LNTs operate in a cycle of two phases: the lean phase and the rich phase. During the lean phase, where excess oxygen is present, the NOx in the exhaust gas is adsorbed onto the catalyst surface, typically comprising a mixture of precious metals like platinum and alkaline-earth metals such as barium. In the rich phase, the stored NOx is released and catalytically reduced to nitrogen using a reducing agent, typically hydrocarbons, carbon monoxide, or hydrogen.
