Therefore, the selectivity seems to be related to iron loading and particle size respectively, indicating that low iron loadings lead to excellent selectivitys of the catalyst. To evaluate the activity of the catalysts per gram of active component, the reaction rate for the hydrogenation of acetylene is determined. The calculation of the reaction rates show that the catalyst with 1 wt% iron loading has the highest overall values, followed by the catalysts with 5 wt% and 10 wt% iron loading. While the catalysts with 5 wt% and 10 wt% iron loading show an approximate linear increase of the reaction rate, the Temperature / °C