摘要:
Catalyst articles comprising substantially only a palladium precious metal component in a first catalytic layer and a rhodium component in a second catalytic layer and related methods of preparation and use are disclosed. Also disclosed is a catalyst article comprising a first layer formed on a carrier substrate, wherein the first layer comprises a refractory metal oxide and has a surface that is substantially uniform; a second layer formed on the first layer, wherein the second layer comprises i) an oxygen storage component that is about 50-90% by weight of the second layer and ii) a palladium component in an amount of about 2-5% by weight of the second layer, wherein the palladium component is substantially the only platinum group metal component, and a palladium-free third layer comprising a rhodium component supported on a thermostable oxygen storage component which is about 80-99% by weight of the second layer. One or more improved properties are exhibited by the catalyst article.
摘要:
A stabilized metal promoted aluminosilicate zeolite, useful in the selective catalytic reduction of nitrogen oxides with ammonia, having a silica to alumina mole ratio of at least 8 and less than 30 and an FT-IR absorption peak at 3781 plus or minus 2 cm−1 which stabilizes the zeolite against further dealumination such as under oxidizing and harsh hydrothermal conditions.
摘要:
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include injecting fluid cracking catalyst particles mixed with modified fly ash particles into a flue gas stream.
摘要:
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).The stabilized zeolite is formed by cation exchange of an iron salt into a zeolite beta which has a reduced sodium content such as by exchanging a sodium beta with ammonium or hydrogen cations. A zeolite beta having a reduced carbon content and a Si/Al ratio of no more than 10 also increases the Fe(OH) content of the iron-promoted catalyst. The iron-promoted catalyst which has the iron in the form of Fe(OH) is characterized by a peak at 3680±5 cm−1 in the IR spectra.
摘要:
Catalyst articles comprising substantially only a palladium precious metal component in a first catalytic layer and a rhodium component in a second catalytic layer and related methods of preparation and use are disclosed. Also disclosed is a catalyst article comprising a first layer formed on a carrier substrate, wherein the first layer comprises a refractory metal oxide and has a surface that is substantially uniform; a second layer formed on the first layer, wherein the second layer comprises i) an oxygen storage component that is about 50-90% by weight of the second layer and ii) a palladium component in an amount of about 2-5% by weight of the second layer, wherein the palladium component is substantially the only platinum group metal component, and a palladium-free third layer comprising a rhodium component supported on a thermostable oxygen storage component which is about 80-99% by weight of the second layer. One or more improved properties are exhibited by the catalyst article.
摘要:
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include injecting fluid cracking catalyst particles into a flue gas stream.
摘要:
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 NOx treatment may be effectuated in a single process stream.
摘要:
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).The stabilized zeolite is formed by cation exchange of an iron salt into a zeolite beta which has a reduced sodium content such as by exchanging a sodium beta with ammonium or hydrogen cations. A zeolite beta having a reduced carbon content and a Si/Al ratio of no more than 10 also increases the Fe(OH) content of the iron-promoted catalyst. The iron-promoted catalyst which has the iron in the form of Fe(OH) is characterized by a peak at 3680±5 cm−1 in the IR spectra.
摘要:
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include injecting a sorbent consisting essentially of recovered and separated fluid cracking catalyst particles into a flue gas stream.
摘要:
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include injecting fluid cracking catalyst particles mixed with modified fly ash particles into a flue gas stream.