Manipulating electronic structure of nickel phosphide via asymmetric coordination interaction for anion-exchange membrane based seawater electrolysis

• Published in: Applied catalysis. B, Environmental Environmental, 2024-08, Vol.351, p.123995, Article 123995
• Main Authors: Xia, Yanan, Guo, Lili, Zhu, Jiawei, Tang, Junheng, Li, Zhipeng, Liu, Xiaobin, Chi, Jingqi, Wang, Lei
• Format: Article
• Language: English
• Subjects: Anion·exchange membrane water electrolyzer; Asymmetric construction; Bifunctional electrocatalyst; Seawater splitting
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2024.123995

Alkaline seawater electrolysis faces serious problems such as low catalytic activity of bifunctional catalysts and vulnerability to Cl- corrosion. Hence, Ru-doped nickel phosphide asymmetric structure (Ru-Ni2P/Ni5P4) has been synthesized as highly efficient and corrosion resistant electrocatalysts for alkaline seawater electrolysis at high current density. In-situ characterization technique and DFT calculations reveal that compared with the monophase nickel phosphide, the construction of NixP asymmetric structure manipulate the electronic structure and d-band center, promoting the adsorption of intermediates, as well as accelerate phase transition of the OER process. Moreover, the weak adsorption energy of Cl- on the surface of the Ru-Ni2P/Ni5P4 catalyst avoids the corrosion of Cl- in seawater. Consequently, Ru-Ni2P/Ni5P4 achieve 1000 mA cm−2 with overpotentials of only 128 and 450 mV for HER and OER, respectively. After assembling the Anion-exchange-membrane water electrolyzer (AEMWE), Ru-Ni2P/Ni5P4 shows high average efficiency and economic value at different current densities, and demonstrates its corrosion resistance to Cl- and potential for industrial applications. [Display omitted] •Asymmetric NixP regulates the d-band center, optimizing the adsorption of H*.•The asymmetric structure accelerates reconstruction of OER, improving the catalytic activity in OER.•The co-doping of Ru/P inhibits the corrosion of Cl- and enhances the selectivity of OH-.•In seawater AEM electrolyzer, Ru-Ni2P/Ni5P4 exhibits excellent stability and economic value.