Abstract
Molybdenum sulfide (MoS2) particles comminuted in a planetary ball mill dry in air at various grinding media fractions were characterized by BET surface area, element analysis, XPS, XRD and catalytic activity. Hydrogenation of 1-methylnaphthalene (1-MN) is mainly conducted to examine the catalytic activity of the comminuted MoS2 in a batch type autoclave swung at 30rpm. Relation was investigated between the characteristics of the comminuted MoS2 and apparent volume fraction of grinding media.
Specific surface area, XRD line broadening, O/Mo measured by XPS and hydrogenation of 1-MN had the maximum and S/Mo by XPS had the minimum at the apparent volume fraction of 0.72. Catalytic activity was not explained soley by the increase in surface area of the comminuted MoS2. The catalytic activity was well correlated with S/Mo and O/Mo measured by XPS, which showed that unsaturated coordination sites of Mo are active sites for hydrogenation of 1-MN. In the experimental conditions the lattice strain of (001) and (100) of the comminuted MoS2 was almost constant, whereas the crystallite size was about 1/5 of as-received MoS2 at the apparent volume fraction of 0.72.
