IR Spectroscopic Evidence for MoS₂ Morphology Change with Sulfidation Temperature on MoS₂/Al₂O₃ Catalyst

Low temperature CO adsorption followed by IR spectroscopy (IR/CO) characterization was used to depict the MoS 2 morphology change with sulfidation temperature on MoS 2 /Al 2 O 3 catalyst. It is found that the morphology of MoS 2 slabs on MoS 2 /Al 2 O 3 catalyst under typical sulfidation temperature range (573 to 723 K) is a truncated triangle exposing both the M-edge and S-edge. Moreover, the IR/CO data indicate that the truncation degree (ratio of S-edge/M-edge) of MoS 2 slabs gradually increases with increasing sulfidation temperature. This finding is in line with density functional theory calculation on model catalysts, providing IR evidence of MoS 2 morphology change with sulfidation temperature on an Al 2 O 3 -supported catalyst. As a further step, it is also found that the MoS 2 morphology is strongly influenced by MoS 2 –Al 2 O 3 interactions under the same sulfidation temperature.