Electride support boosts nitrogen dissociation over ruthenium catalyst and shifts the bottleneck in ammonia synthesis.
Electride support boosts nitrogen dissociation over ruthenium catalyst and shifts the bottleneck in ammonia synthesis.
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DOI：
10.1038/ncomms7731
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发表时间：
2015-03-30
影响因子：
16.6
通讯作者：
Hosono, Hideo
中科院分区：
文献类型：
--
作者：
Kitano, Masaaki;Kanbara, Shinji;Inoue, Yasunori;Kuganathan, Navaratnarajah;Sushko, Peter V.;Yokoyama, Toshiharu;Hara, Michikazu;Hosono, Hideo
积极地寻求在环境压力下有效合成氨的新方法，以降低氨生产的成本并允许紧凑的生产设施。公认的关键是开发一种高性能催化剂，其显著增强氮-氮三键的解离，这通常被认为是速率决定步骤。本文研究了最近发现的一种高效氨合成催化剂--负载钌的12 CaO·7Al 2 O3双金属氧化物（Ru/C12 A7：e-）的氮、氢同位素交换和氢吸附/脱附反应动力学，发现Ru/C12 A7：e-上氨合成的速率控制步骤不是氮-氮三键的解离，而是随后的N-Hn物种的形成。氨合成的机制，涉及可逆的存储和释放的氢原子的Ru/C12 A7：e−表面上的基础上观察到的吸/脱附动力学提出。 开发促进氮-氮三键解离的催化剂将降低氨生产的成本。在这里，作者研究了在钌负载的氨氧化物催化剂上的氨合成，并表明，速率决定步骤转移到氮-氢键的形成。
Novel approaches to efficient ammonia synthesis at an ambient pressure are actively sought out so as to reduce the cost of ammonia production and to allow for compact production facilities. It is accepted that the key is the development of a high-performance catalyst that significantly enhances dissociation of the nitrogen–nitrogen triple bond, which is generally considered a rate-determining step. Here we examine kinetics of nitrogen and hydrogen isotope exchange and hydrogen adsorption/desorption reactions for a recently discovered efficient catalyst for ammonia synthesis—ruthenium-loaded 12CaO·7Al2O3 electride (Ru/C12A7:e−)—and find that the rate controlling step of ammonia synthesis over Ru/C12A7:e− is not dissociation of the nitrogen–nitrogen triple bond but the subsequent formation of N–Hn species. A mechanism of ammonia synthesis involving reversible storage and release of hydrogen atoms on the Ru/C12A7:e− surface is proposed on the basis of observed hydrogen absorption/desorption kinetics. Development of catalysts that enhance dissociation of the nitrogen–nitrogen triple bond will reduce costs of ammonia production. Here, the authors study ammonia synthesis over a ruthenium loaded electride catalyst and show that the rate-determining step is shifted to nitrogen–hydrogen bond formation.
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影响因子：
21.8
作者：
Kitano, Masaaki;Inoue, Yasunori;Hosono, Hideo
通讯作者：
Hosono, Hideo
影响因子：
64.8
作者：
LACERDA, M;IRVINE, JTS;WEST, AR
通讯作者：
WEST, AR
影响因子：
15
作者：
Hayashi, K;Hirano, M;Hosono, H
通讯作者：
Hosono, H
影响因子：
4
作者：
Hayashi, Katsuro;Hirano, Masahiro;Hosono, Hideo
通讯作者：
Hosono, Hideo
影响因子：
7.3
作者：
AIKA, K;OZAKI, A;HORI, H
通讯作者：
HORI, H