Ebenezer James, Velayudham Parthiban, Schechter Alex
Department of Chemical Sciences, Ariel University, Ariel 40 700, Israel.
Research and Development Centre for Renewable Energy, New Technology Centre, University of West Bohemia, 301 00 Pilsen, Czech Republic.
ACS Appl Mater Interfaces. 2025 Jun 25;17(25):36796-36809. doi: 10.1021/acsami.5c07123. Epub 2025 Jun 12.
In the pursuit of sustainable ammonia synthesis and nitrate remediation, electrochemical nitrate reduction to ammonia (eNORR) emerges as a promising alternative to the carbon-intensive Haber-Bosch process, which emits 1.6-2.0 tons of CO per ton of ammonia. Powered by renewable energy, the eNORR offers reduced emissions and energy consumption but faces challenges in catalytic activity and product selectivity due to its complex mechanism. To address these issues, CeFeO supported CeO composites were synthesized via a microwave polyol method with varying Ce:Fe atomic ratios and comprehensively characterized. Electrochemical analysis revealed that pure CeO achieved a high ammonia yield rate of 4040.5 ± 262.5 μg h cm but with a lower Faradaic efficiency (FE) of 52.8 ± 2.8% at -0.45 V in 0.1 M KOH with 0.1 M NO. Introducing CeFeO into CeO enhanced FE significantly, reaching a maximum of 80.1 ± 3.3% with an ammonia yield rate of 3223.9 ± 168.3 μg h cm. Parasitic hydrogen evolution accounted for only 4.9 ± 0.9% FE, while hydroxylamine and nitrite, key intermediates, contributed 8.3 ± 1.2% and 6.7 ± 0.9%, respectively. Stability was demonstrated over 25 one hour cycles (25 h total) at -0.45 V with electrolyte replacement. The intrinsic perovskite structure of CeFeO, facilitating electron exchange via oxygen vacancies, underpinned the improved performance. H-NO fuel cell studies showed 74.6% thermodynamic efficiency at a current density of 29.7 mA cm at 0.46 V. This study underscores CeFeO/CeO composites' potential for sustainable ammonia production and environmental remediation.
在追求可持续氨合成和硝酸盐修复的过程中，电化学硝酸盐还原制氨（eNORR）成为了碳密集型哈伯-博施法的一种有前景的替代方法，哈伯-博施法每生产一吨氨会排放1.6 - 2.0吨二氧化碳。由可再生能源驱动的eNORR减少了排放和能源消耗，但由于其复杂的机制，在催化活性和产物选择性方面面临挑战。为了解决这些问题，通过微波多元醇法合成了具有不同Ce:Fe原子比的CeFeO负载CeO复合材料，并进行了全面表征。电化学分析表明，在含有0.1 M NO的0.1 M KOH溶液中，-0.45 V时，纯CeO实现了4040.5±262.5 μg h cm的高氨产率，但法拉第效率（FE）较低，为52.8±2.8%。将CeFeO引入CeO中显著提高了FE，在氨产率为3223.9±168.3 μg h cm时，FE最高达到80.1±3.3%。寄生析氢仅占FE的4.9±0.9%，而关键中间体羟胺和亚硝酸盐分别贡献了8.3±1.2%和6.7±0.9%。在-0.45 V下进行25个一小时循环（总计25小时）并更换电解液，证明了其稳定性。CeFeO的本征钙钛矿结构通过氧空位促进电子交换，这是性能提高的基础。H-NO燃料电池研究表明，在0.46 V、电流密度为29.7 mA cm时，热力学效率为74.6%。本研究强调了CeFeO/CeO复合材料在可持续氨生产和环境修复方面的潜力。
