{"title":"硝酸转化为氨的无膜电化学合成战略","authors":"Yongguang Bu, Wenjing Yu, Qiang Yang, Wenkai Zhang, Qingyu Sun, Wensu Wu, Peixin Cui, Chao Wang, Guandao Gao","doi":"10.1021/acs.est.4c02445","DOIUrl":null,"url":null,"abstract":"Electroreduction of nitrate (NO<sub>3</sub>RR) to ammonia in membraneless electrolyzers is of great significance for reducing the cost and saving energy consumption. However, severe chemical crossover with side reactions makes it challenging to achieve ideal electrolysis. Herein, we propose a general strategy for efficient membraneless ammonia synthesis by screening NO<sub>3</sub>RR catalysts with inferior oxygen reduction activity and matching the counter electrode (CE) with good oxygen evolution activity while blocking anodic ammonia oxidation. Consequently, screening the available Co–Co system, the membraneless NO<sub>3</sub><sup>–</sup>-to-NH<sub>3</sub> conversion performance was significantly higher than H-type cells using costly proton-exchange membranes. At 200 mA cm<sup>–2</sup>, the full-cell voltage of the membraneless system (∼2.5 V) is 4 V lower than that of the membrane system (∼6.5 V), and the savings are 61.4 kW h (or 56.9%) per 1 kg NH<sub>3</sub> produced. A well-designed pulse process, inducing reversible surface reconstruction that in situ generates and restores the active Co(III) species at the working electrode and forms favorable Co<sub>3</sub>O<sub>4</sub>/CoOOH at the CE, further significantly improves NO<sub>3</sub><sup>–</sup>-to-NH<sub>3</sub> conversion and blocks side reactions. A maximum NH<sub>3</sub> yield rate of 1500.9 μmol cm<sup>–2</sup> h<sup>–1</sup> was achieved at −0.9 V (Faraday efficiency 92.6%). This pulse-coupled membraneless strategy provides new insights into design complex electrochemical synthesis.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8000,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Membraneless Electrochemical Synthesis Strategy toward Nitrate-to-Ammonia Conversion\",\"authors\":\"Yongguang Bu, Wenjing Yu, Qiang Yang, Wenkai Zhang, Qingyu Sun, Wensu Wu, Peixin Cui, Chao Wang, Guandao Gao\",\"doi\":\"10.1021/acs.est.4c02445\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Electroreduction of nitrate (NO<sub>3</sub>RR) to ammonia in membraneless electrolyzers is of great significance for reducing the cost and saving energy consumption. However, severe chemical crossover with side reactions makes it challenging to achieve ideal electrolysis. Herein, we propose a general strategy for efficient membraneless ammonia synthesis by screening NO<sub>3</sub>RR catalysts with inferior oxygen reduction activity and matching the counter electrode (CE) with good oxygen evolution activity while blocking anodic ammonia oxidation. Consequently, screening the available Co–Co system, the membraneless NO<sub>3</sub><sup>–</sup>-to-NH<sub>3</sub> conversion performance was significantly higher than H-type cells using costly proton-exchange membranes. At 200 mA cm<sup>–2</sup>, the full-cell voltage of the membraneless system (∼2.5 V) is 4 V lower than that of the membrane system (∼6.5 V), and the savings are 61.4 kW h (or 56.9%) per 1 kg NH<sub>3</sub> produced. A well-designed pulse process, inducing reversible surface reconstruction that in situ generates and restores the active Co(III) species at the working electrode and forms favorable Co<sub>3</sub>O<sub>4</sub>/CoOOH at the CE, further significantly improves NO<sub>3</sub><sup>–</sup>-to-NH<sub>3</sub> conversion and blocks side reactions. A maximum NH<sub>3</sub> yield rate of 1500.9 μmol cm<sup>–2</sup> h<sup>–1</sup> was achieved at −0.9 V (Faraday efficiency 92.6%). This pulse-coupled membraneless strategy provides new insights into design complex electrochemical synthesis.\",\"PeriodicalId\":36,\"journal\":{\"name\":\"环境科学与技术\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":10.8000,\"publicationDate\":\"2024-07-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"环境科学与技术\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://doi.org/10.1021/acs.est.4c02445\",\"RegionNum\":1,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, ENVIRONMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"环境科学与技术","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1021/acs.est.4c02445","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
摘要
在无膜电解槽中将硝酸盐(NO3RR)电还原成氨对降低成本和节约能耗具有重要意义。然而,严重的化学交叉和副反应使得实现理想的电解过程充满挑战。在此,我们提出了一种高效无膜合成氨的通用策略,即筛选氧还原活性较差的 NO3RR 催化剂,并匹配氧进化活性较好的对电极(CE),同时阻止阳极氨氧化。因此,通过对现有 Co-Co 系统的筛选,无膜 NO3-NH3 转化性能明显高于使用昂贵质子交换膜的 H 型电池。在 200 mA cm-2 的条件下,无膜系统的全电池电压(∼2.5 V)比有膜系统(∼6.5 V)低 4 V,每生产 1 kg NH3 可节省 61.4 kW h(或 56.9%)。精心设计的脉冲过程可诱导可逆的表面重构,在工作电极上原位生成和恢复活性 Co(III)物种,并在 CE 上形成有利的 Co3O4/CoOOH,从而进一步显著提高 NO3 到 NH3 的转化率,并阻断副反应。在-0.9 V电压下,NH3的最大产率达到1500.9 μmol cm-2 h-1(法拉第效率为92.6%)。这种脉冲耦合无膜策略为设计复杂的电化学合成提供了新的思路。
Electroreduction of nitrate (NO3RR) to ammonia in membraneless electrolyzers is of great significance for reducing the cost and saving energy consumption. However, severe chemical crossover with side reactions makes it challenging to achieve ideal electrolysis. Herein, we propose a general strategy for efficient membraneless ammonia synthesis by screening NO3RR catalysts with inferior oxygen reduction activity and matching the counter electrode (CE) with good oxygen evolution activity while blocking anodic ammonia oxidation. Consequently, screening the available Co–Co system, the membraneless NO3–-to-NH3 conversion performance was significantly higher than H-type cells using costly proton-exchange membranes. At 200 mA cm–2, the full-cell voltage of the membraneless system (∼2.5 V) is 4 V lower than that of the membrane system (∼6.5 V), and the savings are 61.4 kW h (or 56.9%) per 1 kg NH3 produced. A well-designed pulse process, inducing reversible surface reconstruction that in situ generates and restores the active Co(III) species at the working electrode and forms favorable Co3O4/CoOOH at the CE, further significantly improves NO3–-to-NH3 conversion and blocks side reactions. A maximum NH3 yield rate of 1500.9 μmol cm–2 h–1 was achieved at −0.9 V (Faraday efficiency 92.6%). This pulse-coupled membraneless strategy provides new insights into design complex electrochemical synthesis.
期刊介绍:
Environmental Science & Technology (ES&T) is a co-sponsored academic and technical magazine by the Hubei Provincial Environmental Protection Bureau and the Hubei Provincial Academy of Environmental Sciences.
Environmental Science & Technology (ES&T) holds the status of Chinese core journals, scientific papers source journals of China, Chinese Science Citation Database source journals, and Chinese Academic Journal Comprehensive Evaluation Database source journals. This publication focuses on the academic field of environmental protection, featuring articles related to environmental protection and technical advancements.