초록 ▼

There is presented a specially prepared catalyst and a process for the treatment of exhaust gas with that catalyst, which is useful for the selective catalytic reduction of NOx contained in the exhaust gas. An embodiment of the process of this invention comprises a catalytic stage to selectively cat

There is presented a specially prepared catalyst and a process for the treatment of exhaust gas with that catalyst, which is useful for the selective catalytic reduction of NOx contained in the exhaust gas. An embodiment of the process of this invention comprises a catalytic stage to selectively catalytically reduce NOx over a catalyst composition comprising a metal and an in-situ crystallized zeolite, ZSM-5. The catalyst of this invention may be formed into a desired shape, e.g., by extrusion, and finished in a humidified atmosphere after forming.

대표청구항 ▼

A method for treating an exhaust gas comprising NOx and ammonia, said method comprising directing the exhaust gas along with a source of oxygen over a catalyst under treating conditions effective for the selective catalytic reduction of NOx; said catalyst comprising a metal and a zeolite having the

A method for treating an exhaust gas comprising NOx and ammonia, said method comprising directing the exhaust gas along with a source of oxygen over a catalyst under treating conditions effective for the selective catalytic reduction of NOx; said catalyst comprising a metal and a zeolite having the structure of ZSM-5; said process further comprising preparing said catalyst by in-situ crystallization of an aggregate comprising ZSM-5 seeds, clay, a non-clay source of silica, and a metal oxide selected from at least one of the oxides of Groups of the Periodic Table IIIA, IB, IIB, VA, VIA, VIIA, and VIIIA, said metal oxide being present in the aggregate in an amount sufficient to produce a metal loading on the in-situ formed zeolite of between about 0.01 and about 5 wt. %, the aggregate having been calcined at a temperature greater than about 1000°C. prior to crystallization of the zeolite, the catalyst having been finished in a humidified atmosphere under conditions effective to improve the hydrothermal stability of the catalyst, the finish treatment being conducted after the zeolite has been crystallized.