Advances in catalysts and reaction systems for electro/photocatalytic ammonia production

Abstract

Ammonia is a vital component in the fertilizer and chemical industries, as well as serving as a significant carrier of renewable hydrogen energy. Compared with the industry’s principal technique, the Haber-Bosch method, for ammonia synthesis, electro/photocatalytic ammonia synthesis is increasingly recognized as a viable and eco-friendly alternative. This method enables distributed small-scale deployment and can be powered by sustainable renewable energy sources. However, the efficiency of electro/photocatalytic nitrogen reduction reaction is hindered by the challenges in activating the N≡N bond and nitrogen’s low solubility, thereby limiting its large-scale industrial applications. In this review, recent advancements in electro/photocatalytic nitrogen reduction are summarized, encompassing the complex reaction mechanisms, as well as the effective strategies for developing electro/photocatalytic catalysts and advanced reaction systems. Furthermore, the energy efficiency and economic analysis of electro/photocatalytic nitrogen fixation are deeply discussed. Finally, some unsolved challenges and potential opportunities are discussed for the future development of electro/photocatalytic ammonia synthesis.

Key words： ammonia synthesis; electro/photocatalysis; nitrogen fixation; reaction system; economic and efficiency analysis

Competing interests

The authors declare that they have no competing interests.

Acknowledgements

This work was supported by the National Key R&D Project of China (Grant No. 2020YFA0710000), the National Natural Science Foundation of China (Grant Nos. 22309152, 22311530118, and 22109132), the Provincial Key Research and Development Project of Sichuan (Grant No. 24SYSX0175), the International Science and Technology Cooperation Project of Chengdu (Grant No. 2021-GH02-00052-HZ), the Technology Innovation R&D Project of Chengdu (Grant No. 2022-YF05-00978-SN), and the Scientific Research Starting Project of SWPU (Grant No. 2021QHZ028), Production-Education Integration Demonstration Project of Sichuan Province “Photovoltaic Industry Production-Education Integration Comprehensive Demonstration Base of Sichuan Province (Sichuan Financial Education [2022] No. 106)”, Research and Innovation Fund for Graduate Students of Southwest Petroleum University (No. 2022KYCX115).

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