Boosting hydrogen adsorption via manipulating interfacial electronic structure of NiPx for enhanced alkaline seawater electrolysis

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.499, p.155925, Article 155925
• Main Authors: Chen, Xu, Duan, Yunrui, Dou, Huanglin, Zhang, Wensheng, Wang, Xiaomin
• Format: Article
• Language: English
• Subjects: Electron redistribution; Heteroatom; Heterostructure; Hydrogen evolution reaction; Metal phosphide
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155925

[Display omitted] The development of transition metal phosphides (TMPs) electrocatalysts with appropriate binding strength towards intermediates and resistant to chlorine in alkaline seawater electrocatalysis remains a formidable challenge. Herein, an approach for manipulating electron redistribution in Ni2P/Ni5P4 treated by Co cationic doping engineering (denoted as Act-Co-NiPx) is proposed, exhibiting excellent catalytic activities and stability toward HER in alkaline seawater solution. First-principles calculations demonstrate that the Co doping can effectively adjust the electron redistribution of Ni2P/Ni5P4, resulting in a reduction in the hydrogen adsorption free energy for HER and an acceleration in the interfacial charge transfer. Furthermore, the enhanced Cl- adsorption energy avoids the toxicity of Cl- to the active sites in alkaline seawater splitting. Consequently, the resulting Act-Co-NiPx catalyst demonstrates remarkable HER performance with low overpotentials of 77 and 97 mV at a current density of 10 mA cm−2 in both 1.0 M KOH and 1.0 M KOH+Seasalt electrolytes. Furthermore, the seasalt electrolyzer assembled from Act-Co-NiPx achieves the low cell voltage of 1.63 V at 10 mA cm−2. This work demonstrates a feasible method for designing cost-effective and stable catalysts with excellent selectivity via regulating the electronic structure of TMPs for seawater electrolysis.