title: Water Durable Electride Y₅Si₃: Electronic Structure and Catalytic Activity for Ammonia Synthesis.
abstract: We report an air and water stable electride Y5Si3 and its catalytic activity for direct ammonia synthesis. It crystallizes in the Mn5Si3-type structure and confines 0.79/f.u. anionic electrons in the quasi-one-dimensional holes. These anionic electrons strongly hybridize with yttrium 4d electrons, giving rise to improved chemical stability. The ammonia synthesis rate using Ru(7.8 wt %)-loaded Y5Si3 was as high as 1.9 mmol/g/h under 0.1 MPa and at 400 °C with activation energy of ∼50 kJ/mol. Its strong electron-donating ability to Ru metal of Y5Si3 is considered to enhance nitrogen dissociation and reduce the activation energy of ammonia synthesis reaction. Catalytic activity was not suppressed even after Y5Si3, once dipped into water, was used as the catalyst promoter. These findings provide novel insights into the design of simple catalysts for ammonia synthesis.
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|ACCEL, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Yangfan
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|ACCEL, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Jiang
authors.initials: J
authors.lastname: Li
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Tada
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|ACCEL, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Toda
authors.affiliation: Synchrotron X-ray Station at SPring-8, National Institute for Material Science (NIMS) , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.|Quantum Beam Unit, NIMS , 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Ueda
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|ACCEL, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kitano
authors.affiliation: Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|ACCEL, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Hosono