Operando characterization of an amorphous molybdenum sulfide nanoparticle catalyst during the hydrogen evolution reaction

Hernan G.Sanchez Casalongue, Jesse D. Benck, Charlie Tsai, Rasmus K.B. Karlsson, Sarp Kaya, May Ling Ng, Lars G.M. Pettersson, Frank Abild-Pedersen, J. K. Nørskov, Hirohito Ogasawara, Thomas F. Jaramillo, Anders Nilsson*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Molybdenum sulfide structures, particularly amorphous MoS3 nanoparticles, are promising materials in the search for cost-effective and scalable water-splitting catalysts. Ex situ observations show that the nanoparticles exhibit a composition change from MoS3 to defective MoS2 when subjected to hydrogen evolution reaction (HER) conditions, raising questions regarding the active surface sites taking part in the reaction. We tracked the in situ transformation of amorphous MoS3 nanoparticles under HER conditions through ambient pressure X-ray photoelectron spectroscopy and performed density functional theory studies of model MoSx systems. We demonstrate that, under operating conditions, surface sites are converted from MoS3 to MoS2 in a gradual manner and that the electrolytic current densities are proportional to the extent of the transformation. We also posit that it is the MoS2 edge-like sites that are active during HER, with the high activity of the catalyst being attributed to the increase in surface MoS2 edge-like sites after the reduction of MoS3 sites.

Original languageEnglish
JournalJournal of Physical Chemistry C
Volume118
Issue number50
Pages (from-to)29252-29259
Number of pages8
ISSN1932-7447
DOIs
Publication statusPublished - 2014
Externally publishedYes

Cite this

Casalongue, H. G. S., Benck, J. D., Tsai, C., Karlsson, R. K. B., Kaya, S., Ng, M. L., Pettersson, L. G. M., Abild-Pedersen, F., Nørskov, J. K., Ogasawara, H., Jaramillo, T. F., & Nilsson, A. (2014). Operando characterization of an amorphous molybdenum sulfide nanoparticle catalyst during the hydrogen evolution reaction. Journal of Physical Chemistry C, 118(50), 29252-29259. https://doi.org/10.1021/jp505394e