Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (3): 401-406.DOI: 10.1016/S1872-2067(17)62945-0

• Communications • Previous Articles     Next Articles

Structural change of molybdenum sulfide facilitates the electrocatalytic hydrogen evolution reaction at neutral pH as revealed by in situ Raman spectroscopy

Yamei Lia, Ryuhei Nakamuraa,b   

  1. a Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science(CSRS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan;
    b Earth-Life Science Institute(ELSI), Tokyo Institute of Technology, 2-12-1-I7 E Ookayama, Meguro-ku, Tokyo 152-8550, Japan
  • Received:2017-09-27 Revised:2017-10-26 Online:2018-03-18 Published:2018-03-10
  • Contact: 10.1016/S1872-2067(17)62945-0
  • Supported by:

    This work was supported by a JSPS Grant-in-Aid for Scientific Research (26288092).


Molybdenum sulfides are promising electrocatalysts for the hydrogen evolution reaction (HER). S-and Mo-related species have been proposed as the active site for forming adsorbed hydrogen to initiate the HER; however, the nature of the interaction between Mo centers and S ligands is unclear. Further, the development of cost-effective water-splitting systems using neutral water as a proton source for H2 evolution is highly desirable, whereas the mechanism of the HER at neutral pH is rarely discussed. Here, the structural change in the Mo-Mo and S-S species in a synthesized molybdenum sulfide was monitored at neutral pH using in situ electrochemical Raman spectroscopy. Analysis of the potential dependent Raman spectra revealed that the band assigned to a terminal S-S species emerged along with synchronized changes in the frequency of the Mo-Mo, Mo33S, and Mo-S vibrational bands. This indicates that Mo-Mo bonds and terminal S-S ligands play synergistic roles in facilitating hydrogen evolution, likely via the internal reorganization of trinuclear Mo3-thio species. The nature and role of metal-ligand interactions in the HER revealed in this study demonstrated a mechanism that is distinct from those reported previously in which the S or Mo sites function independently.

Key words: Hydrogen evolution reaction, Molybdenum sulfide, Electrocatalyst, In-situ Raman spectroscopy, Artificial photosynthesis, Clean energy