Acta Phys. -Chim. Sin. ›› 2021, Vol. 37 ›› Issue (3): 1910058.doi: 10.3866/PKU.WHXB201910058

• ARTICLE • Previous Articles     Next Articles

Synthesis of Six Bio-Inspired Nickel-Based Complexes Ligated with Diselenolate Derivatives and Diphosphine Ligands, and Application to Electrocatalytic H2 Evolution

An Xie1, Zhonghua Pan2, Genggeng Luo2,3,*()   

  1. 1 Key Laboratory of Functional Materials and Applications of Fujian Province, School of Materials Science and Engineering, Xiamen University of Technology, Xiamen 361024, Fujian Province, China
    2 College of Materials Science and Engineering, Huaqiao University, Xiamen 361021, Fujian Province, China
    3 State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
  • Received:2019-10-28 Accepted:2019-12-26 Published:2019-12-31
  • Contact: Genggeng Luo E-mail:ggluo@hqu.edu.cn
  • About author:Genggeng Luo, Email: ggluo@hqu.edu.cn; Tel.: +86-592-6162225
  • Supported by:
    the National Natural Science Foundation of China(21641011);the Fujian Key Laboratory of Functional Materials and Applications, China(fma2017107)

Abstract:

In recent years, there has been an intense effort to develop renewable alternatives to fossil fuels for meeting the ever-increasing global energy need. Molecular dihydrogen (H2) is the ideal energy carrier for the 21st century because it has high energy density and its combustion releases only water, and electrocatalysis is a powerful tool for its wide use. Developing new H2-evolving molecular electrocatalysts with cheap and earth-abundant elements is highly desirable. Among all kinds of H2-generating catalysts, [NiFe]-hydrogenases (H2ases) have the active site featuring a redox-active {Ni(cysteinate)4} center bridged through two of its cysteine residues to a redox-inactive {Fe(CN2)(CO)} moiety. As a class of known natural enzymes, [NiFe]-H2ases are promising candidates because they have inexpensive nickel and/or iron atoms at the active sites and can catalyze the reversible reduction of H+ to H2 with high efficiency comparable to the noble-metal platinum. However, the catalytic behaviors of most artificial H2ases-like active sites are usually inhibited by the existence of a small amount of O2, which strongly limit their practical application. As such, it is attractive to develop new analogues of enzyme active sites to address this issue. On the other hand, [NiFeSe]-H2ases, which are obtained by the introduction of Se into [NiFe]-H2ases, have exceptional properties conducive for H2 production, such as high H2 generation performance, marginal inhibition by H2, and high tolerance to O2. The mechanistic understanding of [NiFeSe]-H2ases function guides the design and synthesis of Se-substituted Ni-based molecular catalysts, and selection of suitable bio-inspired catalysts enables applications in catalysis for hydrogen evolution reaction (HER). In this contribution, six bio-inspired neutral nickel-based complexes (2a–2c, 3a–3b, 4) with diselenolate derivatives and diphosphine ligands have been prepared and structurally characterized. These complexes are important in the function of [NiFeSe]-hydrogenase models toward their application as electrocatalysts for the HER. The substituent effects of diselenolate and diphosphine ligands on the catalytic activities of hydrogen production by these nickel(Ⅱ) complexes are studied experimentally. When using a glassy carbon electrode, all the complexes are efficient electrocatalysts for H2 production with different turnover frequencies (TOFs) of 12182 s-1 (2a), 15385 s-1 (2b), 20359 s-1 (2c), 106 s-1 (3a), 794 s-1 (3b), 13580 s-1 (4). The present results indicate that the nickel(Ⅱ) complex 2c ligated by a 4, 5-dimethyl-1, 2-benzenediselenolate and 1, 1'-bis(diphenylphosphino)ferrocene ligand, shows the highest efficiency, which surpasses the activity of a previously dppf-supported nickel(Ⅱ) 1, 2-benzenediselenolate with a TOF of 7838 s-1. We believe that our results will encourage the development of the design of highly efficient Ni-based selenolate molecular catalysts.

Key words: Electrocatalytic hydrogen evolution, Nickel-based complex, Molecular catalysis, Diselenolate derivative, Diphosphine ligand

MSC2000: 

  • O643