Composite Cathodes with Oxide and Nitride Phases for High-Temperature Electrocatalytic Ammonia Production from Nitrogen and Water
Composite Cathodes with Oxide and Nitride Phases for High-Temperature Electrocatalytic Ammonia Production from Nitrogen and Water
复制标题
用于氮和水高温电催化制氨的氧化物和氮化物相复合阴极
DOI：
10.1149/2754-2734/ac6618
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Ozkan, Umit S.
中科院分区：
文献类型：
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作者：
Gunduz, Seval;Deka, Dhruba J.;Ferree, Matt;Kim, Jaesung;Millet, Jean-Marc M.;Co, Anne C.;Ozkan, Umit S.
氨（nh3）生产的传统途径是Haber-Bosch （HB）工艺，该工艺通过高温高压的热催化反应转化氮和氢。在较小的规模下，HB工艺效率不高，也不经济。近年来在电催化制氨方面取得了重大进展。虽然在水介质中低温直接电化学合成nh3已有报道，但关于高温电催化的研究却少之又少。高温路线有可能提高催化活性，降低动力学过电位，提高nh3生成的法拉第效率。本研究的重点是在固体氧化物电解池（SOEC）型反应器中，以氮气和h2o为原料，在大气压下高温（600℃）电化学合成氨。工作电极的催化材料选择是电化学过程中最重要的挑战之一。本文研究了一种由钙钛矿氧化物和氮化铁氧化物相组成的复合阴极。采用XRD， XPS， Mössbauer光谱，TPD/TPRxn和4探针电导率技术对两相进行了全面表征。在钙钛矿氧化物相和复合阴极上进行了电催化活性实验，研究了复合电极对电池活性的影响。
The conventional route for ammonia (NH 3) production is the Haber-Bosch (HB) process, which converts nitrogen and hydrogen through a thermo-catalytic reaction at high temperatures and pressures. The HB process is not efficient or economical at smaller scales. Recent years have seen significant effort in producing ammonia electrocatalytically. While direct electrochemical synthesis of NH 3 has been reported at low temperatures in aqueous media, studies on high-temperature electrocatalysis are much fewer. High-temperature routes have the potential to increase catalytic activity, lower the kinetic overpotential, and improve Faradaic efficiency for NH 3 formation. The focus of the present study is high-temperature (600 C) electrochemical synthesis of ammonia from N 2 and H 2 O at atmospheric pressure in solid oxide electrolysis cell (SOEC)-type reactors. The catalytic material selection for the working electrode is one of the most important challenges in electrochemical processes. In this work, a composite cathode composed of a perovskite oxide and an iron oxynitride phase was investigated. Both phases were characterized thoroughly using XRD, XPS, Mössbauer spectroscopy, TPD/TPRxn, and 4-probe electrical conductivity techniques. The electrocatalytic activity experiments were performed on the perovskite oxide phase and the composite cathode to study the effect of using a composite electrode on the activity of the cell.