Advances in catalytic removal of NOx under lean-burn conditions.

The catalytic removal of NO _x under lean conditions is one of the most important targets in catalysis research. The activities of metal oxides, zeolite-based catalysts and noble metal catalysts together with the factors are influencing the selective reduction of NO _x with hydrocarbons are reviewed. The reaction mechanisms for the three types of catalysts are briefly discussed. Recent progress in combined catalyst and NO _x storage reduction catalysts is also introduced. Finally, future research directions are forecasted. [ABSTRACT FROM AUTHOR]