Amorphous transition metal Sulfides for nitrogen reduction

The sustainability of the world’s economy and natural resources relies in the development of novel strategies for the production of commodity chemicals and fuels. Ammonia is, and will remain, a major player of the chemical industry for the preparation of fertilizers and fine chemicals. Additionally it can provide an alternative way to store renewable energy at massive scale, if simple and scalable electrochemical process become available for its production.1 Over the course of evolution a specialized class of biomolecules, the nitrogenases, has been selected by diazotrophic organisms to catalyze the dinitrogen reduction reaction (N2RR) under physiological conditions. These enzymes drive direct N2RR via multiple electron and proton transfer at remarkable transition metal sulfide cofactors. Synthetic transition metal sulfides can be viewed as mimics of these cofactors, and appear as ideal candidates for designing catalytically active materials for the electro-driven N2RR. Over the past years, the SolHyCat group has built a strong expertise in the design, synthesis and study of bioinspired protons2 and carbon dioxide3 reduction electrocatalysts. Recently, we showed that amorphous molybdenum sulfide (a-MoSx), a well-established proton reduction catalyst, possesses nitrogenase-like activity, under specific conditions. The activity of -MoSx for direct N2RR appears very low and highly dependent the experimental conditions used. During this internship we aim to confirm and further investigate the potential of for N2RR following two complementary approaches: a) tuning the composition of the material by introducing doping elements in a-MoSx and evaluating its influence on the nitrogenases-like activity of the material; b) refining the composition of the electrolyte used for N2RR in order to limit competitive processes such as proton reduction.
Related Publications:

  • D. R. MacFarlane, et al., Adv. Mater. 2020, 32, 1904804.
  • N. Coutard, N. Kaeffer, V Artero, Chem. Commun., 2016, 52, 13728.
  • S. Roy, et al., J. Am. Chem. Soc, 2017, 139, 3685.
Background and skills expected: Candidates are expected to have training in inorganic material synthesis, classical spectroscopic techniques (UV-Vis, IR, EPR…) and basic knowledge in electrochemistry.

Competences that will be acquired during the internship: The successful candidate will acquire a strong background in electrochemical techniques applied to catalysis, develop his/her skills in analytical chemistry (spectroscopy and liquid chromatography techniques) as well as in inorganic synthesis