Oxygen storage material without rare earth metals
The present disclosure relates to an enhanced oxygen storage material (OSM) that may be converted into powder form and used as a raw material for a vast number of applications, and more particularly in catalyst systems. The disclosed OSM, substantially free from PGM and rare earth (RE) metals, has significantly higher oxygen storage capacity (OSC) than conventional OSM including PGM and RE metals. The disclosed OSM may be converted into powder, including a formulation of Cu—Mn spinel structure deposited on Nb—Zr oxide support. The disclosed OSM may also be coated onto a ceramic substrate as washcoat layer for characterization under OSC isothermal oscillating condition. The disclosed OSM may have an optimal OSC property that increases with the temperature, showing acceptable level of O 2 storage even at low temperatures.
1 . A catalyst system, comprising:
a substrate; and
at least one oxygen storage material that is substantially free of platinum group metals;
wherein the at least one oxygen storage material comprises at least one of CuMn 2 O 4 , Nb 2 O 5 —ZrO 2 , and combinations thereof.
2 . The catalyst system of claim 1 , wherein the CuMn 2 O 4 is in a spinel phase.
3 . The catalyst system of claim 1 , wherein the Nb 2 O 5 —ZrO 2 comprises about 15% to about 30% by weight of Nb 2 O 5 .
4 . The catalyst system of claim 1 , wherein the Nb 2 O 5 —ZrO 2 comprises about 25% by weight of Nb 2 O 5 .
5 . The catalyst system of claim 1 , wherein the Nb 2 O 5 —ZrO 2 comprises about 70% to about 85% by weight of ZrO 2 .
6 . The catalyst system of claim 1 , wherein the Nb 2 O 5 —ZrO 2 comprises about 75% by weight of ZrO 2 .
7 . The catalyst system of claim 1 , wherein the at least one oxygen storage material is deposited on the substrate at about 120 g/L.
8 . The catalyst system of claim 2 , wherein the Cu—Mn spinel structure comprises about 10 g/L to about 15 g/L of Cu.
9 . The catalyst system of claim 2 , wherein the Cu—Mn spinel structure comprises about 20 g/L to about 25 g/L of Mn.
10 . The catalyst system of claim 1 , wherein the Nb 2 O 5 —ZrO 2 is deposited on the substrate at about 80 g/L to about 90 g/L.
11 . The catalyst system of claim 1 , wherein the at least one oxygen storage material is substantially free of rare earth metals.
12 . The catalyst system of claim 1 , where in the O 2 delay time is about 40 seconds at about 300° C.
13 . The catalyst system of claim 1 , where in the O 2 delay time is about 60 seconds at about 400° C.
14 . The catalyst system of claim 1 , wherein the at least one oxygen storage material is at least partially aged.
15 . The catalyst system of claim 14 , wherein the aging is hydrothermal aging.
16 . The catalysts system of claim 2 , wherein the CuMn 2 O 4 is heated to about 600° C.
17 . The catalyst system of claim 1 , wherein the at least one oxygen storage material is applied to the substrate by co-precipitation.
18 . The catalyst system of claim 1 , wherein the at least one oxygen storage material is applied to the substrate as a powder.
19 . The catalyst system of claim 1 , wherein the at least one oxygen storage material stores O 2 at a concentration of about 2,000 ppm.
20 . The catalyst system of claim 1 , wherein the at least one oxygen storage material stores CO at a concentration of about 4,000 ppm.