Olefin metathesis incorporates one of these named for Grubbs, and a heterogeneous one, often palladium, figures in the hydrogenation of double bonds. It is the role played by iron in the Haber process, and reagents that cannot function as these are added in stoichiometric quantities. They achieve their principal effect by introducing an additional intermediate and hence an additional transition state. They are regenerated after a reaction is complete, and organic examples of them are called enzymes. FTP, identify these 
Olefin metathesis incorporates one of these named for Grubbs, and a heterogeneous one, often palladium, figures in the hydrogenation of double bonds. It is the role played by iron in the Haber process, and reagents that cannot function as these are added in stoichiometric quantities. They achieve their principal effect by introducing an additional intermediate and hence an additional transition state. They are regenerated after a reaction is complete, and organic examples of them are called enzymes. FTP, identify these substances that lower the activation energy of a chemical reaction to increase its rate.
Olefin metathesis incorporates one of these named for Grubbs, and a heterogeneous one, often palladium, figures in the hydrogenation of double bonds.
{catalysts}