caa a22 4500 463223276 CHVBK 20180405153219.0 cr unu---uuuuu 170326e20070301xx s 000 0 eng 10.1007/s10853-006-1316-9 doi (NATIONALLICENCE)springer-10.1007/s10853-006-1316-9 Active anion manipulation for emergence of active functions in the nanoporous crystal 12CaO·7Al2O3: a case study of abundant element strategy [Elektronische Daten] [Hideo Hosono, Katsuro Hayashi, Masahiro Hirano] This article reviews our approach to render 12CaO·7Al2O3 (C12A7) electronically active using a new concept of ‘active anion manipulation', where nanostructures embedded within the C12A7 crystal lattice are intentionally utilized to generate chemically unstable (‘water-free active') anions. Anionic active oxygen radicals, O− and O 2 − , are formed efficiently in C12A7 cages under high oxygen activity conditions. The configuration and dynamics of O 2 − in cages are revealed by a combination of continuous-wave and pulsed electron paramagnetic resonance (EPR). It is demonstrated that metal-loaded C12A7 is a promising oxidation catalyst for syngas (CO+H2) formation from methane. Furthermore, the O− ion, the strongest oxidant among active oxygen species, can be extracted from the cage into an external vacuum by applying an electric field with thermal assistance, generating a high-density O− beam in the order of μAcm−2. In contrast, heat treatment of C12A7 in a hydrogen atmosphere forms H− ions in the cages. The resultant C12A7:H− exhibits a persistent insulator-conductor conversion upon ultraviolet-light or electron-beam irradiation. The irradiation-induced conversion mechanism is examined by first-principle theoretical calculations. Furthermore, the presence of a severely reducing environment causes the complete substitution of electrons for anions in the cages. The resulting C12A7:e−, which exhibits excellent stability and an electrical conductivity greater than 100Scm−1, is regarded as an ‘electride', an ionic compound in which electrons serve as anions. The C12A7 electride exhibits a high potential for applications involving cold cathode and thermal field electron emissions due to its small work function. Electride fabrication methods suitable for large-scale production via melt processing are described. It is also demonstrated that proton or inert gas ion implantations into C12A7 thin films at elevated temperatures are effective for both H− and electron doping. Springer Science+Business Media, LLC, 2007 Hosono Hideo Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, S2-13, 226-8503, Yokohama, Japan aut Hayashi Katsuro Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, S2-13, 226-8503, Yokohama, Japan aut Hirano Masahiro Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, S2-13, 226-8503, Yokohama, Japan aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/6(2007-03-01), 1872-1883 0022-2461 42:6<1872 2007 42 10853 https://doi.org/10.1007/s10853-006-1316-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-1316-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hosono Hideo Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, S2-13, 226-8503, Yokohama, Japan aut NATIONALLICENCE 700 1- Hayashi Katsuro Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, S2-13, 226-8503, Yokohama, Japan aut NATIONALLICENCE 700 1- Hirano Masahiro Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, S2-13, 226-8503, Yokohama, Japan aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/6(2007-03-01), 1872-1883 0022-2461 42:6<1872 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer