{"title":"Boosting electroreduction of nitrate to ammonia by modulating the crystalline phase of Fe2O3","authors":"Qiang Ru, Peiyao Bai, Xiao Kong, Lang Xu","doi":"10.1016/j.ces.2024.120378","DOIUrl":null,"url":null,"abstract":"<div><p>Electrocatalytic nitrate reduction reaction (NO<sub>3</sub>RR) provides an alternative to the conventional Haber-Bosch process for ammonia synthesis and is an effective method for removal of nitrate ions from polluted waters, which is highly significant from both energy and environmental perspectives. However, NO<sub>3</sub>RR involves the complex eight-electron process alongside various nitrogen-containing intermediates and is also in competition with hydrogen evolution reaction, thus demanding highly active and selective electrocatalysts. In this work we prepare a Ni-doped Fe<sub>2</sub>O<sub>3</sub> electrocatalyst via a solvent-free route. It is found that the addition of Ni induces the crystalline-phase transformation of Fe<sub>2</sub>O<sub>3</sub> from γ-Fe<sub>2</sub>O<sub>3</sub> to α-Fe<sub>2</sub>O<sub>3</sub>. The density functional theory (DFT) results reveal that compared to γ-Fe<sub>2</sub>O<sub>3</sub>, α-Fe<sub>2</sub>O<sub>3</sub> gives rise to a lower potential-determining step (PDS) energy barrier, leading to the more thermodynamically favourable reaction. By modulating the crystalline phase, the optimal catalyst achieves high ammonia yield rates of > 5000 μg h<sup>−1</sup> cm<sup>−2</sup> and faradaic efficiencies of > 90 %, showcasing its high electrocatalytic activity and selectivity. From this perspective, this paper provides new insights and strategies for the green nitrate-to-ammonia conversion.</p></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S000925092400678X","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Electrocatalytic nitrate reduction reaction (NO3RR) provides an alternative to the conventional Haber-Bosch process for ammonia synthesis and is an effective method for removal of nitrate ions from polluted waters, which is highly significant from both energy and environmental perspectives. However, NO3RR involves the complex eight-electron process alongside various nitrogen-containing intermediates and is also in competition with hydrogen evolution reaction, thus demanding highly active and selective electrocatalysts. In this work we prepare a Ni-doped Fe2O3 electrocatalyst via a solvent-free route. It is found that the addition of Ni induces the crystalline-phase transformation of Fe2O3 from γ-Fe2O3 to α-Fe2O3. The density functional theory (DFT) results reveal that compared to γ-Fe2O3, α-Fe2O3 gives rise to a lower potential-determining step (PDS) energy barrier, leading to the more thermodynamically favourable reaction. By modulating the crystalline phase, the optimal catalyst achieves high ammonia yield rates of > 5000 μg h−1 cm−2 and faradaic efficiencies of > 90 %, showcasing its high electrocatalytic activity and selectivity. From this perspective, this paper provides new insights and strategies for the green nitrate-to-ammonia conversion.
期刊介绍:
Chemical engineering enables the transformation of natural resources and energy into useful products for society. It draws on and applies natural sciences, mathematics and economics, and has developed fundamental engineering science that underpins the discipline.
Chemical Engineering Science (CES) has been publishing papers on the fundamentals of chemical engineering since 1951. CES is the platform where the most significant advances in the discipline have ever since been published. Chemical Engineering Science has accompanied and sustained chemical engineering through its development into the vibrant and broad scientific discipline it is today.