Ide Yusuke, Tominaka Satoshi, Kono Hiroyuki, Ram Rahul, Machida Akihiko, Tsunoji Nao
International Center for Materials Nanoarchitectonics (MANA) , National Institute for Materials Science , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan . Email:
Department of Earth Sciences , Waseda University , 1-6-1 Nishiwaseda , Shinjuku-ku , Tokyo 165-8050 , Japan.
Chem Sci. 2018 Nov 2;9(46):8637-8643. doi: 10.1039/c8sc03712d. eCollection 2018 Dec 14.
Despite the considerable attention given to the applications of magadiite in previous research, the properties of this natural layered silicate have remained mysterious due to the lack of crystal structure information. On the other hand, no one has doubted the intercalation capability the layers. Here we succeed in determining the structure of magadiite using X-ray pair distribution functions and synchrotron powder diffractometry. We discover unexpected zeolitic microchannels the layers. We describe efficient synthesis of 100% pure benzoic acid from toluene by using magadiite as an additive in a TiO photocatalytic system oxidizing toluene. Based on the uncovered structure of magadiite, we clarify the mechanism of this unique photocatalytic system: the microchannels of magadiite not only separate/accommodate the desired partially oxidized product formed on TiO but also prevent the accumulation of the overoxidized products on the TiO surface that deactivates the photocatalytic activity.
尽管在先前的研究中对磁赤铁矿的应用给予了相当多的关注，但由于缺乏晶体结构信息，这种天然层状硅酸盐的性质仍然神秘。另一方面，没有人怀疑层间的插层能力。在这里，我们利用X射线对分布函数和同步辐射粉末衍射法成功地确定了磁赤铁矿的结构。我们在层间发现了意想不到的沸石微通道。我们描述了在TiO光催化氧化甲苯体系中，以磁赤铁矿为添加剂，由甲苯高效合成100%纯苯甲酸的过程。基于所揭示的磁赤铁矿结构，我们阐明了这种独特光催化体系的机理：磁赤铁矿的微通道不仅分离/容纳了在TiO上形成的所需部分氧化产物，而且还防止了过度氧化产物在TiO表面的积累，而这种积累会使光催化活性失活。
