(SEMINAR) Lifeng Liu, PhD Songshan Lake Materials Laboratory (SLAB), Dongguan, China

Seawater electrolysis is a promising approach to hydrogen production but faces formidable technical challenges in practical applications. In particular, the interfering chlorine evolution reaction (CER) not only competes with the oxygen evolution reaction (OER) at the anode compromising the Faradaic efficiency, but the chlorine and/or hypochlorite generated under high voltages and large current densities may corrode materials and components of electrolyzers, shortening their lifetime. Recently, asymmetric seawater electrolysis has drawn considerable attention because it can help address the challenges mentioned above.[1] Asymmetric seawater electrolysis takes advantage of the small molecule oxidation reaction (SMOR) to replace the energy-demanding OER. The coupling of SMOR with the hydrogen evolution reaction (HER) not only enables efficient production of hydrogen, but also allows for co-production of value-added chemicals/fuels or treatment of chemical/environmental wastes, substantially enhancing the economic viability of seawater electrolysis. Meanwhile, the SMOR typically occurs at a remarkably lower anodic potential than the OER, and therefore can significantly reduce the energy consumption of seawater electrolysis. Besides, the electrolyzer is able to operate at high current densities without the interference of CER. In this presentation, the speaker will give an overview about the research carried out in his team on symmetric seawater electrolysis, based on the methanol oxidation reaction (MOR), [2] the urea oxidation reaction (UOR),[3] iodide oxidation reaction (IOR),[4] hydrazine oxidation reaction (HzOR),[5,6] and sulfion oxidation reaction (SOR).[7] Besides the performance in the aqueous model system, the speaker will also present some results obtained in prototype asymmetric electrolyzers to validate the viability of asymmetric seawater electrolysis for large-scale applications.

 

References:
[1] Yu, Z. P.; Liu, L. Adv. Mater. 2023, 2308647.
[2] Xu, K. Y.; Liang, L. C.; Li, T.; Bao, M. J.; Yu, Z. P.; Wang, J. W.; Thalluri, S. M.; Lin,
F.; Liu, Q. B.; Cui, Z. M.; Song, S. Q.; Liu, L. Adv. Mater. 2024, 2403792.
[3] Yu, Z.; Li, Y.; Martin-Diaconescu, V.; Simonelli, L.; Esquius, J. R.; Amorim, I.;
Araujo, A.; Meng, L.; Faria, J. L.; Liu, L. Adv. Funct. Mater. 2022, 32: 2206138.
[4] Tan, H.; Yu, Z.; LaGrow, A. P.; Ma, S.; Wang, J.; Li, H.; Xiong, D.; Liu, L. J. Mater.
Chem. A 2023, 11: 26152.
[5] Yu, Z.; Xu, J.; Meng, L.; Liu, L. J. Mater. Chem. A 2021, 9: 22248.
[6] Yu, Z.; D’Olimpio, G.; Huang, H.; Kuo, C. N.; Lue, C. S.; Nicotra, G.; Lin, F.;
Boukhvalov, D. W.; Politano, A.; Liu, L. Adv. Funct. Mater. 2024, 2403099

[7] Tan, H.; Yu, Z.; Lin, F.; Ma, S.; Huang, H.; Li, H.; Zhang, L.; Xiong, D.; Liu, L. Adv.
Mater. In revision