Identification of Active Edge Sites for Electrochemical H2 Evolution from MoS2 Nanocatalysts
Thomas F. Jaramillo,1
Kristina P. Jørgensen,1
Jacob Bonde,1
Jane H. Nielsen,1
Sebastian Horch,2
Ib Chorkendorff1*
The identification of the active sites in heterogeneous catalysis
requires a combination of surface sensitive methods and reactivity
studies. We determined the active site for hydrogen evolution,
a reaction catalyzed by precious metals, on nanoparticulate
molybdenum disulfide (MoS
2) by atomically resolving the surface
of this catalyst before measuring electrochemical activity in
solution. By preparing MoS
2 nanoparticles of different sizes,
we systematically varied the distribution of surface sites on
MoS
2 nanoparticles on Au(111), which we quantified with scanning
tunneling microscopy. Electrocatalytic activity measurements
for hydrogen evolution correlate linearly with the number of
edge sites on the MoS
2 catalyst.
2 Center for Atomic-scale Materials Design, Department of Physics, Nano-DTU, Technical University of Denmark, DK-2800 Lyngby, Denmark.
* To whom correspondence should be addressed. E-mail: ibchork{at}fysik.dtu.dk
