Hydrogenation is the process of adding hydrogen to organic compounds. It is done to alkenes.
Vegetable oils have alkenes in them. Alkenes are liquid and spoil easily. People making shortening add hydrogen to the alkene, turning it into an alkane. The alkanes are more solid and stable. A catalyst is used to react the hydrogen with the oil. This makes trans fats, though. Margarine is an example of a hydrogenated spread.
Other things can be hydrogenated, too. Hot nitrogen is reacted with hydrogen under high pressure with a catalyst, usually nickel to make ammonia gas.
Images for kids
Mechanism for the hydrogenation of a terminal alkene using Wilkinson's catalyst.
The transition state of two transfer-hydrogenation reactions from ruthenium-hydride complexes onto carbonyls
Selective hydrogenation of the less hindered alkene group in carvone using a homogeneous catalyst (Wilkinson's catalyst).
Partial hydrogenation of phenylacetylene using the Lindlar catalyst.
Hydrogenation of an imine using a Raney nickel catalyst, a popular heterogeneous catalyst.
Partial hydrogenation of a resorcinol derivative using a Raney-Nickel catalyst.
Hydrogenation of maleic acid to succinic acid.
In Spanish: Hidrogenación para niños