1-Butene, hydrogenation and isomerization

The measure of activity on these pretreated catalysts gives a direct access to the real toxicity of sulfur for the specific reaction. Figure 12 emphasizes the turnover numbers of the 1-butene hydrogenation and isomerization versus the sulfur level. The sulfiding of the metal deactivates the catalyst for both reactions. Nevertheless, they are quantitatively not similarly affected the hydrogenation shows a toxicity of 5 and the izomerization of 2. The rates are not proportional to the free surface portion, which would be indicated by a toxicity of 1. The addition of one sulfur atom deactivates more than one palladium atom. 

---