Abstract: The present invention is directed to a metal-promoted zeolite beta catalyst useful in the selective catalytic reduction of nitrogen oxides with ammonia in which the zeolite beta is pre-treated so as to provide the zeolite with improved hydrothermal stability. The stabilized beta zeolite is provided by incorporating into the zeolite structure non-framework aluminum oxide chains. The aluminum oxide chains can be incorporated into the zeolite structure by a unique steaming regimen or by treatment with rare earth metals, such as cerium. The treatment process is unlike well-known methods of dealuminizing zeolites for the purpose of increasing the silica to alumina ratio. In the present invention, the non-framework aluminum oxide is characterized by FT-IR by a peak at 3781±2 cm−1, which when present, stabilizes the zeolite against further dealumination such as under oxidizing and harsh hydrothermal conditions.

Abstract: The present invention is directed to a metal-promoted zeolite beta catalyst useful in the selective catalytic reduction of nitrogen oxides with ammonia in which the zeolite beta is pre-treated so as to provide the zeolite with improved hydrothermal stability.

Abstract: The present invention is directed to an iron-promoted zeolite beta catalyst useful in the selective catalytic reduction of nitrogen oxides with ammonia in which the iron-promoted zeolite beta is treated so as to provide increased amounts of the iron promoter in the form of Fe(OH).

Abstract: A gas stream containing nitrous oxide and ammonia is contacted with a catalyst composition containing a zeolite. N2O is reduced to N2 and H2O at low temperatures in a highly efficient manner. Ammonia-mediated reduction of nitrous oxide can be effectuated from gas streams having N2O concentrations as low as 1%. The gas stream may also contact a catalytic composition selective for the reduction of NOx. In this way, N2O and Nx treatment may be effectuated in a single process stream.