초록 ▼

A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a ceramic substrate, an oxide support material, preferably γ-alumina, deposited on the substrate and a metal promoter or dopant introduced into the oxide support material. The metal promoters or dopants

A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a ceramic substrate, an oxide support material, preferably γ-alumina, deposited on the substrate and a metal promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium, cerium, vanadium, oxides thereof, and combinations thereof. The γ-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between about 80 to 350 m2/g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to 0.2 weight percent. In a preferred embodiment the γ-alumina is prepared by a sol-gel method, with the metal doping of the γ-alumina preferably accomplished using an incipient wetness impregnation technique.

대표청구항 ▼

A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a ceramic substrate, an oxide support material, preferably γ-alumina, deposited on the substrate and a metal promoter or dopant introduced into the oxide support material. The metal promoters or dopants

A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a ceramic substrate, an oxide support material, preferably γ-alumina, deposited on the substrate and a metal promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium, cerium, vanadium, oxides thereof, and combinations thereof. The γ-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between about 80 to 350 m2/g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to 0.2 weight percent. In a preferred embodiment the γ-alumina is prepared by a sol-gel method, with the metal doping of the γ-alumina preferably accomplished using an incipient wetness impregnation technique. ein the catalyst comprises from about 0.5 to 5 mass-% sulfur on an elemental basis. 19. The catalyst of claim 14 wherein the refractory inorganic-oxide binder comprises alumina. 20. The catalyst of claim 14 wherein the first component consists essentially of one single lanthanide element component or a yttrium component and the second component consists essentially of one single metal selected from the platinum-group metals. 21. The catalyst of claim 14 wherein the first component is selected from the group consisting of lutetium, ytterbium, thulium, erbium, holium, terbium, combinations thereof, and yttrium. 22. The catalyst of claim 14 wherein the first component is ytterbium. 23. The catalyst of claim 14 further comprising a third component selected from the group consisting of iron, cobalt, nickel, rhenium, and mixtures thereof. 24. The catalyst of claim 23 wherein the third component is iron in an amount from about 0.1 to about 5 wt. %. 25. The catalyst of claim 14 wherein the second component is platinum. 26. A catalyst comprising a support comprising a sulfated oxide or hydroxide of at least one of the elements of Group IVB (IUPAC 4) of the Periodic Table, having deposited thereon; a first component first component consists essentially of one single lanthanide element component or a yttrium component and the second component consists essentially of one single metal selected from the platinum-group metals.