced functional materials.
多金属氧酸盐(POM)插入层状双氢氧化物(LDH)受到POM的几何结构、电荷和尺寸的极大限制。我们在此首次报道,使用离子交换法将Na3[PW12O40]·15H2O插入三(羟甲基)氨基甲烷(Tris)修饰的层状双氢氧化物(Tris-LDH-CO3)中,在环境条件下形成了新型插层的Tris-LDH-PW12,无需脱除二氧化碳。理论计算表明,Tris修饰后能量降低且LDH层略有扭曲,这表明Tris修饰的LDH层极大地促进了PW12的插入。Tris-LDH-PW12在硫化物氧化中的进一步应用表明,在温和条件下具有高效和选择性催化活性。Tris-LDH-PW12可以很容易地回收并重复使用10次以上,而反应活性没有任何明显下降。这为设计POM-LDH先进功能材料开辟了一条全新的途径。