Cascade Electrocatalytic Nitrate Reduction Reaching 100% Nitrate‑N to Ammonia‑N Conversion over Cu2O@CoO Yolk–Shell Nanocubes

Cascade Electrocatalytic Nitrate Reduction Reaching 100% Nitrate‑N to Ammonia‑N Conversion over Cu2O@CoO Yolk–Shell Nanocubes

ACS Nano

10.1021/acsnano.4c03995

https://doi.org/10.1021/acsnano.4c03995

Wenjing Huang, Wenyu Luo, Jiawei Liu, Bei-Er Jia, Carmen Lee, Jinfeng Dong, Lan Yang, Bin Liu, Qingyu Yan

29 July 2024

Huang, W., Luo, W., Liu, J., Jia, B.-E., Lee, C., Dong, J., Yang, L., Liu, B., & Yan, Q. (2024). Cascade Electrocatalytic Nitrate Reduction Reaching 100% Nitrate‑N to Ammonia‑N Conversion over Cu2O@CoO Yolk–Shell Nanocubes. ACS Nano, 18(31), 20258–20267. https://doi.org/10.1021/acsnano.4c03995

The electroreduction of nitrate to ammonia via a selective eight-electron transfer nitrate reduction reaction offers a promising, low energy consumption, pollution-free, green NH3 synthesis strategy alternative to the Haber–Bosch method. However, it remains a great challenge to achieve high NH4+ selectivity and complete conversion from NO3––N to NH4+–N. Herein, we report ingredients adjustable Cu2O@CoO yolk–shell nanocubes featured with tunable inner void spaces and diverse activity centers, favoring the rapid cascade conversion of NO3– into NO2– on Cu2O and NO2– into NH4+ on CoO. Cu2O@CoO yolk–shell nanocubes exhibit super NH4+ Faradaic efficiencies (>99%) over a wide potential window (−0.2 V to −0.9 V versus RHE) with a considerable NH4+ yield rate of 15.27 mg h–1 cm–2 and fantastic cycling stability and long-term chronoamperometric durability. Cu2O@CoO yolk–shell nanocubes exhibited glorious NO3–-N to NH4+–N conversion efficiency in both dilute (500 ppm) and highly concentrated (0.1 and 1 M) NO3– electrolytes, respectively. The nitrate electrolysis membrane electrode assembly system equipped with Cu2O@CoO yolk–shell nanocubes delivers over 99.8% NH4+ Faradaic efficiency at cell voltages of 1.9–2.3 V.

Publisher Copyright

This research / project is supported by the National Research Foundation - Low Carbon Energy Research 2 DHP Energy-efficient Ammonia Cracking by 3D printing and system optimisation
Grant Reference no. : U2305D4001

This research / project is supported by the Ministry of Education - Academic Research Fund Tier 1
Grant Reference no. : RT6/22

This research / project is supported by the A*STAR - Manufacturing, Trade, and Connectivity Programmatic Fund
Grant Reference no. : 23L9b0052

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsnano.4c03995.

https://oar.a-star.edu.sg/communities-collections/articles/23668

1936-0851
1936-086X

Institute of Materials Research and Engineering