Xian Meng , Jian Liu , Zujian Tang , Bingxu Xi , Pu Yan , Xingran Wang , Kecheng Cao , Bo Yang , Xiaofei Guan
{"title":"由锂锌合金和锂盐-氯化钾组成的熔融多相催化系统,用于在常压下固氮和合成氨","authors":"Xian Meng , Jian Liu , Zujian Tang , Bingxu Xi , Pu Yan , Xingran Wang , Kecheng Cao , Bo Yang , Xiaofei Guan","doi":"10.1039/d4cy00202d","DOIUrl":null,"url":null,"abstract":"<div><p>Ammonia (NH<sub>3</sub>) is one of the most important synthetic inorganic commodities. The current industrial NH<sub>3</sub> production is dominated by the Haber–Bosch process with high energy cost and CO<sub>2</sub> emission as well as the need for large-scale centralized operation. Liquid metals and molten salts have recently emerged as promising catalytic materials for NH<sub>3</sub> synthesis. Herein, we present a molten system comprising Li–Zn alloy and eutectic LiCl–KCl salt for effective NH<sub>3</sub> synthesis at 400 °C and 1 bar. The 70 mol% Li–Zn liquid alloy activates N<sub>2</sub> dissociation more easily than the pure liquid Zn and the 60 mol% Li–Sn liquid alloy. Effective N<sub>2</sub> fixation by the liquid Li–Zn alloy is followed by the hydrogenation of Li<sub>3</sub>N dissolved in the molten salt above. For the first time, this work reports a volcano-type relationship between the Li<sub>3</sub>N concentration in the molten salt and the NH<sub>3</sub> synthesis rate when feeding H<sub>2</sub> to the molten salt. <em>Ab initio</em> molecular dynamics simulations suggest that, within this system, both N<sub>2</sub> cleavage and Li<sub>3</sub>N hydrogenation are quite reactive. Through combined experiments and simulations, this work unravels the molecular mechanisms of nitrogen fixation and ammonia synthesis in the liquid alloy–salt catalytic system, and also demonstrates effective strategies for improving the ammonia synthesis rate. Such a hybrid molten catalytic system offers a promising solution for distributed NH<sub>3</sub> production with low energy cost and CO<sub>2</sub> emission.</p></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":null,"pages":null},"PeriodicalIF":4.4000,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Molten multi-phase catalytic system comprising Li–Zn alloy and LiCl–KCl salt for nitrogen fixation and ammonia synthesis at ambient pressure†\",\"authors\":\"Xian Meng , Jian Liu , Zujian Tang , Bingxu Xi , Pu Yan , Xingran Wang , Kecheng Cao , Bo Yang , Xiaofei Guan\",\"doi\":\"10.1039/d4cy00202d\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Ammonia (NH<sub>3</sub>) is one of the most important synthetic inorganic commodities. The current industrial NH<sub>3</sub> production is dominated by the Haber–Bosch process with high energy cost and CO<sub>2</sub> emission as well as the need for large-scale centralized operation. Liquid metals and molten salts have recently emerged as promising catalytic materials for NH<sub>3</sub> synthesis. Herein, we present a molten system comprising Li–Zn alloy and eutectic LiCl–KCl salt for effective NH<sub>3</sub> synthesis at 400 °C and 1 bar. The 70 mol% Li–Zn liquid alloy activates N<sub>2</sub> dissociation more easily than the pure liquid Zn and the 60 mol% Li–Sn liquid alloy. Effective N<sub>2</sub> fixation by the liquid Li–Zn alloy is followed by the hydrogenation of Li<sub>3</sub>N dissolved in the molten salt above. For the first time, this work reports a volcano-type relationship between the Li<sub>3</sub>N concentration in the molten salt and the NH<sub>3</sub> synthesis rate when feeding H<sub>2</sub> to the molten salt. <em>Ab initio</em> molecular dynamics simulations suggest that, within this system, both N<sub>2</sub> cleavage and Li<sub>3</sub>N hydrogenation are quite reactive. Through combined experiments and simulations, this work unravels the molecular mechanisms of nitrogen fixation and ammonia synthesis in the liquid alloy–salt catalytic system, and also demonstrates effective strategies for improving the ammonia synthesis rate. Such a hybrid molten catalytic system offers a promising solution for distributed NH<sub>3</sub> production with low energy cost and CO<sub>2</sub> emission.</p></div>\",\"PeriodicalId\":66,\"journal\":{\"name\":\"Catalysis Science & Technology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.4000,\"publicationDate\":\"2024-06-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Catalysis Science & Technology\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/org/science/article/pii/S2044475324002971\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis Science & Technology","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/org/science/article/pii/S2044475324002971","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Molten multi-phase catalytic system comprising Li–Zn alloy and LiCl–KCl salt for nitrogen fixation and ammonia synthesis at ambient pressure†
Ammonia (NH3) is one of the most important synthetic inorganic commodities. The current industrial NH3 production is dominated by the Haber–Bosch process with high energy cost and CO2 emission as well as the need for large-scale centralized operation. Liquid metals and molten salts have recently emerged as promising catalytic materials for NH3 synthesis. Herein, we present a molten system comprising Li–Zn alloy and eutectic LiCl–KCl salt for effective NH3 synthesis at 400 °C and 1 bar. The 70 mol% Li–Zn liquid alloy activates N2 dissociation more easily than the pure liquid Zn and the 60 mol% Li–Sn liquid alloy. Effective N2 fixation by the liquid Li–Zn alloy is followed by the hydrogenation of Li3N dissolved in the molten salt above. For the first time, this work reports a volcano-type relationship between the Li3N concentration in the molten salt and the NH3 synthesis rate when feeding H2 to the molten salt. Ab initio molecular dynamics simulations suggest that, within this system, both N2 cleavage and Li3N hydrogenation are quite reactive. Through combined experiments and simulations, this work unravels the molecular mechanisms of nitrogen fixation and ammonia synthesis in the liquid alloy–salt catalytic system, and also demonstrates effective strategies for improving the ammonia synthesis rate. Such a hybrid molten catalytic system offers a promising solution for distributed NH3 production with low energy cost and CO2 emission.
期刊介绍:
A multidisciplinary journal focusing on cutting edge research across all fundamental science and technological aspects of catalysis.
Editor-in-chief: Bert Weckhuysen
Impact factor: 5.0
Time to first decision (peer reviewed only): 31 days