Volume 63, Issue 15 e202400428
Research Article

Matched Kinetics Process Over Fe2O3-Co/NiO Heterostructure Enables Highly Efficient Nitrate Electroreduction to Ammonia

Qiang Yang

Qiang Yang

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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Yongguang Bu

Yongguang Bu

State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, 210023 Nanjing, China

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Shuailei Pu

Shuailei Pu

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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Longgang Chu

Longgang Chu

State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, 210023 Nanjing, China

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Weifeng Huang

Weifeng Huang

College of Chemistry and Chemical Engineering, Qiannan Normal University for Nationalities, 558000 Duyun, China

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Prof. Xiangdong Zhu

Prof. Xiangdong Zhu

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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Cun Liu

Cun Liu

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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Prof. Guodong Fang

Prof. Guodong Fang

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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Prof. Peixin Cui

Corresponding Author

Prof. Peixin Cui

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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Prof. Dongmei Zhou

Prof. Dongmei Zhou

State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, 210023 Nanjing, China

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Prof. Yujun Wang

Corresponding Author

Prof. Yujun Wang

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008 China

University of Chinese Academy of Sciences, Beijing, 100049 China

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First published: 30 January 2024
Citations: 17

Graphical Abstract

We developed a strategy for Ni2+ substitution of Co2+ to develop an oxide heterostructure on (Co0.83Ni0.16)2Fe layered double oxides (LDOs) for highly efficient electroreduction nitrate reduction reaction (NO3RR) to ammonia (NH3), where Ni plays a dual role in NO3RR by i) modifying the electronic behavior of Co, and ii) serving as complementary sites for active hydrogen (*H) supply. Therefore, the adsorption capacity of *NO2 and its subsequent hydrogenation on the Co sites became more thermodynamically feasible.

Abstract

Tandem nitrate electroreduction reaction (NO3RR) is a promising method for green ammonia (NH3) synthesis. However, the mismatched kinetics processes between NO3-to-NO2 and NO2-to-NH3 results in poor selectivity for NH3 and excess NO2 evolution in electrolyte solution. Herein, a Ni2+ substitution strategy for developing oxide heterostructure in Co/Fe layered double oxides (LDOs) was designed and employed as tandem electrocataltysts for NO3RR. (Co0.83Ni0.16)2Fe exhibited a high NH3 yield rate of 50.4 mg ⋅ cm−2 ⋅ h−1 with a Faradaic efficiency of 97.8 % at −0.42 V vs. reversible hydrogen electrode (RHE) in a pulsed electrolysis test. By combining with in situ/operando characterization technologies and theoretical calculations, we observed the strong selectivity of NH3 evolution over (Co0.83Ni0.16)2Fe, with Ni playing a dual role in NO3RR by i) modifying the electronic behavior of Co, and ii) serving as complementary site for active hydrogen (*H) supply. Therefore, the adsorption capacity of *NO2 and its subsequent hydrogenation on the Co sites became more thermodynamically feasible. This study shows that Ni substitution promotes the kinetics of the NO3RR and provides insights into the design of tandem electrocatalysts for NH3 evolution.

Conflict of interests

The authors declare no conflict of interest.

Data Availability Statement

Data supporting the findings of this study are available upon request from the corresponding authors. The data are not publicly available because of privacy and ethical restrictions.

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