AVS 64th International Symposium & Exhibition
    Fundamental Discoveries in Heterogeneous Catalysis Focus Topic Thursday Sessions
       Session HC+SS-ThA

Paper HC+SS-ThA11
Defect Formation on MoS2 via Methanol to Methoxy Conversion

Thursday, November 2, 2017, 5:40 pm, Room 24

Session: Combined Experimental and Theoretical Explorations of the Dynamics of Heterogeneously Catalyzed Reactions
Presenter: Prescott Evans, University of Nebraska - Lincoln
Authors: P. Evans, University of Nebraska - Lincoln
H.K. Jeong, University of Nebraska - Lincoln
S. Beniwal, University of Nebraska - Lincoln
P.A. Dowben, University of Nebraska - Lincoln
D. Le, University of Central Florida
T.S. Rahman, University of Central Florida
Correspondent: Click to Email
Coverage dependent defect formation, via methanol adsorption on MoS2 and conversion into methoxy, was investigated utilizing scanning tunneling microscopy, photoemission and modeled by density functional theory (DFT). The adsorption of methanol on MoS2 at 110 K followed by annealing of the sample near 350 K or the adsorption of methanol on MoS2 at 350 K results in the formation of numerous point defects at the surface of the MoS2 substrate. Larger multi-point defects, nominally ~1 nm in size as well as line defects on the MoS2 sample surface become increasingly apparent with multiple cycles of methanol exposure and annealing. X-ray spectroscopy studies of the exposure of MoS2 to methanol are consistent with a conversion to methoxy, and the production of defects, based on the reaction kinematics, and the significant shifts in oxygen binding energies. The experimental results indicate a small but persistent activation energy for the reaction. The energy favorability of the combination of defect creation and methoxy formation is also suggested by density functional theory. A strongly bound methanol surface species is not favored on the defect free MoS2 surface.