posted on 2016-10-03, 00:00authored byBenjamin
R. Garrett, Kevin A. Click, Christopher B. Durr, Christopher M. Hadad, Yiying Wu
Crystalline
and amorphous molybdenum sulfide (Mo–S) catalysts
are leaders as earth-abundant materials for electrocatalytic hydrogen
production. The development of a molecular motif inspired by the Mo–S
catalytic materials and their active sites is of interest, as molecular
species possess a great degree of tunable electronic properties. Furthermore,
these molecular mimics may be important for providing mechanistic
insights toward the hydrogen evolution reaction (HER) with Mo–S
electrocatalysts. Herein is presented two water-soluble Mo–S
complexes based around the [MoO(S2)2L2]1– motif. We present 1H NMR spectra
that reveal (NEt4)[MoO(S2)2picolinate]
(Mo-pic) is stable in a d6-DMSO solution
after heating at 100 °C, in air, revealing unprecedented thermal
and aerobic stability of the homogeneous electrocatalyst. Both Mo-pic
and (NEt4)[MoO(S2)2pyrimidine-2-carboxylate]
(Mo-pym) are shown to be homogeneous electrocatalysts for the HER.
The TOF of 27–34 s–1 and 42–48 s–1 for Mo-pic and Mo-pym and onset potentials of 240
mV and 175 mV for Mo-pic and Mo-pym, respectively, reveal these complexes
as promising electrocatalysts for the HER.