Hydrogenation catalysts can be categorized into several types:
Heterogeneous Catalysts: These are solid catalysts that function in a different phase than the reactants, typically in the form of finely divided metals supported on a substrate like carbon or alumina. Examples include Raney nickel and palladium on carbon. Homogeneous Catalysts: These catalysts operate in the same phase as the reactants, usually in a solution. They often consist of metal complexes, such as Wilkinson's catalyst (RhCl(PPh₃)₃), which is used for the hydrogenation of alkenes. Biocatalysts: Enzymes that catalyze hydrogenation reactions are less common but are used in specific, often more environmentally friendly, applications.
