Method for producing a multicomponent alloy

Abstract

Disclosed herein is a catalyst including a multicomponent alloy including a seed and al least four elements. The seed includes at least one platinum group metal, wherein the platinum group metal includes platinum, ruthenium, iridium, palladium, or rhodium. Methods of preparing the catalyst are also provided herein.

Description

METHOD FOR PRODUCING A MULTICOMPONENT ALLOYCROSS REFERENCE TO RELATED APPLICATION(S)

[0001] The present application claims priority to U.S. Provisional Patent Application No. 63 / 546.074 filed on October 27, 2023, the entire contents of which is incorporated in its entirety.FIELD OF THE INVENTION

[0002] Disclosed herein is a catalyst including a multicomponent alloy including a seed and at least four elements, wherein the seed includes at least one platinum group metal. Specifically, the platinum group metal may include platinum (Pt), ruthenium (Ru), iridium (Ir), palladium (Pd), or rhodium (Rh).BACKGROUND

[0003] Catalysts including a noble-metal suffer from effects of aging resulting in reduced activity and / or selectivity over time. Thus, a noble-metal catalyst is known to deactivate over time. It is believed that catalytic deactivation results from thermal and chemical mechanisms. A major factor of thermal deactivation is the sintering of noble metal particles, which is known to depend on the ageing temperature and the oxygen concentration in the exhaust gas. Chemical deactivation is mainly caused by the poisoning, which has two effects on the catalyst deactivation. One effect is the loss of the catalyst activity, which is expressed by reducing frequency factors of reaction rates. Another effect is the suppression of the noble metal sintering. To address this, multimetallic alloys have been developed. However, one of the major challenges for these materials is their synthesis / production at the nanoscale. This is crucial step for the performance and applicability of this class as catalytic materials.

[0004] Therefore, there is need to develop a method to prepare a catalyst including multicomponent alloy nanoparticles include multiple metal elements as active sites.SUMMARY

[0005] Disclosed herein in an embodiment is a catalyst. In an embodiment, the catalyst includes a multicomponent alloy comprising a seed and at least four elements, and wherein the seed comprises at least one platinum group metal, wherein the at least one platinum group metal includes platinum (Pt), ruthenium (Ru). iridium (Ir), palladium (Pd), or rhodium (Rh).

[0006] In some embodiments of the catalyst, the at least four elements may include iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), vanadium (V), manganese (Mn), molybdenum (Mo), ruthenium (Ru), platinum (Pt), palladium (Pd), rhodium (Rh), chromium (Cr), tin (Sn), iridium (Ir), tungsten (W), indium (In), silver (Ag), zirconium (Zr), cerium (Ce), yttrium (Y), gold(Au), or a combination thereof.

[0007] In some embodiments, the at least four elements may be selected from Fe, Co, Ni, Cu. Zn. V. Mn, Mo, Ru, or Cr.

[0008] In some embodiments, the at least four elements may include eight elements selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, W, In, Ag, Zr, Ce, Y, or a combination thereof.

[0009] In some embodiments, the at least four elements may include ten elements selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, W, In, Ag, Zr, Ce, Y, or a combination thereof.

[0010] In some embodiments of the cataly st, the seed may include Pt or Ru. In some embodiments, the Pt may be included in an amount of about 0. 1 wt% to about 1 wt%. In some embodiments, the Ru may be included in an amount of about 0. 1 wt% to about 1 wt%

[0011] In some embodiments, the seed may have a particle size of about 2 nm to about 50 nm.

[0012] In some embodiments, the catalyst may have a core and a shell. In some embodiments, the core may include the multicomponent alloy.

[0013] In some embodiments, the catalyst may further include a support. In some embodiments, the support may include an inorganic oxide, carbide, zirconia, alumina, or nitride material. In some embodiments, the support may include AI2O3, TiCh. T Ch, T Os. Ti40v. TiC, ZrC, HfC, TaC, TiN, ZrN, HfN, TaN, boron carbide, boron-oxy-carbide, doped SnCh. undoped SnCh, doped carbon, undoped carbon, SiCh, undoped ZrCh, doped ZrCh or a combination thereof.

[0014] In some embodiments of the catalyst, the at least four elements may be equimolar.

[0015] In some embodiments, the catalyst may be prepared through colloidal synthesis. In some embodiments, the colloidal synthesis may be prepared at a temperature from about 250°C to about 400°C.

[0016] In some embodiments, the catalyst may include uniform distribution of the seed and at least four elements.

[0017] In another embodiment, a method of performing a reaction is provided. The method of performing a reaction may include applying the catalyst according to the present disclosure.

[0018] In some embodiments, the reaction may include oxidation or reduction of carbon monoxide.

[0019] In some embodiments, the reaction may include oxidation or reduction of nitric oxide.

[0020] In some embodiments, the reaction may include oxidation or reduction of a hydrocarbon.

[0021] In some embodiments, the rection may include oxidation or decomposition of ammonia.

[0022] In some embodiments, a method of preparing a catalyst is provided. The method of preparing a catalyst includes mixing a seed and at least four elements to form a mixture, wherein the seed comprises platinum-group metals: platinum (Pt), ruthenium (Ru), iridium (Ir), palladium (Pd) or rhodium (Rh) ; heating the mixture: and applying a gas to the mixture.

[0023] In some embodiments of the method, the heating may occur at a temperature of about 250°C to about 800°C. In some embodiments, the gas may include nitrogen, argon or steam. In some embodiments, steam may be applied for about 4 hours to about 10 hours.

[0024] In some embodiments of the method, the at least four elements may include iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), vanadium (V), manganese (Mn), molybdenum (Mo), ruthenium (Ru), platinum (Pt), palladium (Pd), rhodium (Rh). chromium (Cr), tin (Sn), iridium (Ir), tungsten (W), indium (In), silver (Ag), zirconium (Zr), cerium (Ce), yttrium (Y), or a combination thereof. In some embodiments, the at least four elements may be selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, or Cr. In some embodiments, the at least four elements may include eight elements selected from Fe, Co, Ni, Cu, Zn. V, Mn. Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, W, In, Ag, Zr, Ce, Y, or a combination thereof. In some embodiments, the at least four elements may include ten elements selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, W, In, Ag, Zr, Ce, Y, or a combination thereof.

[0025] In some embodiments, the seed may include Pt or Ru. In some embodiments, the Pt may be included in an amount of about 0. 1 wt% to about 1 wt%. In some embodiments, the Ru may be included in an amount of about 0.1 wt% to about 1 wt%.

[0026] In some embodiments, the catalyst may be stable for at least about 12 hours. In some embodiments, the seed and the at least four elements are uniform within the catalyst of the method.

[0027] In some embodiments of the method, the catalyst may have a core and a shell.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The disclosure described herein is illustrated by way of example and not by way of limitation in the accompanying figures.

[0029] Figure 1 is a STEM-EDS mapping illustrating the compositional homogeneity of HEA-NP samples.

[0030] Figure 2 represents a result of a stability study of an HEA-NP sample compared to a Pt-Np sample.

[0031] Figure 3 is a lightoff curve (LOC) analysis according to an embodiment of the present disclosure.

[0032] Figure 4 is the results of CO oxidation kinetic study.

[0033] Figure 5 is images of the Pt and PtCoNiCuZn NP after ‘"oxidizing steam" treatment in a tube furnace: 4% H2O, 5% O2, 600 °C, 6 h

[0034] Figure 6 illustrates the result of the mean NP diameter vs calcination temperature using “oxidizing steam” conditions 4% H2O, 5% 02; 50 seem. Red dots are Pt NP and blue dots PtCoNiCuZn NP.

[0035] Figure 7 illustrates the results of a comparative example using metal salts.

[0036] Figure 8 demonstrates the colloidal synthesis of multicomponent alloys including PtFeCoNiW.

[0037] Figure 9 illustrates the EDS spectra of PtFeCoNiW according to an example.

[0038] Figure 10 is an X-ray diffraction of PtFeCoNiW nanocrystals.

[0039] Figure 1 1 is a selected area electron diffraction of PtFeCoNiW nanocrystals

[0040] Figure 12 illustrates the results of a machine learning based model.

[0041] Figure 13 illustrates the versatility of synthesis method using different size and seed.

[0042] Figure 14 illustrates the results of stability and catalytic activity of nanoparticles according to an embodiment.

[0043] Figure 15 is TEM images of various Pt based catalysts.

[0044] Figure 16 illustrates the results of synthesis of a Ru-seed nanoparticle according to an embodiment.

[0045] Figure 17 illustrates the results of a machine learning based model of a Ru-seed embodiment.

[0046] Figure 18 illustrates the results of performing a reaction using a Ru-based catalyst according to the Examples.

[0047] Figure 19 illustrates the results of the comparative Ru catalyst.

[0048] Figure 20 illustrates the conversion results of the various catalysts at different temperatures.

[0049] Figure 21 illustrates the EDS map of RuCoFeMnW according to an embodiment.Detailed Description

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0051] As used herein, "‘a” or "an" entity refers to one or more of that entity, e.g., ‘’a compound” refers to one or more compounds or at least one compound unless stated otherwise. As such, the terms “a” (or “an”), “one or more”, and “at least one” are used interchangeably herein.

[0052] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Additionally, as used herein, “or” means “and / or.”

[0053] As used herein, the term “multicomponent” refers to a composition including more than one element, or metal.

[0054] A multicomponent alloy, such as a high entropy alloy (HEA). nanoparticles are an emerging class of nanomaterials that may be used in a variety of different fields, including catalysis. It has been found that by incorporating five or more elements or metals in a single particle generates a considerable configurational entropy. This configurational entropy can dominate the particle’s thermodynamic behavior, can stabilize the alloyed structure, and / or can mitigate any structural in an acidic environment. Additionally, a multicomponent alloy may manifest a mixing effect where a synergistic response arising from the mutual electronic interactions between its constituent elements is observed. It has further been found that the availability of multi-element active sites on the surface of HEA nanoparticles make HEA a suitable platform to facilitate a catalyst reaction. The present disclosure relates to a multicomponent alloy, such as a high entropy alloy, that includes a seed and at least four elements, where the seed includes at least one platinum group metal including platinum (Pt), ruthenium (Ru), iridium (Ir), palladium (Pd), or rhodium (Rh). The catalyst described herein has been found to be useful in environmental catalyst, oxidation reactions, dehydrogenationreactions, or in electrocatalysis. Additionally, the catalysis including a multicomponent alloy including a seed and at least four elements may be prepared by heating a mixture of seed and the at least four elements and applying a gas to the mixture.

[0055] In an embodiment of the present disclosure, a catalyst including a multicomponent alloy is provided. The multicomponent alloy may include a seed and at least four elements. The seed may include at least one platinum group metal, wherein the at least one platinum group metal includes platinum (Pt), ruthenium (Ru), iridium (Ir). palladium (Pd), or rhodium (Rh).

[0056] In some embodiments, the at least four elements may include iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), vanadium (V), manganese (Mn), molybdenum (Mo), ruthenium (Ru), platinum (Pt), palladium (Pd), rhodium(Rh), chromium (Cr), tin (Sn), iridium (Ir), silver (Ag), zirconium (Zr), cerium (Ce), yttrium (Y), or a combination thereof.

[0057] In some embodiments, the at least four elements may be selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Cr, or a combination thereof.

[0058] In some embodiments, the at least four elements include eight elements. The eight elements may be selected from Fe, Co, Ni, Cu, Zn, V. Mn, Mo. Ru, Pt. Pd. Rh. Cr. Sn. Ir, Ag. Zr, Ce, or Y. In some embodiments, the eight elements may be V, Mn, Fe, Co, Ni, Cu, Mo and Ru.

[0059] In another embodiment, the at least four elements may include ten elements. The ten elements may be selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo. Ru, Pt. Pd. Rh, Cr, Sn, Ir, Ag, Zr, Ce, or Y. In some embodiments, the ten elements may be V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo and Ru.

[0060] In some embodiments, the multicomponent alloy may include a seed and 4 elements. In another embodiment, the multicomponent alloy may include a seed and 6 elements. In other embodiments, the multicomponent alloy may include a seed and 8 elements. In some embodiments, the multicomponent alloy may include a seed and 10 elements. In other embodiments, the multicomponent alloy may include a seed and 12 elements. In another embodiment, the multicomponent alloy may include a seed and 14 elements. In yet another embodiment, the multicomponent alloy may include a seed and 18 elements. In some embodiments, the multicomponent alloy may include a seed and at least 4 elements, at least 6 elements, at least 8 elements, at least 10 elements, at least 14 elements, or at least 18 elements.

[0061] In some embodiments, the seed of the multicomponent alloy may include Pt. In an embodiment, the Pt may be included in an amount of about 0. 1 wt% to about 1 wt%. In someembodiments, the Pt may be included in an amount of about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, about 0.4 wt%, about 0.5% wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 \\t% or about 1 wt%. In other embodiments, the Pt may be included in an amount of about 0. 1 wt% to about 1 wt%, about 0.2 wt% to about 0.9 wt%, about 0.3 wt% to about 0.8 wt%, or about 0.4 wt% to about 0.7 wt%.

[0062] In some embodiments, the seed of the multicomponent alloy may be a nanoparticle. In some embodiments, the seed may have a particle size of about 2 nm to about 50 nm. In another embodiment, the particle size of the seed may be about 2 nm to about 50 nm, about 5 nm to about 45 nm, about 10 nm to about 40 nm, about 15 nm to about 35 nm, or about 20 nm to about 30 nm. In other embodiments, the particle size of the seed may be about 2 nm, about 5 nm, about 10 nm, about 12 nm, about 15 nm, about 20 nm, about 25 nm, about 30 nm, about 35 nm, about 40 nm, about 45 nm, or 50 nm.

[0063] In some embodiments, the catalyst may have a core and a shell. In some embodiments, the core may include the multicomponent alloy including the seed and at least four elements. In some embodiments, the seed in the core may include at least one platinum group metal, wherein the at least one platinum group metal includes Pt. Ru. Ir, Pd, or Rh. In some embodiments, the at least four elements in the core may be selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, Ag, Zr, Ce, or Y. In an embodiment, the at least four elements in the core may be Fe, Ni, Cu. and Co. In another embodiment, the at least for elements in the core may be Co, Ni, Cu. and Zn.

[0064] In some embodiments, the catalyst may further include a support. The support may be any suitable carrier material as known in the art. In some embodiments, the support may include an inorganic oxide, carbide zirconia, alumina or nitride material. For example, the support may be titanium suboxides (T1O2. TizOs, TisOs. and Ti4O?),TiC, ZrC, HfC, TaC. TiN, ZrN, HfN, TaN, boron carbide, boron-oxy -carbide, doped SnCh, undoped SnCh. doped carbon, undoped carbon, SiCh, undoped ZrCh, doped Zr(h, or a combination thereof.

[0065] In some embodiments, the at least four metals of the multicomponent alloy are equimolar.

[0066] In some embodiments, the catalyst may be prepared through colloidal synthesis. In an embodiment, the colloidal synthesis may be performed at a temperature from about 250°C to about 400°C. In other embodiments, the colloidal synthesis may be performed at a temperature of about 250°C, about 275°C, about 300°C, about 325°C, about 350°C, about 375°C, or about 400°C.

[0067] In some embodiments, the catalyst may include uniform distribution of the seed and the at least four elements.

[0068] In another embodiment, a method of performing a reaction may include applying the catalyst according to the present disclosure. The catalyst includes a multicomponent alloy including a seed and at least four elements, wherein the seed includes at least one platinum group metal. In some embodiments, the reaction may include propane conversion including applying steam and cracking ammonia. In another embodiment, the reaction may include oxidation or reduction of carbon monoxide. In other embodiments, the reaction may include oxidation or reduction of nitric oxide In another embodiment, the reaction may include oxidation or reduction of a hydrocarbon. In yet another embodiment, the reaction may include oxidation or decomposition of ammonia.

[0069] In another embodiment of the present disclosure, a method of preparing a catalyst is provided. The method may include mixing a seed and at least four elements, wherein the seed includes at least one platinum group metal. The at least one platinum group metal may include Pt, Ru, Ir, Pd, or Rh. The method may further include heating the mixture and applying a gas to the mixture. Without being bound to a theory, the present inventors have found that by heating and applying a gas to the mixture enhances the activity of the catalyst. They believe that this occurs because the platinum migrates to the surface of the catalyst structure.

[0070] In some embodiments of the method, the heating may occur at a temperature of about 250°C to about 800°C, about 300°C to about 750°C, about 350°C to about 700°C, about 400°C to about 650°C, or about 450°C to about 600°C. In other embodiments, the heating may occur at a temperature of about 250°C, about 275°C, about 300°C, about 325°C, about 350°C, about 375°C, about 400°C, about 425°C, about 450°C, about 475°C, about 500°C, about 525°C, about 550°C, about 575°C, about 600°C, about 625°C, about 650°C, about 675°C, about 700°C, about 725°C, about 750°C, about 775°C, or about 800°C.

[0071] In some embodiments of the method, the gas may include nitrogen, argon, or steam. In some embodiments, the steam may be applied for about 4 hours to about 10 hours, about 5 hours to about 9 hours, or about 6 hours to about 8 hours. In another embodiment, the steam may be applied for about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, or about 10 hours.

[0072] In some embodiments of the method, the at least four elements may include Fe, Co, Ni, Cu, Zn. V, Mn. Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, Ag, Zr, Ce, Y, or a combination thereof. In some embodiments, the at least four elements may be selected from Fe, Co, Ni, Cu, Zn, V, Mn,Mo, Ru, Cr, or a combination thereof. In some embodiments, the at least four elements include eight elements. The eight elements may be selected from Fe, Co. Ni. Cu. Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, Ag, Zr, Ce, or Y. In some embodiments, the eight elements may be V, Mn, Fe, Co, Ni, Cu, Mo and Ru. In another embodiment, the at least four elements may include ten elements. The ten elements may be selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, Ag. Zr. Ce, or Y. In some embodiments, the ten elements may be V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo and Ru.

[0073] In some embodiments, the seed of the multicomponent alloy may include Pt. In an embodiment, the Pt may be included in an amount of about 0. 1 wt% to about 1 wt%. In some embodiments, the Pt may be included in an amount of about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, about 0.4 wt%, about 0.5% wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt% or about 1 wt%. In other embodiments, the Pt may be included in an amount of about 0. 1 wt% to about 1 wt%, about 0.2 wt% to about 0.9 wt%, about 0.3 wt% to about 0.8 wt%, or about 0.4 wt% to about 0.7 wt%. It has been found that as the amount of elements increase in the multicomponent alloy, that the relative Pt amount decreases.

[0074] In some embodiments, the catalyst may be stable for at least about 12 hours. In an embodiment, the catalyst may be stable for about 12 hours, about 14 hours, about 16 hours, about 18 hours, about 20 hours, about 22 hours, about 24 hours, about 30 hours, about 36 hours, about 42 hours, or about 48 hours.

[0075] In some embodiments of the method, the seed and the at least four elements may be uniform within the catalyst. In some embodiments, the catalyst may have a core and a shell. In some embodiments, the core may include the multicomponent alloy including the seed and at least four elements. In some embodiments, the seed in the core may include at least one platinum group metal, wherein the at least one platinum group metal includes Pt, Ru, Ir, Pd, or Rh. In some embodiments, the at least four elements in the core may be selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, Ag, Zr, Ce, or Y. In an embodiment, the at least four elements in the core may be Fe, Ni, Cu, and Co. In another embodiment, the at least for elements in the core may be Co, Ni, Cu, and Zn.

[0076] In some embodiments, the catalyst may further include a support. The support may be any suitable carrier material as known in the art. In some embodiments, the support may include an inorganic oxide, carbide zirconia, alumina or nitride material. For example, the support may be titanium suboxides (TiCh, Ti2C>3, TisOs. and Ti4O?),TiC, ZrC, HfC, TaC, TiN,ZrN, HfN, TaN, boron carbide, boron-oxy -carbide, doped SnCh. undoped SnCh, doped carbon, undoped carbon, SiCh. undoped ZrCh. doped ZrCh. or a combination thereof.

[0077] In an embodiment, the catalyst may be prepared according to an additional method. The method may include reacting a seed including at least one platinum group metal and at least four elements having a formula according to Formula 1 with a reductant, surfactant or combination thereof.Formula 1 : Ml Rm, M2Rm, M3Rm. M4Rm. . . .MnRm wherein, M = a metal selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, Ag, Zr, Ce, or YR = -acac, or -OAc m = 1, 2, 3 n = an integer of 4 or greater

[0078] In another embodiment, the at least four elements may have a formula according to Formula 2.Formula 2: XM(R)ywherein, X = an integer from 5 to 15M = V, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Ag, In, W, Ir, or PtR = -OAc, -acac, or CO y = an integer from 2 to 6

[0079] In some embodiments, the at least one platinum group metal includes Pt, Ru, Ir, Pd, or Rh. In some embodiments, the reductant or surfactant may include oleylamine (OLAM).

[0080] In some embodiments, the reacting may occur for about 10 minutes to about 2 hours. In other embodiments, the reacting may occur for about 10 minutes, about 20 minutes, about 30 minutes, about 40 minutes, about 50 minutes, about 60 minutes, 70 minutes, about 80 minutes, about 90 minutes, about 100 minutes, about 110 minutes, or about 120 minutes.

[0081] In some embodiments, the reacting may occur at a temperature of about 100°C to about 400°C, about 125°C to about 375°C, about 150°C to about 350°C, about 175°C to about 325°C, or about 200°C to about 300°C.

[0082] In some embodiments, the catalyst may be stable for at least about 12 hours. In some embodiments, the catalyst may be stable for about 12 hours, about 13 hours, about 14 hours, about 15 hours, about 16 hours, about 17 hours, about 18 hours, about 20 hours, about 21 hours, about 22 hours, about 23 hours, about 24 hours, about 28 hours, about 32 hours, or about 36 hours.

[0083] In some embodiments, the catalyst may have a particle size between about 2 nm to about 50 nm. In other embodiments, the particle size may be between about 2 nm to about 45 nm, about 5 nm to about 40 nm, about 10 nm to about 35 nm, about 15 nm to about 30 nm, or about 20 nm to about 25 nm. In other embodiments, the particle size distribution may be about 2 nm, about 5 nm, about 10 nm, about 15 nm, about 20 nm, about 25 nm, about 30 nm, about 35 nm, about 40 nm, about 45 nm. or about 50 nm.

[0084] Claims or descriptions that include “or” or “and / or” between at least one members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The disclosure includes embodiments in which exactly one member of the group is present in. employed in, or otherwise relevant to a given product or process. The disclosure includes embodiments in which more than one, or all the group members are present in, employed in, or otherwise relevant to a given product or process.

[0085] Furthermore, the disclosure encompasses all variations, combinations, and permutations in which at least one limitation, element, clause, and descriptive term from at least one of the listed claims is introduced into another claim. For example, any claim that is dependent on another claim can be modified to include at least one limitation found in any other claim that is dependent on the same base claim. Where elements are presented as lists, such as, e.g.. in Markush group format, each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should be understood that, in general, where the disclosure, or aspects of the disclosure, is / are referred to as comprising particular elements and / or features, embodiments of the disclosure or aspects of the disclosure consist, or consist essentially of, such elements and / or features. For purposes of simplicity, those embodiments have not been specifically set forth in haec verba herein. Where ranges are given (such as, e.g., from [X] to [Y]), endpoints (such as, e.g., [X] and [Y] in the phrase “from [X] to [Y]”) are included unless otherwise indicated. Furthermore, unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or sub-range within the stated ranges in different embodiments of the disclosure, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise.

[0086] Those of ordinary skill in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein. Such equivalents are intended to be encompassed by the following claims.EXAMPLES

[0087] The following examples are intended to be illustrative and are not meant in any way to limit the scope of the disclosure.

[0088] A variety of comparative examples of different catalysts were prepared along with a catalyst including a HEA of the present disclosure.Synthesis of Colloidal NanoparticlesGeneral Synthesis of HEA-nanoparticle at 350°C

[0089] A robust seed-mediated colloidal synthesis had been developed, as described in the present disclosure. The colloidal synthesis was found to form relatively uniform and monodisperse high entropy alloy-nanoparticles (HEA-NPs) containing various combinations of at least 5 elements, having as many as 15 or more elements. Platinum (Pt) and ruthenium (Ru) nanoparticles were prepared as seeds having a particle size of 5 nm, and 4 nm, respectively. The seeds were added to a suspension of M(acac)x in oleylamine (OLAM). Dissolved traces of oxygen (O2) and water (H2O) were removed from the mixture through degassing under dynamic vacuum for 30 minutes at 100°C. Next, the reaction mixture was placed under nitrogen (N2) and ramped up to 10°C / min to 350°C. After stirring at 350°C for 30 minutes, the solution was rapidly cooled to 80°C. The final nanoparticles were isolated with sequential washes with isopropanol followed by resuspension of colloidal nanoparticles (NPs) in either hexanes or toluene.Synthesis of Core-Shell Nanoparticles at 280°C

[0090] An analogous seed-mediated preparation and workup of a sample prepared from Pt seeds, having a particle size of 5 nm, mixed with acetylacetonate salts of Fe, Co, Ni, and Cu was heated to and held at 280°C for 30 minutes, which led to the formation of clearly phase- separated core-shell (Pt)(FeCoNiCu) nanoparticles. The contrast in nanoparticle structure for PtFeCoNiCu samples prepared at either 280°C or 350°C highlight the structural sensitivity of the seed-mediated approaches.Differentiating synthesis temperatures

[0091] The present inventors, without being bound to a theory, attribute a greater degree of atomic mixing to the higher reaction temperature, 350°C. To study the evolution of nanoparticle structure over time, samples of the reaction mixture containing Pt seeds having a particle size of 5 nm, M(acac)2 (M= Fe, Co, Ni, Cu) were prepared and quenched.Characterization of Nanoparticles

[0092] STEM-EDS mapping was performed to confirm the compositional homogeneity of HEA-NP samples as shown in Figure 1.

[0093] For the PtFeCoNiCu-NP sample, the nanoparticles w ere found to uniformly feature a PtCoNi-rich core phase separated from FeCu-rich shells. Though incorporating the theoretical minimum number of elements needed to reach a high entropy mixing state, enthalpically favored phase separation leads to the observed phase separation.

[0094] Additionally studies are being conducted related to Platinum seeds with different elements and having different radii.Stability of HEA nanoparticle

[0095] A stability study was performed to compare a PtCoNiCuZn / AI2O3 nanoparticle prepared according to the method described herein to a Pt / AI2O3 nanoparticle. During this study, each sample was treated at a temperature of 600°C, 650°C, and 700°C for 6 hours with 2.6% FEO and 5% O2 (4% steam). From this study we concluded that the multimetallic nanoparticles are more stable than the single metal Pt nanoparticles prepared using the same synthetic method. Only marginal growth of PtCoNiCuZn NP on AI2O3 was observed under the stated conditions at 600°C and 650°C whereas an analogous Pt NP on AI2O3 sample nearly 3x in mean diameter at 600°C and 4x in mean diameter at 650°C. It was found that the mean diameter of PtCoNiCuZn NP on AI2O3 doubles upon treatment at 700°C, while the average NP mean diameter was nearly 2x smaller than analogously prepared / treated Pt / NPs on AI2O3. These observations indicate a lower propensity for the PtCoNiCuZn NPs to sinter relative to related noble metal Pt NP catalysts of a similar mean diameter. These observations can be seen in Figures 5 and 6.Increase number of elements in HEA-NP

[0096] Additional studies were run to increase the alloy entropy of mixing by studying the synthesis of including 6 to 19 elements in the nanoparticles. EDS mapping and line scan analysis were performed on these examples. It was found that the bimodal PtVMnFeCoNiCoMoRu (9 element) HEA-NP had an average particle size of 8 nanometers and possessed a more uniform distribution of elements through the nanoparticle structure when compared to 5 element nanoparticle.Activity of HEA-NPs

[0097] The activity of PtCoNiCuZn verse Pt having a particle size of 5 nm for propene oxidation was studied. An important advantage of developing a colloidal HEA-NP synthesis is the ability to select from a variety of high surface area metal-oxide supports prevalent in thermocatalytic applications. A sample including colloidally synthesized PtCoNiCuZn was prepared to be supported on AhOs. The PtCoNiCuZn- AI2O3 catalyst was prepared with a 0.3 wt% Pt, which enabled its comparison against to a standard Pt-AhCh (0.3 wt%) on a per-Pt basis. A lightoff curve (LOC) analysis typical in assessing thermocatalytic materials was used to establish an initial comparison as can be seen in Figure 2. The colloidal synthesis HEA-NP had a rather high temperature of half conversion, which indicates rather poor catalytic activity when compared to Pt-A12O3 sample. However, it was found that the HEA NP in reaction gases at 600°C for 2 hours lead to pronounced improvement of catalytic activity. Moreover, preparation of the HEA catalyst through a steam treatment leads to an even more favorable temperature of half conversion, being similar to that of Pt-A12O3. However, the steam-treated Pt-A12O3 performed more poorly.Structural Dynamics

[0098] The pronounced differences in PtCoNiCuZn-AECh activity based on aging and catalyst preparation environments indicates a degree of dynamic structural rearrangement under these conditions. Previously, structural dynamics have been demonstrated in a variety of multimetallic nanoparticles containing 2 or 3 metals. Recent findings suggest that high entropy alloy nanoparticle structures can dynamically rearrange, which challenges previous convention that the sluggish atomic diffusion of high entropy of mixing in high entropy alloys provides static structures as seen in Skrabalak and TEM oxidation / reduction paper. In contrast, the present disclosure suggests dynamic structural behavior, providing the opportunity to increase the understanding of dynamic behavior of these catalysis under thermocatalyticconditions. Part of this includes structural evolution leading to migration of Pt to surface active sites, and / or the structure rearranges surface elements to become more active for propene oxidation.

[0099] TEM images were taken for a freshly prepared catalyst, reaction aged catalyst, steam-treated catalyst, and a steam-treated and aged catalyst for both PtCoNiCuZn-AhCh and Pt-AhCh samples. The size distribution of PtCoNiCuZn-AhCh and Pt-AbOs samples were treated in H2O and 5% O2 at 600°C, 650°C. 700°C, and 750°C by ex-situ TEM. Importantly, it was found that Pt (5nm) nanoparticles dramatically sinter, leading to a 4x increase in average nanoparticle diameter, where as PtCoNiCuZn nanoparticles experience only a marginal increase in average diameter. This indicated a pronounced increase in thermal stability of the high entropy alloy nanoparticle sample relative to its precious metal counterpart.CO Oxidation Kinetic Study[000100] A study was conducted to analyze the kinetics of CO oxidation of a Pt catalyst compared to a steam treated catalyst in accordance with the present disclosure. The reaction condition of the study was as follows: CO 0.4%, O2 4% with pure Ar, Flow Rate: 50 mL / min, Catalyst 30 mg + AI2O3 170 mg. The catalysts underwent the following pretreatment: O2 5%, 50 mL / min, 300°C, 30 min + Eh 5%, 50 mL / min, 300°C, 30 min or H2O 4.2% 600°C 2 hour 50 mL / min. The results of this study is shown in Figure 4.Additional Study for synthesis of colloidal nanoparticles[000101] An additional study was conducted to prepare and analyze preparing colloidal nanoparticles including five or more metals. Previously, because of the complexity' of synthesis of these particles, few synthetic methods for preparing multimetallic nanoparticles have been reported. However, the past methods have not been successful because they cannot control the size and shape of the nanocrystals. Thus, the present inventors have found that seed-mediated co-reduction methods could be applied to control the size and shape of the nanoparticles and / or nanocrystals. Here, three different metals were reduced and deposited on pre-synthesized bimetallic nanocrystals, forming core-shell multimetallic nanocrystals. Then the nanocrystals were deposited on support materials and exposed to high temperatures to form the multicomponent alloy. In this study, a robust method to synthesize the multicomponent alloy and multimetallic nanocrystals with five elements including one noble metal was developed utilizing a seed-mediated growth method. Various compositions of Pt-based multicomponentalloy with uniform sizes and shapes were synthesized in the present study. Machine learning based simulations were used to calculate the tendency of phase segregation and analyze the proper compositions that can form the high entropy alloy. Though Pt was test, the inventors believe that Au and Pd could also be used as a seed material to form the multicomponent alloy. [000102] The multicomponent alloys prepared in the study were also tested as catalytic materials for CO and CsHe oxidation reactions. From this study, both catalysts initially showed similar or lower activity than Pt-based catalysts. However, after high temperatures steam treatment, which modified the surface structure, the catalysts of the present disclosure had higher intrinsic activity than Pt-based catalysts. Additionally, the multicomponent alloy of the present disclosure demonstrated higher thermal stability than Pt-based catalysts that maintained their size up to 650 °C hydrothermal aging conditions.Synthesis of colloidal particles[000103] When preparing the colloidal multicomponent particles, the method needed to ensure that the decomposition / reduction of the metal precursors occurs in a predicable and controlled ways as to avoid homogeneous nucleation of individual metals. When starting from only metal salts, it resulted in the uncontrolled formation of several different particles with broad size distributions (Figure 7). Without being bound to a theory7, these results were likely because of the different decomposition temperatures of metal precursors that results in more challenging control of nucleation and growth for each element. To address this and improve control of reduction and nanocrystal formation, a seed-mediated method as described in the present disclosure was used with Pt seeds (Scheme 1). Uniform seed nanocrystals (5.2 ± 0.7 nm, Figure 8a) were prepared, isolated and then mixed with metal precursors and solvents. A reaction was performed at high temperature to achieve decomposition / reduction of metal salts, as well as alloying by metal diffusion into the Pt seeds. An initial combination of metals chosen was composed of Fe, Co, Ni and W precursors.[000104] The resulting PtFeCoNiW nanocry stals demonstrated high uniformity in their size (6.3 ± 0.8 nm), which was larger than the initial Pt seeds, thus demonstrating the deposition of metals. Energy-dispersive spectroscopy (EDS) maps of as-synthesized PtFeCoNiW nanocrystals showed the overlap of signals from all the metals, thus demonstrating the homogenous distribution of all five elements in each individual nanocrystal. EDS spectra also confirmed the presence of each element (Figure 9). The relatively lower ratio measured for Fe and W could be related to some degree of homogenous nucleation or galvanic replacement ofelements. Representative aberration-corrected TEM images of individual nanocrystals demonstrate the single-crystalline nature of the nanocrystals with a face-centered cubic (FCC) crystal structure. The calculated lattice constant was 3.8 A, which was more than 3.1% different than that of pure Pt. X-ray diffraction (XRD) analysis (Figure 10) showed three distinctive peaks (41°, 48°, and 70°, 26), and their intensity profdes matched a ty pical FCC crystal structure XRD pattern. None of these peaks matched the XRD peaks of individual elements (or their oxides). The lattice constant of the material was calculated based on XRD peaks was 3.8 A, which was in line with what was found by HR-TEM. This result demonstrated that individual and bulk characterization of the nanocrystal structure. Selected area electron diffraction (SAED) of nanocrystals was utilized to further confirm the presence of a single phase in the PtFeCoNiW nanocrystal sample (Figure 8). A representative SAED pattern collected from 77 nanocrystals (Figure 1 1) revealed an FCC crystal structure with a lattice constant of 3.8 A. No diffraction spots from different phases wer observed. Thus, all characterizations confirmed the formation of a solid solution with five elements in nanocrystals.[000105] A machine learning based materials screen was performed, the results of which are in Figure 12. The model utilized simulated phase segregation in five element particles, which could guide the synthesis of several high entropy nanoparticles (PtFeCoNiW). As described in the flow chart of Fig. 12a, the high-throughput screening starts by selecting a pool f elements including Pt / Ru and other potential metals. Atomic structures of these compositions were generated at all possible compositions with random orderings, followed by high-throughput replica-exchange molecular dynamics and Monte Carlo atom swaps (REMD / MC) simulations for all bulk compositions using the machine learning model. Next, a subset of compositions with small short range order (SRO) parameters shown in bulk REMC simulations were evaluated again by REMD / MC simulations on the corresponding surfaces. Finally, the compositions with Pt / Ru surface segregation were considered desirable and were sent to be tested experimentally.[000106] In Figs. 12b-c, the high throughput screening results of the model for Pt-containing compositions are shown. A scatter plot of the minimum average SRO vs. the standard deviation of average SRO (Fig. 12b) and correlation lot of the mean (indicate by circle color) and standard deviation (indicate by circle radius) of the average SRO from the last 3000 REMD / MC steps (Fig. 12c), for atom pairs in equimolar Pt-containing bulk compositions with four other elements chosen from 11 other metals.Versatility of synthesis method[000107] Different sizes and shapes of Pt nanocrystals were used as seed materials to investigate the effect of sizes and shapes on the synthesis. The seed materials that were used in Figure 8 have an average diameter of 5.2 ± 0.7 nm. Therefore, larger Pt nanocrystals were synthesized with an average size of 6.7 ± 0.5 nm and used as seed materials for synthesizing PtCoNiCuZn nanocrystals (Figure 13a). As a note, the Pt nanocrystal was more faceted than the 5.2 nm Pt nanocrystal. The synthesized PtCoNiCuZn nanocrystals (PtCoNiCuZn-6.7) had a size of 11.5 ± 1.6 nm with the core-shell structure (Figure 13b). EDS maps showed the presence of five elements in the individual nanocrystals. In addition, it was observed that Pt, Cu. and Zn were present in the core part, and Co and Ni were present in the shell part. The elemental distribution of PtCoNiCuZn-6.7 differed from the PtCoNiCuZn from 5 nm Pt nanocrystals (PtCoNiCuZn-5). To further understand the size and facet dependence of our synthesis, Pt cubes were used as seeds whose surfaces are mainly {100} facets. The Pt cube had a size of 10. 6 ± 1.2 nm (Figure 13c). PtCoNiCuZn nanocrystals from Pt cubes (PtCoNiCuZn- 10.6) showed a clear core-shell structure in a HAADF image, and the core part was cubic-shaped, which was the shape of their seed materials (Figure 13d). The length of the core and entire particles were 9.5 ± 1.4 and 20.4 ± 2.9 nm, respectively. The core part had a similar length to the initial seed materials, implying no significant diffusion or mixing of other elements. EDS maps were utilized to confirm the elemental distribution in the core-shell structure. The core part was mainly Pt, and the shell consisted of two layers. The shell that contacted the core was mainly Cu, and the outer shell was composed of Co, Ni, and Zn. XRD was used to understand these materials' crystal structure and identify multi-phases present in nanocrystals. The XRD spectra of PtCoNiCuZn nanocrystals from different seeds are present in Figure 13e. The PtCoNiCuZn nanocrystals from 5 nm Pt (PtCoNiCuZn-5) showed three peaks around 20 of 42.4 °, 49.37 ° and 72.4 °. The PtCoNiCuZn-6.7 also showed a distinctive FCC diffraction pattern, and its (111) peak showed 41.2 °. In the case of PtCoNiCuZn- 10.6, three distinctive FCC diffraction peaks and an additional peak around 40.0 °, 46.5 °, 67.8 °, and 43.3 ° were observed. This 43.3 ° peak matches either Cu or Zn reference peak. Other than this peak, none of the XRD peaks of individual elements matched with peaks of PtCoNiCuZn nanocrystals. In addition, the 20 of (111) peak shifted to a smaller angle with increasing size of the seed materials. The 20 of the (111) peak of Pt, PtCoNiCuZn references, and synthesized PtCoNiCuZn nanocrystals were plotted to confirm the degree of alloying(Figure 13f). A decrease in the 20 was found with increased size, which means the value gets similar to the Pt reference. This result was consistent with the EDS maps that showed the coreshell formation in larger nanocrystals. The PtCoNiCuZn-5.2 showed the highest degree of alloying with the lattice constant of 3.69 A. The PtCoNiCuZn-6.7 and -10.6 had the lattice constant of 3.79 A and 3.90 A, respectively. Although it was observed that the core of PtCoNiCuZn-10.6 nanocrystal was mainly Pt in EDS maps, its lattice constant was different from the lattice constant of Pt reference (3.92 A).[000108] A decrease in the degree of alloying with increased size can be explained in two ways. First, alloying occurs by diffusion of elements in the seed-mediated growth. Therefore, larger particles might require higher temperatures to accelerate the diffusion of atoms. In addition, the diffusion rate of atoms could depend on the facet of seed materials. The diffusion of atoms on Pt (111) may be limited. Furthermore, the facet of Pt can affect the reduction of other elements by autocatalytic reduction. A previous PtlrPdRhRu HEA nanoparticle synthesis study revealed that metal reduction was catalyzed on Pd (111) facets. Likewise, it was hypothesized that there could be differences in the reduction temperature of base metals on faceted Pt nanocrystals, which would change the compositional distnbution of final nanocrystals. These results demonstrate that the method of the present disclosre enables the controlling degree of alloying in the same combination by engineering the shape and size of seed materials. As noted above, it is difficult to control the degree of alloying in the common HEA synthesis method, which uses a high-temperature-quenching method.Catalytic Activity of the multicomponent alloy[000109] To investigate the stability and catalytic activity' of the nanocrystals, three different nanocrystals (Pt, PtFeCoNiW, PtCoNiCuZn) were deposited on y-AhOs. A Pt catalyst was prepared by depositing Pt nanocrystals that were used as seed materials. Firstly, their thermal stability was tested by aging catalysts under hydrothermal conditions (2.6 vol.% H2O and 5.0 vol.% O2 balanced with Ar) at different temperatures (600 °C and 650 °C) for 6 h. Pt, PtFeCoNiW, and PtCoNiCuZn catalysts have average diameter sizes of 4.8 ± 1.6 nm, 6.7 ± 0.9 nm. and 6.9 ± 1.1 nm, respectively, after deposition and thermal treatments that were conducted to remove surface ligands (Figure 14a). The core-shell structure with a dark core and bright shell was observed in PtFeCoNiW and PtCoNiCuZn catalysts in BF-TEM images. Thus, a core-shell structure in high entropy alloy material using in-situ TEM under oxidative conditions was supported. After 600 °C aging, the average size of Pt catalysts increased to15.3 ± 9.7 nm while PtFeCoNiW and PtCoNiCuZn catalysts maintained their initial sizes (6.7 ± 0.9 nm and 6.8 ± 1.6nm) (Figure 15). Pt catalyst average size increased to 20.6 ± 10.0 nm after 650 °C aging. PtFeCoNiW and PtCoNiCuZn catalysts had average sizes of 6.8 ± 3.3 nm and 6.8 ± 1.6 nm, respectively, after 650 °C aging (Figures 14b and c). Although PtFeCoNiW maintained its average size, the size distribution was broader than its initial distribution. Overall, PtFeCoNiW and PtCoNiCuZn catalysts showed higher thermal stability than Pt catalysts. Pt catalysts are known to be sintered by Ostwald npening by forming the volatile PtOx phase under high temperatures oxidative conditions. Many studies demonstrated that Pt can be stabilized by encapsulating it with oxide layers such as AhOs. Thus, it was hypothesized that the initial shell structure minimized the exposure of Pt atoms to air and stabilized the catalysts.[000110] The catalytic activity of these materials was also investigated. CO oxidation and CsHe oxidation were used as probe reactions because Pt catalysts are known to be active for these reactions. For CO oxidation, PtCoNiCuZn and PtFeCoNiW catalysts showed about ten times higher activity than Pt catalysts (Figure 14d).Synthesis of Colloidal Synthesis using Ru seed[000111] A nanoparticle was prepared using the same synthesis method as described using a Pt- seed above, but with a Ru-seed. The resulting RuCoNiCuZn particles are shown in Figure 16. In contrast to the PtCoNiCuZn, the elemental distribution of RuCoNiCuZn was not uniform through nanocrystals.[000112] It was found that two compositionally distinct nanoparticle species of similar size and shape arise from the RuPtFeCoNiCu synthesis seeded with Ru having a particle size of 5 nm. EDS-mapping was performed showing that one nanoparticle structure appeared to be enriched with Ru, Pt, Fe and Co, while the other observed nanoparticles containing PtFeCoNiCu with little to no Ru. This compositionally bimodal distribution of nanoparticles suggest two pathway s of nucleation. Without being bound to a theory, it is believed that the Ru-containing nanoparticles result from a seed-mediated catalytic reduction (SMCR), where as Ru-lacking nanoparticles are likely independently seeded through precursor co-reduction or possibly from nascent Pt seeds formed in the temperature ramp to 350°C. Though the sample had compositional bimodality, it is important to note that no clear core-shell structure was observed in both of these nanoparticle species. Also, the similarity in size and shape of the two differently composed nanoparticles suggest aspects of the nanoparticle formation mechanism.[000113] A machine learning based model simulator was also used for the Ru-seed embodiment of RuCoNiCuZn. The results of which are in Figure 17.[000114] Further activity comparisons between a Ru based catalyst and a Ru-seeded catalyst RuCoNiCuZn were performed using the reaction conditions and results as shown in Figure 18. [000115] A catalyst was prepared using the Ru-seed multicomponent alloy as prepared herein. The thermal and stability of the catalysts was also studied, the results of which are in Figure 19 and 20.[000116] To optimize the Ru-seed catalysts, a machine learning-based screening that was used for the Pt system described above was applied. Using this simulator, it was found that RuoFeMnW may be an ideal combination. To confirm this, a sample was prepared and an EDS maps was taken to confirm the presence of five elements in nanocrystals, (see Figure 21). In particular, Fig. 21a shows a scatter plot of the minimum average SRO vs. the standard deviation of average SRO and Fig. 21b is a correlation plot of the mean (indicated by circle color) and standard deviation (indicated by circle radius) of the average SRO from the last 3000 REMD / MC steps for atom pairs in equimolar Ru-containing bulk composition with four other elements chosen from 11 other metals.[000117] The Cowley’s short range order (SRO) parameter is commonly used for quantitative estimation of the degree of ordering in multi component alloy systems. The SRO values that were close to zero were an indicator of a well-mixed system with a random atomic distribution. The more negative the SRO value, the stronger the tendency of an atom pair to cluster together. The closer to one, the less likely it is for an atom pair to appear as first neighbors.[000118] Then, the RuCoFeMnW nanocrystals were deposited on 7-AI2O3 to test their activity for NH3 decomposition reaction. Ru nanocrystals hat were used as seeds for RuCoFeMnW nanocrystal synthesis were also deposited on the same support to use as a reference catalyst. Ru catalysts showed higher activity in light-off curves than RuCoFeMnW catalysts at temperatures low-erthan 550°C. However, the conversion of Ru catalysts decreased after 550°C while the conversion of RuCoFeMnW catalysts kept increasing with the increase of temperatures. It was found that the Ru catalyst was continuously deactivated at 550°C and 580°C. respectively. In contrast, RuCoFeMnW demonstrated high thermal stability even at 607°C.

Claims

What is claimed is:

1. A catalyst comprising: a multicomponent alloy comprising a seed and at least four elements, and wherein the seed comprises at least one platinum group metal, wherein the at least one platinum group metal comprises platinum (Pt), ruthenium (Ru), indium (Ir), palladium (Pd), or rhodium (Rh).

2. The catalyst of claim 1, wherein the at least four elements comprise iron (Fe), cobalt (Co), nickel (Ni). copper (Cu), zinc (Zn). vanadium (V), manganese (Mn), molybdenum (Mo), ruthenium (Ru), platinum (Pt), palladium (Pd), rhodium (Rh), chromium (Cr), tin (Sn), iridium (Ir), tungsten (W), indium (In), silver (Ag), zirconium (Zr), cerium (Ce), yttrium (Y), gold (Au) or a combination thereof.

3. The catalyst of claim 1, wherein the at least four elements is selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, or Cr.

4. The catalyst of claim 1, wherein the at least four elements comprise eight elements selected from Fe. Co, Ni. Cu, Zn, V. Mn, Mo, Ru. Pt, Pd, Rh, Cr, Sn, Ir, W. In, Ag. Zr. Ce, Y, or a combination thereof.

5. The catalyst of claim 1, wherein the at least four elements comprise ten elements selected from Fe. Co, Ni. Cu, Zn, V. Mn, Mo, Ru. Pt, Pd, Rh, Cr, Sn, Ir, W. In, Ag. Zr, Ce, Y, or a combination thereof.

6. The catalyst of any one of claims 1-5, wherein the seed comprises Pt or Ru.

7. The catalyst of claim 6, wherein the Pt is included in an amount of about 0. 1 wt% to about 1 wt%.

8. The catalyst of claim 6, wherein the Ru is included in an amount of about 0.1 wt% to about 1 wt%249. The catalyst of any one of claims 1-8, wherein the seed has a particle size of about 2 nm to about 50 nm.

10. The catalyst of any of the preceding claims, wherein the catalyst has a core and a shell.

11. The catalyst of claim 10, wherein the core comprises the multicomponent alloy.

12. The catalyst of any of the preceding claims, further comprise a support.

13. The catalyst of claim 12, wherein the support comprises an inorganic oxide, carbide, zirconia, alumina, or nitride material.

14. The catalyst of claim 13, wherein the support comprises AI2O3, TiCh. Ti2Ch, TisOs, Ti4C>7, TiC, ZrC, HfC, TaC, TiN, ZrN, HfN, TaN, boron carbide, boron-oxy-carbide, doped SnO2, undoped SnCh. doped carbon, undoped carbon. SiCh, undoped ZrCh, doped ZrCh or a combination thereof.

15. The catalyst of any of the preceding claims, wherein the at least four elements are equimolar.

16. The catalyst of any of the preceding claims, wherein the catalyst is prepared through colloidal synthesis.

17. The catalyst of claim 16, wherein the colloidal synthesis is prepared at a temperature from about 250°C to about 400°C.

18. The catalyst of any one of claims 1-17, wherein the catalyst comprises uniform distribution of the seed and at least four elements.

19. A method of performing a reaction comprising applying the catalyst according to any one of claims 1-18.

20. The method of claim 19, wherein the reaction comprises oxidation or reduction of carbon monoxide.

21. The method of claim 19, wherein the reaction comprises oxidation or reduction of nitric oxide.

22. The method of claim 19, wherein the reaction comprises oxidation or reduction of a hydrocarbon.

23. The method of claim 19, wherein the reaction comprises oxidation or decomposition of ammonia.

24. A method of preparing a catalyst comprising: mixing a seed and at least four elements to form a mixture, wherein the seed comprises platinum-group metals: platinum (Pt), ruthenium (Ru), iridium (Ir), palladium (Pd) or rhodium (Rh) ; heating the mixture; and applying a gas to the mixture.

25. The method of claim 24, wherein the heating occurs at a temperature of about 250°C to about 800°C.

26. The method of claim 24 or 25, wherein the gas comprises nitrogen, argon or steam.

27. The method of claim 26, wherein steam is applied for about 4 hours to about 10 hours.

28. The method of claim 24, wherein the at least four elements comprise iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), vanadium (V), manganese (Mn), molybdenum (Mo), ruthenium (Ru). platinum (Pt), palladium (Pd), rhodium (Rh). chromium (Cr). tin (Sn), iridium (Ir), tungsten (W), indium (In), silver (Ag), zirconium (Zr), cerium (Ce), yttrium (Y), or a combination thereof.

29. The method of claim 24, wherein the at least four elements is selected from Fe, Co, Ni, Cu. Zn. V, Mn. Mo, Ru, or Cr.

30. The method of claim 24, wherein the at least four elements comprise eight elements selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, W, In, Ag, Zr, Ce, Y, or a combination thereof.

31. The method of claim 24, wherein the at least four elements comprise ten elements selected from Fe, Co, Ni, Cu, Zn, V, Mn, Mo, Ru, Pt, Pd, Rh, Cr, Sn, Ir, W, In, Ag, Zr, Ce, Y, or a combination thereof.

32. The method of claim 24, wherein the seed comprises Pt or Ru.

33. The method of claim 32, wherein the Pt is included in an amount of about 0.1 wt% to about 1 wt%.

34. The method of claim 32, wherein the Ru is included in an amount of about 0.1 wt% to about 1 wt%.

35. The method of any one of claims 24-34, wherein the catalyst is stable for at least about 12 hours.

36. The method of any one of claims 24-34, wherein the seed and the at least four elements are uniform within the catalyst.

37. The method of any one of claims 24-34, wherein the catalyst has a core and a shell.27

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