Copper-containing bimetallic structures, their synthesis and applications

Abstract

This invention is entitled "Copper-Containing Bimetallic Structures, Their Synthesis, and Their Uses." Aspects of this disclosure generally relate to copper-containing bimetallic structures, methods for producing such structures, and the use of these structures as, for example, catalysts. In one aspect, the invention provides a method for forming a bimetallic structure. The method includes forming a mixture comprising a first precursor and a second precursor, the first precursor comprising copper and the second precursor comprising phosphine. The method further includes introducing a third precursor together with the mixture to form the bimetallic structure, the third precursor comprising a Group 8-10 metal, the bimetallic structure comprising copper (Cu), a Group 8-10 metal (M), phosphorus (P), and nitrogen (N), the bimetallic structure having the formula (Cu). a (M) b (P) c (N) d The molar ratio of a:b is about 1:99 to about 99:1, and the molar ratio of a:(c+d) is about 500:1 to about 1:1.

Description

Technical Field

[0001] The aspects of this disclosure generally relate to copper-containing bimetallic structures, methods for producing copper-containing bimetallic structures, and the use of bimetallic structures as, for example, catalysts. Background Technology

[0002] Various metal catalysts are used in fuel cells to improve feedstock energy conversion rates through direct electrochemical oxygen reduction and hydrogen evolution reactions. These metal catalysts typically take the form of metal nanostructures with high-index facets. The crystal properties of these facets are closely related to the shape of the catalyst particles, which subsequently affects the electrocatalytic function of the catalyst. Platinum is the most commonly used and efficient catalyst for fuel cells, and particularly for proton exchange membrane fuel cells (PEMFCs). However, the high cost of platinum limits its widespread application in fuel cells, PEMFCs, and other fields requiring large amounts of platinum.

[0003] Efforts have been made to replace expensive or relatively rare metals with abundant metals such as copper and nickel. However, the use of Cu-Ni nanoparticles, for example, in electrochemical oxygen reduction reactions, hydrogen evolution reactions, PEMFC devices, and other catalyst applications remains a challenge due to their low efficiency. Therefore, catalysts made from relatively abundant metals do not represent viable alternatives to platinum-based catalysts.

[0004] There is a need for novel bimetallic structures that can serve as high-performance alternatives to existing catalysts used, for example, in energy technologies. Summary of the Invention

[0005] The aspects of this disclosure generally relate to copper-containing bimetallic structures, methods for producing bimetallic structures, and the use of bimetallic structures as, for example, catalysts.

[0006] In one aspect, a method for forming a bimetallic structure is provided. The method includes forming a mixture comprising a first precursor and a second precursor, the first precursor comprising copper and the second precursor comprising phosphine. The method further includes introducing a third precursor together with the mixture to form the bimetallic structure, the third precursor comprising a Group 8-10 metal, the bimetallic structure comprising copper (Cu), a Group 8-10 metal (M), phosphorus (P), and nitrogen (N), the bimetallic structure having the formula (Cu). a (M) b (P) c (N) d The molar ratio of a:b is about 1:99 to about 99:1, and the molar ratio of a:(c+d) is about 500:1 to about 1:1.

[0007] In another aspect, a bimetallic structure is provided. The bimetallic structure includes: a core comprising copper and a group 8-10 metal, the core having a greater amount of copper than the group 8-10 metal; and a shell comprising copper and a group 8-10 metal, the shell having a greater amount of the group 8-10 metal than copper. The bimetallic structure further includes one or more ligands bonded to copper of the core, copper of the shell, a group 8-10 metal of the core, a group 8-10 metal of the shell, or combinations thereof, wherein at least one of the one or more ligands comprises a nitrogen-containing ligand, and at least one of the one or more ligands comprises a phosphorus-containing ligand.

[0008] In another aspect, a method for forming a conversion product is provided. The method includes introducing reactants into a bimetallic structure. The method also includes forming a conversion product, the bimetallic structure comprising copper (Cu), a group 8-10 metal (M), phosphorus (P), and nitrogen (N), the bimetallic structure having the formula (Cu). a (M) b (P) c (N) d The molar ratio of a:b is approximately 1:99 to approximately 99:1; and the molar ratio of c:d is approximately 1:100 to approximately 1:20. Attached Figure Description

[0009] The patent or application document contains at least one color drawing. A copy of the published patent or patent application with color drawings will be provided by the office upon request and payment of the necessary fees.

[0010] To enable a detailed understanding of the foregoing features of this disclosure, the disclosure, which has been briefly outlined above, can be described in more detail by reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary aspects and should not be considered as limiting its scope, as other equally effective aspects are permissible with respect to this disclosure.

[0011] Figure 1A This is an exemplary reaction diagram for forming a copper-containing bimetallic structure according to at least one aspect of this disclosure.

[0012] Figure 1B This is an exemplary reaction diagram for forming group 8-10 metal complexes according to at least one aspect of this disclosure.

[0013] Figure 2A This is a flowchart illustrating selected operations of an exemplary process for producing a copper-containing bimetallic structure according to at least one aspect of this disclosure.

[0014] Figure 2B This is a flowchart illustrating selected operations of an exemplary process for producing a copper-containing bimetallic structure according to at least one aspect of this disclosure.

[0015] Figure 3 This is an exemplary transmission electron microscope (TEM) image (scale: 200 nm) of exemplary copper-nickel (Cu-Ni) nanoparticles according to at least one aspect of this disclosure.

[0016] Figure 4A This is an exemplary scanning electron microscope (SEM) image (scale: 200 nm) of an exemplary Cu-Ni polyhedral nanoparticle according to at least one aspect of this disclosure.

[0017] Figure 4B This is an exemplary high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) image (scale: 100 nm) of exemplary Cu-Ni polyhedral nanoparticles according to at least one aspect of this disclosure.

[0018] Figure 4C This is an exemplary energy dispersive spectroscopy (EDS) image (scale: 100 nm) of the Cu portion of an exemplary Cu-Ni polyhedral nanoparticle according to at least one aspect of this disclosure.

[0019] Figure 4D This is an exemplary EDS image (scale: 100 nm) showing the Ni portion of an exemplary Cu-Ni polyhedral nanoparticle according to at least one aspect of this disclosure.

[0020] Figure 5 Exemplary energy-dispersive X-ray (EDX) spectra of exemplary Cu-Ni polyhedral nanoparticles according to at least one aspect of this disclosure.

[0021] Figure 6 This is an exemplary X-ray diffraction (XRD) pattern of exemplary Cu-Ni polyhedral nanoparticles according to at least one aspect of this disclosure.

[0022] Figure 7A This is an exemplary SEM image (scale: 300 nm) of exemplary Cu-Ni polyhedral nanoparticles formed at 200°C according to at least one aspect of this disclosure.

[0023] Figure 7B This is an exemplary SEM image (scale: 300 nm) of exemplary Cu-Ni polyhedral nanoparticles formed at 250°C according to at least one aspect of this disclosure.

[0024] Figure 7C This is an exemplary SEM image (scale: 300 nm) of exemplary Cu-Ni polyhedral nanoparticles formed at 280°C according to at least one aspect of this disclosure.

[0025] Figure 7DThis is an exemplary SEM image (scale: 300 nm) of exemplary Cu-Ni polyhedral nanoparticles formed at 300°C according to at least one aspect of this disclosure.

[0026] Figure 8 Exemplary XRD patterns of exemplary Cu-Ni polyhedral nanoparticles formed at various temperatures according to at least one aspect of this disclosure are shown.

[0027] Figure 9A Exemplary SEM images (scale: 200 nm) of exemplary Cu-Ni polyhedral nanoparticles formed using nickel nitrate (Ni(NO3)2) according to at least one aspect of this disclosure.

[0028] Figure 9B This is an exemplary SEM image (scale: 200 nm) of exemplary Cu-Ni polyhedral nanoparticles formed using nickel chloride (NiCl2) according to at least one aspect of this disclosure.

[0029] Figure 9C This is an exemplary XRD pattern of exemplary Cu-Ni polyhedral nanoparticles formed using Ni(NO3)2 according to at least one aspect of this disclosure.

[0030] Figure 9D This is an exemplary XRD pattern of exemplary Cu-Ni polyhedral nanoparticles formed using a NiCl2 precursor according to at least one aspect of this disclosure.

[0031] Figure 10A This is an exemplary SEM image (scale: 200 nm) of an exemplary Cu-Ni polyhedral nanoparticle formed using tributylphosphine according to at least one aspect of this disclosure.

[0032] Figure 10B This is an exemplary TEM image (scale: 50 nm) of exemplary Cu-Ni polyhedral nanoparticles formed using tributylphosphine according to at least one aspect of this disclosure.

[0033] Figure 10C This is an exemplary XRD pattern of exemplary Cu-Ni polyhedral nanoparticles formed using at least one aspect of this disclosure.

[0034] Figure 11A This is an exemplary SEM image (scale: 100 nm) of exemplary copper-cobalt (Cu-Co) polyhedral nanoparticles according to at least one aspect of this disclosure.

[0035] Figure 11B This is an exemplary SEM image (scale: 100 nm) of exemplary copper-iron (Cu-Fe) polyhedral nanoparticles according to at least one aspect of this disclosure.

[0036] Figure 11C These are exemplary XRD images of exemplary Cu-Co polyhedral nanoparticles according to at least one aspect of this disclosure.

[0037] Figure 11D These are exemplary XRD images of exemplary Cu-Fe polyhedral nanoparticles according to at least one aspect of this disclosure.

[0038] For ease of understanding, the same reference numerals are used where possible to denote common elements in the figures. It is conceivable that elements and features of one example may be advantageously combined in other examples without further detail. Detailed Implementation

[0039] This disclosure generally relates to copper-containing bimetallic structures, methods for producing copper-containing bimetallic structures, and the use of copper-containing bimetallic structures as, for example, catalysts. The inventors have discovered novel copper-containing bimetallic structures comprising copper and metals from Groups 8-10 of the periodic table. These bimetallic structures can be in the form of metallic polyhedral nanostructures, such as nanocrystals and nanoparticles, wherein copper and the Group 8-10 metals can be in an alloy phase.

[0040] The inventors have also discovered a method for forming copper-containing bimetallic structures. Briefly, and in some examples, the method involves reacting a copper-containing compound, a phosphorus-containing compound, and a compound containing Group 8-10 metals under conditions conducive to the formation of copper-containing bimetallic structures. The method described herein allows for control over, for example, the morphology of the bimetallic structure, its structure, the number of active surface sites, and other chemical and physical properties. Copper-containing bimetallic structures can be used as catalysts, for example, in electrochemical oxygen reduction reactions and hydrogen evolution reactions. In such applications, copper-containing bimetallic structures can be integrated into a portion of a PEMFC device.

[0041] Copper-containing bimetallic structure

[0042] This disclosure generally relates to copper-containing bimetallic structures. Copper-containing bimetallic structures can take the form of nanoparticles, microparticles, large particles, nanocrystals, microcrystals, and / or large crystals. However, other structures are contemplated. Bimetallic structures can be in the form of compositions. Bimetallic structures can take the form of homogeneous structures (such as alloy structures) and heterogeneous structures (such as core-shell structures and / or heterogeneous structures). Other structures include intermetallic structures and partial alloys. Each of these different types of bimetallic structures can have different physical properties.

[0043] Copper-containing bimetallic structures include copper (Cu) and one or more elements (e.g., metals) from Groups 8 to 10 of the periodic table, such as iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), or combinations thereof, such as Fe, Co, Ni, or combinations thereof. Copper-containing bimetallic structures may also include phosphorus atoms, nitrogen atoms, or both. Phosphorus atoms and / or nitrogen atoms may be in the form of ligands and / or chelating groups bonded to copper, Group 8-10 metals, or both copper and Group 8-10 metals. When ligands and / or chelating groups are present, they may be in the form of neutral species, monodentate species, bidentate species, and / or polydentate species.

[0044] In some respects, copper-containing bimetallic structures have the following formula:

[0045] (Cu) a (M) b (P) c (N) d ,

[0046] Where: Cu is copper, M is a group 8-10 metal, P is phosphorus, N is nitrogen, a is the amount of Cu, b is the amount of M, c is the amount of phosphorus, and d is the amount of nitrogen.

[0047] The molar ratio of a:b can be from about 1:99 to about 99:1, such as from about 10:90 to about 90:10, such as from about 20:80 to about 80:20, such as from about 30:70 to about 70:30, such as from about 40:60 to about 60:40, such as from about 45:55 to about 55:45, such as from about 48:52 to about 50:50. In some aspects, the molar ratio of a:b can be from about 20:1 to about 1:20, such as from about 10:1 to about 1:10, such as from about 5:1 to about 1:5, such as from about 3:1 to about 1:3, such as from about 2:1 to about 1:2. In at least one aspect, the molar ratio of a:b is from about 1:99 to about 20:1, such as from about 5:95 to about 10:1, such as from about 10:90 to about 1:1, such as from about 30:70 to about 40:60.

[0048] The molar ratio of a:c can be from about 1000:1 to about 100:1, such as from about 900:1 to about 200:1, such as from about 800:1 to about 300:1, such as from about 700:1 to about 400:1, such as from about 600:1 to about 500:1. In at least one aspect, the molar ratio of a:c is from about 50:1 to 1:1, such as from about 20:1 to about 3:1, such as from about 10:1 to about 5:1.

[0049] The molar ratio of a:d can be from about 500:1 to about 50:1, such as from about 450:1 to about 100:1, such as from about 400:1 to about 150:1, such as from about 350:1 to about 200:1, such as from about 300:1 to about 250:1. In at least one aspect, the molar ratio of a:d is from about 40:1 to 1:1, such as from about 20:1 to about 3:1, such as from about 10:1 to about 5:1.

[0050] The molar ratio of b:c can be from about 500:1 to about 50:1, such as from about 450:1 to about 100:1, such as from about 400:1 to about 150:1, such as from about 350:1 to about 200:1, such as from about 300:1 to about 250:1. In at least one aspect, the molar ratio of b:c is from about 40:1 to 1:1, such as from about 20:1 to about 3:1, such as from about 10:1 to about 5:1.

[0051] The molar ratio of b:d can be from about 150:1 to about 10:1, such as from about 125:1 to about 25:1, such as from about 100:1 to about 40:1, such as from about 90:1 to about 50:1, such as from about 80:1 to about 60:1, such as from about 75:1 to about 65:1. In at least one aspect, the molar ratio of b:d is from about 10:1 to 1:1, such as from about 8:1 to about 3:1, such as from about 7:1 to about 5:1.

[0052] The molar ratio of c:d can be from about 1:100 to about 1:20, such as from about 1:80 to about 1:30, or from about 1:60 to about 1:45. In at least one aspect, the molar ratio of b:d is from about 1:20 to about 1:1, such as from about 1:10 to about 1:3, or from about 1:6 to about 1:5.

[0053] The molar ratio of a:(c+d) can be from about 500:1 to about 1:1, such as from about 400:1 to about 20:1, such as from about 200:1 to about 50:1, such as from about 150:1 to about 80:1, such as from about 130:1 to about 90:1, such as from about 120:1 to about 95:1, such as from about 110:1 to about 105:1.

[0054] For copper-containing bimetallic structures, the molar ratios of a:b, a:c, a:d, b:c, b:d, c:d, and a:(c+d) were determined by transmission electron microscopy of the copper-containing bimetallic structure being analyzed.

[0055] For methods used to produce copper-containing bimetallic structures, the molar ratios of a:b, a:c, a:d, b:c, b:d, c:d, and a:(c+d) of the copper-containing bimetallic structures are determined based on the molar ratios of the starting materials used for synthesis.

[0056] The phosphorus in the bimetallic structure is derived from phosphorus-containing compounds used to synthesize copper-containing bimetallic structures. These phosphorus-containing compounds include phosphine with the following formula:

[0057] PR 1 R 2 R 3 ,

[0058] in:

[0059] R 1 R 2 and R 3 Each is independently selected from hydrogen, unsubstituted hydrocarbon group, substituted hydrocarbon group, unsubstituted aryl group, substituted aryl group, or R. 1 R 2 and / or R 3 Two or more of these groups can link together to form substituted or unsubstituted cyclic or polycyclic structures. Unsubstituted hydrocarbon groups include C1-C1 groups. 100 Unsubstituted hydrocarbon groups, such as C1-C 40 Unsubstituted hydrocarbon groups, such as C1-C 20 Unsubstituted hydrocarbon groups, such as C1-C 10 Unsubstituted hydrocarbon groups, such as C1-C6 unsubstituted hydrocarbon groups. Substituted hydrocarbon groups include C1-C6 unsubstituted hydrocarbon groups. 100 Substituted hydrocarbon groups, such as C1-C 40 Substituted hydrocarbon groups, such as C1-C 20 Substituted hydrocarbon groups, such as C1-C 10 Substituted hydrocarbon groups, such as C1-C6 substituted hydrocarbon groups. Unsubstituted aryl groups include C4-C6 substituted hydrocarbon groups. 100 Unsubstituted aryl groups, such as C4-C 40 Unsubstituted aryl groups, such as C4-C 20 Unsubstituted aryl groups, such as C4-C 10 Unsubstituted aryl group. Substituted aryl groups include C4-C. 100 Substituted aryl groups, such as C4-C 40 Substituted aryl groups, such as C4-C 20 Substituted aryl groups, such as C4-C 10 .

[0060] R 1 R 2 and R 3 Each is independently saturated or unsaturated, straight-chain or branched, cyclic or acyclic, aromatic or non-aromatic. When R 1 R 2 and / or R 3 When one or more of these components are connected together, the resulting structure can be substituted or unsubstituted, fully saturated, partially unsaturated or completely unsaturated, aromatic or non-aromatic, cyclic or polycyclic.

[0061] In at least one respect, R 1 R 2 Or R3 One or more of them independently are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, sec-pentyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl, isoheptyl, sec-heptyl, n-octyl, isooctyl, sec-octyl, n-nonyl, isonyl, sec-nonyl, n-decyl, isodel, or sec-decyl, cyclopentyl, cyclohexyl, phenyl, benzyl, their isomers or their derivatives.

[0062] In some respects, and when R 1 R 2 Or R 3 When one or more of the elements are independently substituted hydrocarbon groups or substituted aryl groups, at least one carbon atom of the substituted hydrocarbon group or substituted aryl group has been replaced by at least one heteroatom or a heteroatom-containing group, such as one or more elements in groups 13-17 of the periodic table, such as halogens (F, Cl, Br or I), O, N, Se, Te, P, As, Sb, S, B, Si, Ge, Sn, Pb, etc., such as NR*2, OR* (e.g., OH or O2H), SeR*, TeR*, PR*2, AsR*2, SbR*2, SR*, SO x (where x = 2 or 3), BR*2, SiR*3, GeR*3, SnR*3, PbR*3, etc., or at least one heteroatom of which has been inserted into a hydrocarbon or aryl group, such as halogens (Cl, Br, I, F), O, N, S, Se, Te, NR*, PR*, AsR*, SbR*, BR*, SiR*2, GeR*2, SnR*2, PbR*2, etc., where R* is independently hydrogen or a hydrocarbon group (e.g., C1-C). 10 ), or two or more R* may be linked together to form substituted or unsubstituted fully saturated, partially unsaturated, fully unsaturated structures or aromatic cyclic structures or polycyclic structures.

[0063] Examples of illustrative but non-limiting phosphorus-containing compounds include alkylphosphine and / or arylphosphine, such as trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, trioctylphosphine, tricyclohexylphosphine, diethylphosphine, dibutylphosphine, diphenylphosphine, dimethylethylphosphine, triphenylphosphine, their isomers, their derivatives, and combinations thereof.

[0064] The nitrogen in the bimetallic structure originates from nitrogen-containing compounds used to synthesize copper-containing bimetallic structures. Such nitrogen-containing compounds include, for example, primary amines, secondary amines, tertiary amines, or combinations thereof. Nitrogen-containing compounds may include unsubstituted or substituted hydrocarbon groups (as described herein) bonded to the nitrogen in the nitrogen-containing compound, wherein the unsubstituted or substituted hydrocarbon groups may be saturated or unsaturated, straight-chain or branched, cyclic or acyclic, aromatic or non-aromatic. Nitrogen-containing compounds may be alkylamines. Illustrative but non-limiting examples of nitrogen-containing compounds include oleylamine (OLA), octadecylamine (ODA), hexadecylamine (HDA), dodecylamine (DDA), tetradecylamine (TDA), their isomers, their derivatives, or combinations thereof.

[0065] In some aspects, copper-containing bimetallic structures can have an average particle size of about 5 nm to about 2000 μm, such as about 50 nm to 200 μm, such as about 50 nm to 20 μm, such as about 50 nm to 2 μm, such as about 500 nm to 2 μm. For polyhedral particles, the average particle size is the equivalent side length measured by TEM. In some examples, the average particle size can be about 5 nm or larger, such as about 10 nm to about 100 nm, such as about 15 nm to about 95 nm, 20 nm to about 90 nm, such as about 25 nm to about 85 nm, such as about 30 nm to about 80 nm, such as about 35 nm to about 75 nm, such as about 40 nm to about 70 nm, such as about 45 nm to about 65 nm, such as about 50 nm to about 60 nm, such as about 50 nm to about 60 nm, such as about 50 nm to about 55 nm, or about 55 nm to about 60 nm. In some examples, the average particle size can be from about 10 nm to about 400 nm, such as from about 25 nm to about 375 nm, such as from about 50 nm to about 350 nm, such as from about 75 nm to about 325 nm, such as from about 100 nm to about 300 nm, such as from about 125 nm to about 275 nm, such as from about 150 nm to about 250 nm, such as from about 175 nm to about 225 nm, such as from about 175 nm to about 200 nm, or from about 200 nm to about 225 nm.

[0066] Copper-containing bimetallic structures can take the form of core-shell structures, where, for example, copper and Group 8-10 metals are present in both the core and the shell. In some examples, as determined by elemental mapping using energy dispersive spectroscopy, copper may be predominantly located in the core (or center) of the bimetallic structure (e.g., grains or crystals), and the Group 8-10 metals may be predominantly distributed around (or within) the peripheral regions of the core-shell structure.

[0067] As an example, particles, such as metal particles, may include a core and a shell. The core may include copper and Group 8-10 metals, wherein the amount of copper in the core may be greater than, equal to, or less than the amount of Group 8-10 metals in the core. The shell may include copper and Group 8-10 metals, wherein the amount of Group 8-10 metals in the core may be greater than, equal to, or less than the amount of copper in the shell. The amount of copper and / or Group 8-10 metals in the core or shell can be adjusted, for example, by changing the reaction temperature. Similarly, the amount of copper and / or Group 8-10 metals in a core-shell structure can be adjusted, for example, by changing the reaction temperature. Particles may also include one or more ligands that are physically and / or chemically bound to the copper in the core, the copper in the shell, the Group 8-10 metal in the core, the Group 8-10 metal in the shell, or a combination thereof. Such ligands may include nitrogen, phosphorus, or both. Illustrative but non-limiting examples of such ligands include or are derived from the phosphorus-containing and nitrogen-containing compounds described above.

[0068] Copper-containing bimetallic structures may comprise particles and / or crystals having a desired number of facets and various three-dimensional shapes (e.g., polyhedra). The number of facets may be about 4 or more, such as about 4 to about 50 facets, about 8 to about 40 facets, about 12 to about 30 facets, or about 18 to about 20 facets. The number of facets may be a multiple of two, starting with about 4 facets, and / or a multiple of five, starting with about 5 facets. The number of facets may be one or more of 4, 8, 12, 15, 18, 20, 24, 30, 40, or 50 facets.

[0069] In some respects, the copper-containing bimetallic structure has an X-ray diffraction pattern showing peaks at {111}, {200}, {220} and / or {311}.

[0070] Methods for producing copper-containing bimetallic structures

[0071] This disclosure also relates to methods for forming copper-containing bimetallic structures, such as those described above. Figure 1A and Figure 1B Reaction diagrams 100 and 120 are shown respectively, illustrating the selected operations used to form a copper-containing bimetallic structure (such as the copper-containing bimetallic structure described above). Figure 2A This is a flowchart illustrating selected operations of an exemplary process 200 for producing a copper-containing bimetallic structure according to at least one aspect of this disclosure.

[0072] Process 200 includes forming a mixture 109 comprising a first precursor and a second precursor under first conditions at operation 210. The first precursor comprises copper, and the second precursor comprises a phosphorus-containing compound. The copper in the first precursor may be in the form of a copper complex 105.

[0073] The copper complex 105 of the first precursor can be prepared, for example, by introducing a copper source 101 together with a nitrogen-containing compound 103 under conditions 104 that effectively form the copper complex 105. The copper complex 105 can be a copper amine. The copper source 101 can include one or more ligands, such as halide ions (e.g., I₂). – ,Br – Cl – or F – ), acetylacetonate (O2C5H7) – ), hydrogen ions (H) – ), SCN – NO2 – NO3 – N3 – OH – oxalate (C2O4) 2– H2O, acetate (CH3COO) – O2 – CN – OCN – OCN – CNO – NH2 – NH 2– NC – NCS – N(CN)2 – The copper source 101 may be pyridine (py), ethylenediamine (en), 2,2'-bispyridine (bipy), PPh3, or combinations thereof. In some aspects, the copper source 101 may include copper acetate, copper halide, copper nitrate, and / or other copper species. The nitrogen-containing compound 103 may be one of the nitrogen-containing compounds described above. Examples of illustrative but non-limiting nitrogen-containing compounds 103 include OLA, ODA, HDA, DDA, TDA, or combinations thereof. The nitrogen-containing compound 103 may be used as a solvent. When necessary, solvents such as octaene, phenyl ether, benzyl ether, or combinations thereof may be used additionally or alternatively. In some examples, the molar ratio of the copper source to the nitrogen-containing compound is from about 1:1000 to about 1:1, such as from about 1:500 to about 1:1, such as from about 1:100 to about 1:1, such as from about 1:50 to about 1:1. In some respects, based on the molar ratio of the original materials used in the reaction, the molar ratio of the copper source to the nitrogen-containing compound is about 1:20 to about 1:1, such as about 1:10 to about 1:1, such as about 1:4 to about 1:1, such as about 1:2 to about 1:1.

[0074] The conditions 104 for the effective formation of the copper complex 105 (e.g., copper amine) may include a reaction temperature and a reaction time. The reaction temperature for forming the copper complex 105 may be greater than about 40°C, such as greater than about 60°C, such as greater than about 80°C, such as about 100°C to about 320°C, such as about 110°C to about 310°C, such as about 120°C to about 300°C, such as about 130°C to about 290°C, such as about 140°C to about 280°C, such as about 150°C to about 270°C, such as about 160°C to about 260°C, such as about 170°C to about 250°C, such as about 180°C to about 240°C, such as about 190°C to about 230°C, or about 200°C to about 220°C. In some aspects, the reaction temperature for forming the copper complex 105 may be about 150°C to about 250°C or about 180°C to about 240°C. Higher or lower temperatures may be used where appropriate. The reaction time for forming the copper complex 105 can be about 1 minute (min) or longer or about 24 hours or shorter, such as about 1 minute to about 12 hours, about 5 minutes to about 6 hours (h), about 10 minutes to about 5.5 hours, about 15 minutes to about 5 hours, about 30 minutes to about 4 hours, about 45 minutes to about 3 hours, or about 1 hour to about 2 hours. The reaction time for forming the copper complex 105 can be longer or shorter, depending on, for example, the desired level of conversion. Any reasonable pressure can be used during the formation of the copper complex 105.

[0075] Conditions 104 for the effective formation of copper complex 105 (e.g., copper amine) may include stirring, mixing, and / or agitation. Conditions 104 for the effective formation of copper complex 105 may optionally include the use of non-reactive gases such as N2 and / or Ar. For example, a mixture of copper source 101 and nitrogen-containing compound 103 may be placed under these or other non-reactive gases to, for example, degas the various components or otherwise remove oxygen from the reaction mixture.

[0076] In some respects, copper complex 105 may be maintained in the form of a stock solution / suspension for use in operation 210. In other respects, the reaction product containing copper complex 105 may be subjected to filtration, separation, washing, quenching, rinsing, purification and / or other suitable methods to remove unwanted components and separate copper complex 105 from other components of the reaction mixture. For example, the reaction product containing copper complex 105 (which may be in particulate form) may be centrifuged to separate copper complex 105 from the mixture. Alternatively or additionally, copper complex 105 may be washed with polar solvents (such as water, acetone, ethanol, methanol or combinations thereof) and / or nonpolar solvents (such as hexane, pentane, toluene or combinations thereof). Other solvents used for washing may include ether solvents, such as diethyl ether and tetrahydrofuran; chlorocarbon solvents, such as dichloromethane and chloroform; and ethyl acetate, dimethylformamide, acetonitrile, benzene, isopropanol, n-butanol, and n-propanol. A suitable mixture of two or more of these solvents in appropriate proportions can be used to wash, purify, or otherwise separate the copper complex 105 from other components in the reaction mixture. As an example, a solvent or solvent mixture can be added to the copper complex 105 and the resulting mixture can be centrifuged. The supernatant can be discarded, and the remaining particles can be dispersed in a suitable solvent or solvent mixture. The resulting particles and solvent can be centrifuged to obtain the copper complex 105. In these and other respects, the particles containing the copper complex 105 can be redissolved or resuspended in a nitrogen-containing compound such as those described above.

[0077] The second precursor of operation 210 includes phosphorus-containing compound 107. Phosphorus-containing compound 107 may be one or more of the phosphorus-containing compounds described above.

[0078] The first conditions for operation 210 may include operating temperature and duration. Figure 1AIn this context, the first condition is indicated by the number 108. The operating temperature of operation 210 can be set to about 400°C or lower, such as about 50°C to about 400°C, about 75°C to about 375°C, about 100°C to about 350°C, about 125°C to about 325°C, about 150°C to about 300°C, about 175°C to about 275°C, about 200°C to about 250°C, or about 200°C to about 225°C. In some aspects, the operating temperature of operation 210 can be set to a temperature of about 100°C to about 150°C or about 180°C to about 320°C. Higher or lower temperatures may be used where appropriate. The time for forming the mixture of operation 210 (e.g., the first condition 108) can be about 1 minute or longer or about 24 hours or shorter, such as about 5 minutes to about 6 hours, or about 10 minutes to about 1 hour, although the intended time period may be longer or shorter. Operation 210 may include stirring, mixing, and / or agitating the mixture to ensure, for example, homogeneity of the mixture. Non-reactive gases (e.g., N2 and / or Ar) may be used to perform operation 210 to, for example, remove or substantially remove oxygen from the mixing environment. A suitable operating pressure may be used for operation 210.

[0079] Additionally, the molar ratio of the first precursor (e.g., copper complex 105) to the second precursor (e.g., phosphorus-containing compound 107) can be adjusted as needed. In some examples, based on the molar ratio of the initial materials used in the reaction, the molar ratio of copper complex 105 to phosphorus-containing compound 107 is about 50:1 to about 1:100, such as about 20:1 to about 1:50, such as about 10:1 to about 1:10. In some aspects, based on the molar ratio of the initial materials used in the reaction, the molar ratio of copper complex 105 to phosphorus-containing compound 107 is about 5:1 to about 1:5, such as about 3:1 to about 1:3, such as about 1:1 to about 1:2.

[0080] In some respects, and prior to introducing the first precursor together with the second precursor, the second precursor may be mixed with a solvent. The solvent may be a nitrogen-containing compound or include nitrogen-containing compounds, such as those described above. Alternatively, other suitable solvents may be used. The solvent and the second precursor, for example, phosphorus-containing compound 107, may be heated under a non-reactive gas (e.g., N2 and / or Ar) at a temperature of about 50°C or higher to about 400°C or lower, such as about 75°C to about 375°C, such as about 100°C to about 350°C, such as about 125°C to about 325°C, such as about 150°C to about 300°C, such as about 175°C to about 275°C, such as about 200°C to about 250°C, such as about 200°C to about 225°C, for a suitable time, such as about 24 h or less, such as about 12 h or less, such as about 5 h or less, such as about 1 h or less, such as about 30 min or less, such as about 10 min or less, and under suitable pressure. In these and other respects, the first precursor is then added to the second precursor and optionally the solvent. The resulting mixture can then be cooled to those temperatures described in the first condition above, such as about 50°C to about 400°C, about 75°C to about 375°C, about 100°C to about 350°C, about 125°C to about 325°C, about 150°C to about 300°C, about 175°C to about 275°C, about 200°C to about 250°C, or about 200°C to about 225°C, for a suitable period of time (as described above), under suitable pressure and optionally in a non-reactive gas (e.g., N2 and / or Ar).

[0081] Process 200 further includes introducing a third precursor together with mixture 109 under second conditions at operation 220 to form a bimetallic structure 113. The third precursor comprises a group 8-10 metal complex 111. The bimetallic structure 113 formed in operation 220 has the formula (Cu) as described above. a (M) b (P) c (N) d The copper-containing bimetallic structure. The chemical and physical properties of bimetallic structure 113 were also described above. Figure 1A In the middle, the second condition is indicated by the numbers 112 / 114.

[0082] For operation 220, the amount of the Group 8-10 metal complex 111 of the third precursor may be adjusted relative to one or more components of the mixture formed in operation 210 (e.g., copper complex 105 and phosphorus-containing compound 107). For example, based on the molar ratio of the initial materials used in the reaction, the molar ratio of the Group 8-10 metal complex 111 to the phosphorus-containing compound 107 may be from about 1:500 to about 1:50, such as from about 1:250 to about 1:70, such as from about 1:120 to about 1:100. In some aspects, based on the molar ratio of the initial materials used in the reaction, the molar ratio of the Group 8-10 metal complex 111 to the phosphorus-containing compound 107 may be from about 1:50 to about 1:1, such as from about 1:20 to about 1:5, such as from about 1:10 to about 1:8.

[0083] Alternatively or concurrently, based on the molar ratio of the initial materials used in the reaction, the molar ratio of Group 8-10 metal complex 111 to copper complex 105 can be from about 100:1 to about 1:10, such as from about 80:1 to about 1:20, or from about 50:1 to about 1:30. In some aspects, based on the molar ratio of the initial materials used in the reaction, the molar ratio of Group 8-10 metal complex 111 to copper complex 105 can be from about 1:1 to about 1:10, such as from about 1:2 to about 1:7, or from about 1:3 to about 1:4.

[0084] When needed, solvents such as octadecene, benzyl ether, phenyl ether, or combinations thereof can be used in operation 220. In some aspects, a third precursor comprising a group 8-10 metal complex 111 is introduced as a solution / suspension in the solvent into mixture 109. For example, nitrogen-containing compounds, such as those described above, can be used as solvents.

[0085] like Figure 1B As shown, the Group 8-10 metal complex 111 of the third precursor can be formed by introducing a Group 8-10 metal source 121 and a nitrogen-containing compound 123 under conditions 122 that are conducive to the formation of the Group 8-10 metal complex 111. The nitrogen-containing compound 123 may be the same as or different from the nitrogen-containing compound 103. The Group 8-10 metal source 121 includes metals from Group 8-10 of the periodic table, such as Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, or combinations thereof, such as Fe, Co, Ni, or combinations thereof. The Group 8-10 metal source 121 may also include one or more ligands, such as halide ions (e.g., I...). – ,Br – Cl – or F – ), acetylacetonate (O2C5H7) – ), hydrogen ions (H) – ), SCN – NO2 – NO3 –N3 – OH – oxalate (C2O4) 2– H2O, acetate (CH3COO) – O2 – CN – OCN – OCN – CNO – NH2 – NH 2– NC – NCS – N(CN)2 – Pyridine (py), ethylenediamine (en), 2,2'-bispyridine (bipy), PPh3, or combinations thereof. In some aspects, Group 8-10 metal source 121 includes metal acetates, metal acetylacetonates, metal halides, metal nitrates, and / or other Group 8-10 metal species. Illustrative but non-limiting examples of Group 8-10 metal source 121 include nickel acetylacetonate (II), nickel nitrate (II), nickel chloride (II), cobalt acetylacetonate (II), iron acetylacetonate (II), and combinations thereof.

[0086] Condition 122 for the effective formation of the group 8-10 metal complex 111 (e.g., group 8-10 metal amine) of the third precursor may include similar conditions for the formation of the copper complex 105 described above in relation to condition 104. For example, the Group 8-10 metal source 121 and the nitrogen-containing compound 123 may be mixed, stirred, and / or agitated at temperatures greater than about 40°C, such as greater than about 60°C, such as about 80°C to about 340°C, such as about 90°C to about 330°C, such as about 100°C to about 320°C, such as about 110°C to about 310°C, such as about 120°C to about 300°C, such as about 130°C to about 290°C, such as about 140°C to about 280°C, such as about 150°C to about 270°C, such as about 160°C to about 260°C, such as about 170°C to about 250°C, such as about 180°C to about 240°C, such as about 190°C to about 230°C, such as about 200°C to about 220°C. In some aspects, the reaction temperature for forming the Group 8-10 metal complex 111 may be about 150°C to about 250°C or about 180°C to about 240°C. Higher or lower temperatures may be used where appropriate. The reaction time for forming the Group 8-10 metal complex 111 may be about 1 min or longer or about 24 h or less, such as about 5 min to about 6 h, about 10 min to about 5.5 h, about 15 min to about 5 h, about 30 min to about 4 h, about 45 min to about 3 h, or about 1 h to about 2 h. The reaction time for forming the Group 8-10 metal complex 111 may depend more or less on, for example, the desired level of conversion. Any reasonable operating pressure may be used during the formation of the Group 8-10 metal complex 111. Conditions 122 effective for the Group 8-10 metal complex 111 may optionally include the use of a non-reactive gas, for example, N2 and / or Ar. For example, a mixture of the Group 8-10 metal source 121 and the nitrogen-containing compound 123 may be placed under these or other non-reactive gases to, for example, degas the various components or otherwise remove oxygen from the reaction mixture.

[0087] The second condition in operation 220 may include Figure 1A The introduction conditions 112 and reaction conditions 114 are specified. Introduction condition 112 refers to the conditions under which the third precursor containing group 8-10 metal complex 111 is introduced into the mixture 109 comprising copper complex 105, phosphorus-containing compound 107, and optionally a solvent by means of, for example, injection, addition, or otherwise incorporation of the third precursor with the mixture 109. Reaction condition 114 refers to the conditions under which one or more components of the mixture 109 react with the third precursor containing group 8-10 metal complex 111. Introduction condition 112 and reaction condition 114 may be the same or different.

[0088] Introduction condition 112 includes introduction temperature. The introduction temperature or injection temperature of operation 220 may be about 400°C or lower, such as about 50°C to about 400°C, about 75°C to about 375°C, about 80°C to about 340°C, about 90°C to about 330°C, about 100°C to about 320°C, about 110°C to about 310°C, about 120°C to about 300°C, about 130°C to about 290°C, about 140°C to about 280°C, about 150°C to about 270°C, about 160°C to about 260°C, about 170°C to about 250°C, about 180°C to about 240°C, about 190°C to about 230°C, or about 200°C to about 220°C. In some respects, the inlet or injection temperature of operation 220 can be from about 80°C to about 320°C, such as from about 80°C to about 150°C or from about 180°C to about 320°C, such as from about 200°C to about 300°C. Higher or lower inlet / injection temperatures may be used where appropriate.

[0089] The resulting mixture containing copper complex 105, phosphorus-containing compound 107, group 8-10 metal complex 111, and optional solvent may be stirred, mixed, or otherwise agitated at the introduced temperature for a period of about 1 min or longer or about 24 h or shorter, such as about 1 min to about 12 h, about 5 min to about 6 h, about 10 min to about 3 h, or about 15 min to about 1 h. The introduction conditions 112 of operation 220 may optionally include the introduction of N2, Ar, and / or other non-reactive gases before, during, and / or after the introduction of the third precursor containing group 8-10 metal complex 111 into mixture 109.

[0090] After introducing Group 8-10 metal complex 111 into mixture 109, one or more components of the resulting mixture react under reaction conditions 114 to form a bimetallic structure 113. Here, the reaction conditions 114 of operation 220 may include heating a mixture containing a copper complex 105, a phosphorus-containing compound 107, a group 8-10 metal complex 111 and an optional solvent at a reaction temperature of about 400°C or lower, such as about 50°C to about 400°C, such as about 75°C to about 375°C, such as about 80°C to about 340°C, such as about 90°C to about 330°C, such as about 100°C to about 320°C, such as about 110°C to about 310°C, such as about 120°C to about 300°C, such as about 130°C to about 290°C, such as about 140°C to about 280°C, such as about 150°C to about 270°C, such as about 160°C to about 260°C, such as about 170°C to about 250°C, such as about 180°C to about 240°C, such as about 190°C to about 230°C, such as about 200°C to about 220°C. In some aspects, the reaction temperature of reaction condition 114 can be from about 80°C to about 320°C, such as from about 80°C to about 150°C or from about 180°C to about 320°C, such as from about 200°C to about 300°C. Higher or lower temperatures may be used where appropriate. The reaction condition 114 of operation 220 may include a time of about 1 minute or longer or about 24 hours or shorter, such as from about 1 minute to about 12 hours, from about 5 minutes to about 3 hours, from about 10 minutes to about 1 hour. Higher or lower temperatures and / or longer or shorter time periods may be used where appropriate. Stirring, mixing and / or agitation may be performed to ensure, for example, homogeneity. The reaction condition 114 of operation 220 may include the introduction of N2, Ar and / or other non-reactive gases before, during and / or after the reaction of one or more components.

[0091] In some examples, reaction condition 114 includes an operating temperature that is higher than, less than, or equal to the operating temperature introduced by condition 112.

[0092] After a suitable period of time, the reaction product mixture containing the bimetallic structure 113 formed during operation 220 can be filtered, separated, washed, quenched, purified, and / or otherwise suitably processed to remove unwanted components and separate the bimetallic structure 113 from the other components of the reaction product mixture. For example, the reaction product mixture containing the bimetallic structure 113 can be centrifuged to separate the bimetallic structure 113 (which may be in particulate form) from the reaction product mixture. Alternatively or additionally, the bimetallic structure 113 can be washed with polar solvents (such as water, acetone, ethanol, methanol, or combinations thereof) and / or nonpolar solvents (such as hexane, pentane, toluene, or combinations thereof). Other solvents used for washing may include ether solvents, such as diethyl ether and tetrahydrofuran; chlorocarbon solvents, such as dichloromethane and chloroform; and ethyl acetate, dimethylformamide, acetonitrile, benzene, isopropanol, n-butanol, and n-propanol. Suitable mixtures of two or more of these solvents in appropriate proportions can be used to wash, purify the bimetallic structure 113, or otherwise separate the bimetallic structure from the other components of the reaction product mixture. As an example, a solvent or solvent mixture can be added to the bimetallic structure 113 and the resulting mixture can be centrifuged. The supernatant can be discarded, and the remaining particles can be dispersed in a suitable solvent or solvent mixture. The resulting particles and solvent can be centrifuged to obtain the bimetallic structure 113.

[0093] As a non-limiting example of operation 220, alkylphosphine, with or without a nitrogen-containing compound (such as OLA), can be degassed using a non-reactive gas during stirring. The alkylphosphine, with or without a nitrogen-containing compound, can be heated to a temperature of approximately 275°C to approximately 350°C. A copper amine is then added to the alkylphosphine and stirred. The resulting mixture containing the copper amine and the alkylphosphine (e.g., mixture 109) is then set to introductory conditions 112, such as an introductory temperature of approximately 100°C to approximately 140°C, stirred for a suitable time at a suitable pressure, with or without a non-reactive gas. A third precursor, comprising a group 8-10 metal amine with or without a nitrogen-containing compound, is then added to the mixture at this introductory temperature, and stirred for a suitable time at a suitable pressure, with or without a non-reactive gas, under introductory conditions 112. At a selected time point, the mixture of the group 8-10 metal amine, the alkylphosphine, and the copper amine is placed under reaction conditions 114. Reaction conditions 114 can be the same as or different from introductory conditions 112. In this example, reaction conditions 114 involve heating a mixture of group 8-10 metal amines, alkylphosphines, copper amines, and optionally a nitrogen-containing compound (as a solvent) at a temperature of about 225°C to about 275°C under suitable pressure and in the presence or absence of non-reactive gases to form a bimetallic structure 113. The bimetallic structure 113 can then be subjected to filtration, separation, washing, quenching, rinsing, purification, and / or other suitable methods to remove unwanted components and / or isolate the bimetallic structure 113 from other components of the reaction mixture.

[0094] Figure 2B This is a flowchart illustrating selected operations of an exemplary process 250 for producing a copper-containing bimetallic structure according to at least one aspect of this disclosure. Process 250 includes forming a mixture 109 comprising a copper complex 105 and a phosphorus-containing compound 107 under first conditions at operation 260. (The above relates to...) Figure 2A Process 200 describes a copper complex 105, a phosphorus-containing compound, a mixture 109, and first operating conditions 260. Process 250 further includes introducing a group 8-10 metal complex 111 with the mixture 109 at operation 270 to form a bimetallic structure 113. The formed bimetallic structure 113 may have the formula (Cu) as described above. a (M) b (P) c (N) d The text describes a copper-containing bimetallic structure. The chemical and physical properties of bimetallic structure 113 are also described above. The text above is about... Figure 2A Process 200 describes the Group 8-10 metal complex 111, mixture 109, the formed bimetallic structure 113, and the second conditions of operation 270.

[0095] The method for forming copper-containing bimetallic structures is efficient and utilizes low-cost materials. As shown in this paper, copper-containing bimetallic structures can be synthesized in a single operation (and in a single reactor) from copper complexes, phosphorus-containing compounds, and group 8-10 metal complexes.

[0096] Applications of copper bimetallic structures

[0097] This disclosure also relates to the uses of the copper-containing bimetallic structures described herein. For example, the copper-containing bimetallic structures described herein can be used as catalysts for a variety of reactions, such as the electrochemical oxygen reduction reaction and the hydrogen evolution reaction. The copper-containing bimetallic structures prepared by the aspects described herein have a large number of active sites for catalyzing the desired reactions, which increase the activity and atom economy of these structures compared to conventional structures.

[0098] In some examples, methods for using copper-containing bimetallic structures may include constructing a copper-containing bimetallic structure (e.g., having the formula (Cu)). a (M) b (P) c (N) d Those copper-containing bimetallic structures) are introduced into starting materials and / or reactants to form products. For example, a method for converting water into conversion products may include introducing a copper-containing bimetallic structure into water and obtaining reaction products, such as H2, O2, and combinations thereof.

[0099] In another example, a method for converting oxygen into a conversion product may include introducing a copper-containing bimetallic structure into O2 to obtain the reaction product. The reaction product of the oxygen reduction reaction depends on, for example, the electrolyte medium. For instance, when reduction is carried out in an acidic aqueous solution, the product includes hydrogen peroxide, water, or both. In an alkaline aqueous solution, the product includes hydroxide ions (OH-). - ), HO2 - Or both. In non-aqueous, aprotic solvents, the products include O2. – O2 2– Or both.

[0100] In various applications, the copper-containing bimetallic structure described herein can be integrated into a portion of a PEMFC device, such as the cathode of a PEMFC device. PEMFC devices can be used as power sources in electric vehicles, as well as portable and stationary devices.

[0101] The following embodiments are provided to provide those skilled in the art with a complete disclosure and description of how to prepare and use various aspects of this disclosure, and are not intended to limit the scope of the aspects of this disclosure. Furthermore, while this disclosure relates to “nanoparticles,” it should be understood that this disclosure is applicable to particles of larger sizes (e.g., “microparticles” and “large particles”). Similarly, while this disclosure relates to nanocrystals, it should be understood that this disclosure is applicable to crystals of larger sizes, such as microcrystals and macrocrystals. Efforts have been made to ensure the accuracy of the figures used (e.g., quantity, size, etc.), but some experimental errors and biases should be taken into account.

[0102] Example

[0103] Copper chloride (CuCl, 99.0%), tributylphosphine (TBP, 99%), trioctylphosphine (TOP, 97%), oleylamine (OLA, 70%), nickel acetylacetonate (Ni(acac)2), nickel nitrate (Ni(NO3)2), nickel chloride (NiCl2), cobalt acetylacetonate (Co(acac)2), iron(II) acetylacetonate (Fe(acac)2), toluene (99.9%), acetone (99%), chloroform (99.9%), and 1-octaene (ODE, 98%) were purchased from Sigma-Aldrich. Tetradecylamine (TDA, >96%) was purchased from TCI (USA). Hexane (99%), methanol (99%), and ethanol (200% standard alcohol) were purchased from Fisher Chemicals. All chemicals were used as is.

[0104] QUANTA uses a field emitter as an electron source. TM SEM images were captured using a FEG 650 scanning electron microscope (from FEITecnai). QUANTA was also used. TM Surface morphology was studied using a FEG 650 scanning electron microscope. Transmission electron microscopy (TEM) images were captured using a FEI Tecnai 20 microscope with an accelerating voltage of 200 kV.

[0105] X-ray diffraction (XRD) patterns were obtained using a Bruker D8 Advance X-ray diffractometer with Cu Kα radiation, operating at a tube voltage of 40 kV and a current of 40 mA. Energy-dispersive X-ray spectroscopy (EDS) images and high-angle annular dark-field (HAADF) images were obtained using a Titan X-ray diffractometer with probe correction at an accelerating voltage of 300 kV. 3TM Collect at 80-300 s / TEM.

[0106] Example 1: Synthesis of an exemplary metal amine

[0107] Example 1A. Synthesis of Copper-TDA (Cu-TDA)In an Ar or N2 environment, copper chloride (I) (approximately 100 mg, approximately 1 mmol), TDA (approximately 240 mg), and ODE (approximately 2 mL) are mixed in a flask to form a solution / suspension. After degassing for approximately 20 minutes, the solution / suspension is heated to approximately 200°C under Ar and / or N2. After maintaining the solution / suspension at this temperature for approximately 10 minutes, the solution / suspension is cooled to room temperature. This Cu-TDA solution / suspension is used as a Cu-TDA stock solution.

[0108] Example 1B. Synthesis of Nickel-OLA (Ni-OLA) In an Ar or N2 environment, Ni(acac)₂ (approximately 128 mg, approximately 0.5 mmol) and OLA (approximately 4 mL) are mixed in a flask to form a solution / suspension. The solution / suspension is then heated at approximately 50–150 °C and shaken for approximately 5 minutes. The solution / suspension is then cooled to approximately room temperature. This Ni-OLA solution / suspension is used as a Ni-OLA stock solution.

[0109] Example 2: Synthesis of Exemplary Polyhedral Nanoparticles

[0110] Example 2A. Synthesis of Cu-Ni polyhedral nanoparticles Add OLA (70%, about 6 mL) to a 50 mL three-necked flask, where oxygen is purged with Ar or N2 for about 20 min. After degassing, inject TOP (about 1 mL) into the three-necked flask under Ar or N2. After about 20 min of degassing, rapidly heat the mixture to about 300 °C under Ar and / or N2. Next, rapidly inject about 2 mL of Cu-TDA stock solution (Example 1A) into the three-necked flask, and the reaction solution turns red. Then cool the reaction solution to about 120 °C, and then inject about 4 mL of Ni-OLA stock solution (Example 1B), maintaining the reaction solution at about 120 °C. After about 1 hour at about 120 °C, heat the reaction solution to about 250 °C. After about 5 minutes at about 250 °C, cool the reaction solution to about room temperature and add about 5 mL of hexane (or other hydrophobic solvents such as toluene and chloroform) and about 5 mL of ethanol into the three-necked flask. The obtained Cu-Ni polyhedral nanoparticles were separated by centrifugation at approximately 4000 rpm for about 5 minutes, and the supernatant was discarded. Hexane (approximately 10 mL) was then added to the granules, and the mixture was centrifuged at approximately 4000 rpm for about 5 minutes. Another amount of hexane (approximately 10 mL) was added to the granules, and the mixture was centrifuged at approximately 4000 rpm for about 5 minutes. Two washes helped remove unreacted precursors and other materials. The Cu-Ni polyhedral nanoparticles were stored in a hydrophobic solvent (e.g., hexane, toluene, and / or chloroform) prior to characterization. The Cu-Ni polyhedral nanoparticles prepared according to this procedure are referred to as Example 2A.

[0111] Synthesis of Cu-Ni polyhedral nanoparticles in Examples 2B-2E: For ExamplesExamples 2B-2E were performed following a procedure similar to that of Example 2A. However, for Examples 2B, 2C, 2D, and 2E, the Ni precursor was implanted at temperatures of 200°C, 250°C, 280°C, or 300°C, respectively. For Example 2B, after implantation, the mixture was stirred at 200°C for approximately 1 hour, and then the temperature was increased to a reaction temperature of 250°C. After approximately 5 minutes, the reaction solution was cooled to approximately room temperature, at which point a washing procedure with hexane and ethanol and centrifugation were performed as described above. For Examples 2C, 2D, and 2E, the implantation temperature was equal to the reaction temperature, and the mixture was stirred at this temperature for approximately 1 hour. After approximately 5 minutes, the reaction solution was cooled to approximately room temperature, at which point a washing procedure with hexane and ethanol and centrifugation were performed as described above.

[0112] Example 2: Synthesis of F-2G.Cu-Ni polyhedral nanoparticles: For example... Examples 2F and 2G were performed according to a procedure similar to that of Example 2A. However, different Ni stock solutions were used to form the nanoparticles. Here, the Ni stock solution was prepared by using nickel nitrate (Example 2F) or nickel chloride (Example 2G) instead of nickel acetylacetonate in Example 1B. The nickel nitrate and nickel chloride were then used to prepare the Ni-OLA stock solution using a procedure similar to that described for Example 1B.

[0113] Example 2H. Synthesis of Cu-Ni polyhedral nanoparticles using tributylphosphine In this embodiment, a procedure similar to that of Example 2A is followed. However, tributylphosphine (TBP) is used instead of trioctylphosphine.

[0114] Example 2I. Synthesis of Cu-Co polyhedral nanoparticles Cu-Co polyhedral nanoparticles were synthesized using a procedure similar to that described in Example 2A, but with Co-OLA precursors used instead of Ni-OLA precursors. Co-OLA precursors were formed using a procedure similar to that described in Example 1B, but with Co(acac)₂ used instead of Ni(acac)₂ as the metal source.

[0115] Example 2. Synthesis of Cu-Fe polyhedral nanoparticles Cu-Fe polyhedral nanoparticles were synthesized using a procedure similar to that described in Example 2A, but with Fe-OLA precursor used instead of Ni-OLA precursor. The Fe-OLA precursor was formed using a procedure similar to that described in Example 1B, but with Fe(acac)₂ used instead of Ni(acac)₂ as the metal source.

[0116] Figure 3 This is an exemplary TEM image of exemplary Cu-Ni polyhedral nanoparticles prepared according to Example 2A described above. In this embodiment, the Ni precursor was implanted at a temperature of approximately 120°C. The TEM image indicates that the Cu-Ni polyhedral nanoparticles are homogeneous. Figure 4AThe SEM images indicate that over 90% of the nanoparticles formed under the conditions of Example 2A have a dodecahedral structure. HAADF-STEM images ( Figure 4B This further indicates that most of the nanoparticles in Example 2A adopt a polyhedral morphology. HAADF-STEM images also show that the average particle size of the Cu-Ni polyhedral nanoparticles is approximately 68 nm. The core-shell structure of the nanoparticles (Example 2A) is composed of... Figure 4C and Figure 4D EDX mapping images confirm that Cu is primarily located within the interior of each nanoparticle structure. Figure 4C Ni is mainly distributed in the outer region of each nanoparticle structure. Figure 4D ).

[0117] Figure 5 The EDX spectrum of Cu-Ni polyhedral nanoparticles is shown (Example 2A). The EDX spectrum indicates that the molar ratio of Cu to Ni is approximately 40:60. Figure 6 These are the XRD patterns of these Cu-Ni polyhedral nanoparticles. The XRD patterns show that the Cu-Ni polyhedral nanoparticles have a face-centered cubic structure, as indicated by the {111}, {200}, and {220} diffraction peaks. Furthermore, no oxidation peaks were observed in the XRD patterns, indicating that the Cu-Ni polyhedral nanoparticles are stable in solution.

[0118] Cu-Ni polyhedral nanoparticles were also synthesized using different implantation temperatures (approximately 200°C (Example 2B), approximately 250°C (Example 2C), approximately 280°C (Example 2D), and approximately 300°C (Example 2E)). For these examples, the Ni precursor from Example 1B was implanted at these different implantation temperatures. SEM images of the Cu-Ni polyhedral nanoparticles from Examples 2B, 2C, 2D, and 2E are shown in [reference needed]. Figure 7A , Figure 7B , Figure 7C and Figure 7D These SEM images indicate that over 90% of the nanoparticles formed under these conditions have a dodecahedral structure. Figure 8 The corresponding XRD patterns of Examples 2B-2E are shown in the figure. These XRD patterns confirm that the Cu-Ni polyhedral nanoparticles are in the alloy phase because the typical diffraction peaks at {111}, {200}, and {220} are located between the diffraction peaks of pure Cu and pure Ni.

[0119] Cu-Ni polyhedral nanoparticles were also synthesized using nickel nitrate (Example 2F) or nickel chloride (Example 2G) instead of nickel acetylacetone as described above. SEM images of these Cu-Ni polyhedral nanoparticles are shown below. Figure 9A (Example 2F) and Figure 9BIn (Example 2G). Figure 9A and Figure 9B The SEM images indicate that approximately 90% or more of the nanoparticles formed under these conditions have a dodecahedral structure. The corresponding XRD patterns for Examples 2F and 2G are shown in [images / descriptions]. Figure 9C and Figure 9D These XRD patterns confirm that the Cu-Ni polyhedral nanoparticles are in the alloy phase, as the typical diffraction peaks at {111}, {200}, and {220} lie between the diffraction peaks of pure Cu and pure Ni.

[0120] Cu-Ni polyhedral nanoparticles were also synthesized using tributylphosphine (Example 2H) instead of trioctylphosphine (Example 2A). For this experiment, other synthesis conditions remained unchanged. When trioctylphosphine was used as the ligand (Example 2A), the average particle size of the Cu-Ni polyhedral nanoparticles varied from approximately 40 nm to approximately 100 nm. When tributylphosphine was used as the ligand (Example 2H), as... Figure 10A and Figure 10B As shown, the average particle size of the Cu-Ni polyhedral nanoparticles was reduced to approximately 15 nm. While not wishing to be bound by theory, the particles of Example 2H are likely to be smaller in size because tributylphosphine has a stronger coordination ability with copper and nickel atoms than trioctylphosphine, which could reduce the nucleation and / or growth rate of the Cu-Ni polyhedral nanoparticles. These results indicate that the size of the Cu-Ni polyhedral nanoparticles can be controlled. The XRD pattern of the Cu-Ni polyhedral nanoparticles (Example 2H) is shown in... Figure 10C As shown in the figure. The XRD pattern confirms that the Cu-Ni polyhedral nanoparticles are in the alloy phase, because the typical diffraction peaks at {111}, {200} and {220} are located between the diffraction peaks of pure Cu and pure Ni.

[0121] Cu-Co polyhedral nanoparticles (Example 2I) and Cu-Fe polyhedral nanoparticles (Example 2J) were also synthesized as described above. SEM images of the Cu-Co and Cu-Fe polyhedral nanoparticles are shown below. Figure 11A and Figure 11B The XRD patterns of Cu-Co polyhedral nanoparticles and Cu-Fe polyhedral nanoparticles are shown in the figure. Figure 11C and Figure 11D SEM images indicate the formation of Cu-Co and Cu-Fe polyhedral nanoparticles. The broad size distribution of both Cu-Co and Cu-Fe polyhedral nanoparticles can be attributed to the easier oxidation of cobalt and iron precursors compared to nickel precursors. These results confirm that various metals can be used to form polyhedral nanoparticles.

[0122] Overall, the results demonstrate that polyhedral nanoparticles comprising copper and Group 8-10 metals can be synthesized using various precursor compounds and metal sources (such as phosphorus- and nitrogen-containing compounds, copper sources, and Group 8-10 metal sources). EDS images and XRD patterns indicate that the synthesized nanoparticles can be in the form of polyhedral nanoparticles, with the metals within an alloy phase. TEM and SEM images show that the size of the polyhedral nanoparticles can be controlled using, for example, various reaction conditions.

[0123] This paper describes copper-containing bimetallic structures and methods for producing them. The copper-containing bimetallic structures can take the form of polyhedral nanostructures, such as polyhedral nanoparticles. The metal (e.g., Cu and Ni) of the polyhedral nanoparticles is in an alloy phase. The methods described herein enable, for example, control of the average particle size of the polyhedral nanoparticles. The described methods are effective and represent a cost-effective method for manufacturing catalysts for, for example, fuel cells.

[0124] Aspect List

[0125] Among other things, this disclosure also provides for aspects in which each may be considered to optionally include any other aspects:

[0126] Clause 1. A method for forming a bimetallic structure, the method comprising:

[0127] A mixture comprising a first precursor and a second precursor is formed, wherein the first precursor comprises copper and the second precursor comprises phosphine;

[0128] A third precursor is introduced together with the mixture to form the bimetallic structure, the third precursor comprising a Group 8-10 metal, and the bimetallic structure comprising copper (Cu), a Group 8-10 metal (M), phosphorus (P), and nitrogen (N), the bimetallic structure having the formula...

[0129] (Cu) a (M) b (P) c (N) d ,

[0130] in:

[0131] The molar ratio of a:b is approximately 1:99 to approximately 99:1; and

[0132] The molar ratio of a:(c+d) is approximately 500:1 to approximately 1:1.

[0133] Clause 2. The method according to Clause 1, wherein the third precursor is introduced at a first temperature of about 100°C to about 320°C.

[0134] Clause 3. The method according to Clause 2, wherein the third precursor and the mixture react at a second temperature of about 100°C to about 320°C, the second temperature being the same as or different from the first temperature.

[0135] Clause 4. The method according to any one of Clauses 1 to 3, wherein the phosphine is an alkylphosphine, an arylphosphine, or a combination thereof.

[0136] Clause 5. The method according to any one of Clauses 1 to 4, wherein the phosphine comprises trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, trioctylphosphine, tricyclohexylphosphine, diethylphosphine, dibutylphosphine, diphenylphosphine, dimethylethylphosphine, triphenylphosphine, isomers thereof, derivatives thereof, and combinations thereof.

[0137] Clause 6. The method according to any one of Clauses 1 to 5, wherein the group 8-10 metals comprise Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt or combinations thereof.

[0138] Clause 7. The method according to any one of Clauses 1 to 6, wherein the Group 8-10 metals comprise Ni, Fe, Co, or combinations thereof.

[0139] Clause 8. The method according to any one of Clauses 1 to 7, wherein the first precursor comprising copper is formed by introducing a copper source into an amine.

[0140] Clause 9. The method according to any one of Clauses 1 to 8, wherein the third precursor is formed by introducing a Group 8-10 metal source into an amine.

[0141] Clause 10. The method according to any one of Clauses 1 to 9, wherein:

[0142] The first precursor containing copper is formed by introducing a copper source into a first amine;

[0143] The third precursor is formed by introducing a group 8-10 metal source into a second amine; and

[0144] The first amine and the second amine may be the same or different.

[0145] Clause 11. The method described in accordance with Clause 10, wherein:

[0146] The first amine comprises tetradecylamine, oleylamine, octadecylamine, hexadecylamine, dodecylamine, or combinations thereof; and

[0147] The second amine comprises tetradecylamine, oleylamine, octadecylamine, hexadecylamine, dodecylamine, or combinations thereof.

[0148] Clause 12. The method according to any one of Clauses 1 to 11, wherein the X-ray diffraction pattern of the bimetallic structure has {111}, {200} and {220} diffraction peaks.

[0149] Clause 13. A bimetallic structure comprising:

[0150] A core comprising copper and group 8-10 metals, wherein the core has a greater amount of copper than the group 8-10 metals;

[0151] A shell comprising copper and Group 8-10 metals, wherein the amount of the Group 8-10 metals is greater than that of copper; and

[0152] One or more ligands, said one or more ligands bonded to the copper of the core, the copper of the shell, the group 8-10 metal of the core, the group 8-10 metal of the shell, or a combination thereof, wherein:

[0153] At least one of the one or more ligands includes a nitrogen-containing ligand, and

[0154] At least one of the one or more ligands includes a phosphorus-containing ligand.

[0155] Clause 14. The bimetallic structure according to Clause 13, wherein the bimetallic structure has the following formula:

[0156] (Cu) a (M) b (P) c (N) d ,

[0157] in:

[0158] M represents the metals of Groups 8-10;

[0159] The molar ratio of a:b is approximately 1:99 to approximately 99:1; and

[0160] The molar ratio of a:(c+d) is approximately 500:1 to approximately 1:1.

[0161] Clause 15. The bimetallic structure according to Clause 13 or Clause 14, wherein the nitrogen-containing ligand comprises oleylamine (OLA), octadecylamine (ODA), hexadecylamine (HDA), dodecylamine (DDA), tetradecylamine (TDA), isomers thereof, derivatives thereof, or combinations thereof.

[0162] Clause 16. The bimetallic structure according to any one of Clauses 13 to 15, wherein the phosphorus-containing ligand comprises alkylphosphine, arylphosphine, or a combination thereof.

[0163] Clause 17. The bimetallic structure according to any one of Clauses 13 to 16, wherein the phosphorus-containing ligand comprises trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, trioctylphosphine, tricyclohexylphosphine, diethylphosphine, dibutylphosphine, diphenylphosphine, dimethylethylphosphine, triphenylphosphine, isomers thereof, derivatives thereof, and combinations thereof.

[0164] Clause 18. The bimetallic structure according to any one of Clauses 13 to 17, wherein:

[0165] The group 8-10 metals include Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, or combinations thereof;

[0166] The bimetallic structure is characterized by having a face-centered cubic structure, as determined by X-ray diffraction; or

[0167] It has both of these characteristics.

[0168] Clause 19. A method for forming a transformation product, the method comprising:

[0169] Introducing reactants into the bimetallic structure described herein; and

[0170] The conversion product is obtained.

[0171] Clause 20. A method for forming a transformation product, the method comprising:

[0172] Introducing reactants into a bimetallic structure; and

[0173] The transformation product is formed by the bimetallic structure comprising copper (Cu), group 8-10 metals (M), phosphorus (P), and nitrogen (N), and the bimetallic structure has the formula...

[0174] (Cu) a (M) b (P) c (N) d ,

[0175] in:

[0176] The molar ratio of a:b is approximately 1:99 to approximately 99:1; and

[0177] The molar ratio of c:d is approximately 1:100 to approximately 1:20.

[0178] Clause 21. The method according to Clause 20, wherein the bimetallic structure is a polyhedral particle having more than four faces as determined by scanning electron microscopy.

[0179] Clause 22. A metal particle, said metal particle comprising:

[0180] A core comprising copper and group 8-10 metals, wherein the core has a greater amount of copper than the group 8-10 metals;

[0181] A shell comprising copper and Group 8-10 metals, wherein the amount of the Group 8-10 metals is greater than that of copper; and

[0182] One or more ligands, said one or more ligands bonded to the copper of the core, the copper of the shell, the group 8-10 metal of the core, the group 8-10 metal of the shell, or a combination thereof, wherein:

[0183] At least one of the one or more ligands includes a nitrogen-containing ligand, and

[0184] At least one of the one or more ligands includes a phosphorus-containing ligand.

[0185] Clause 23. The metal particles according to Clause 22, wherein the metal particles have the following formula:

[0186] (Cu) a (M) b (P) c (N) d ,

[0187] in:

[0188] M represents the metals of Groups 8-10;

[0189] The molar ratio of a:b is approximately 1:99 to approximately 99:1; and

[0190] The molar ratio of a:(c+d) is approximately 500:1 to approximately 1:1.

[0191] Clause 24. The metal particles according to Clause 22 or Clause 23, wherein the amount of copper in the core is greater than, less than or equal to the amount of Group 8-10 metals in the core.

[0192] Clause 25. Metal particles according to any one of Clauses 22 to 24, wherein the amount of Group 8-10 metals in the shell is greater than, less than or equal to the amount of copper in the shell.

[0193] Clause 26. Metal particles according to any one of Clauses 21 to 25, wherein the Group 8-10 metals comprise Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, or combinations thereof.

[0194] Clause 27. Metal particles according to any one of Clauses 21 to 26, wherein:

[0195] The average particle size of the metal particles, as determined by transmission electron microscopy, is approximately 5 nm to approximately 2000 μm.

[0196] The metal particles are characterized by having a face-centered cubic structure, as determined by X-ray diffraction; or

[0197] It has both of these characteristics.

[0198] As used herein, and unless otherwise stated, the term "C" is used in conjunction with other terms. n "C" refers to hydrocarbons with n carbon atoms per molecule, where n is a positive integer. The term "hydrocarbon" refers to a class of compounds containing hydrogen atoms bonded to carbon, and encompasses (i) saturated hydrocarbons, (ii) unsaturated hydrocarbons, and (iii) mixtures of hydrocarbons (saturated and / or unsaturated), including mixtures of hydrocarbons with different n values. Similarly, "C" m -C y "A group or compound refers to a group or compound containing a total number of carbon atoms ranging from m to y. Therefore, C1-C..." 50 Alkyl groups are alkyl groups containing a total number of carbon atoms ranging from 1 to 50.

[0199] For the purposes of this disclosure, and unless otherwise stated, the terms "hydrocarbylradical," "hydrocarbyl group," or "hydrocarbyl" are interchangeable to refer to a group consisting only of hydrogen and carbon atoms. Hydrocarbyl groups can be saturated or unsaturated, straight-chain or branched, cyclic or acyclic, aromatic or non-aromatic. For the purposes of this disclosure, and unless otherwise stated, the term "aryl" refers to a hydrocarbon group containing an aromatic ring structure.

[0200] Unless otherwise stated, the chemical portion of this application may be substituted or unsubstituted. For the purposes of this disclosure, and unless otherwise stated, substituted hydrocarbon and substituted aryl refer to hydrocarbon and aryl groups, respectively, wherein at least one hydrogen atom has been substituted by a heteroatom or a heteroatom-containing group, such as by at least one functional group, such as one or more elements of Groups 13-17 of the periodic table, such as halogens (F, Cl, Br, or I), O, N, Se, Te, P, As, Sb, S, B, Si, Ge, Sn, Pb, etc., such as NR*2, OR* (e.g., OH or O2H), SeR*, TeR*, PR*2, AsR*2, SbR*2, SR*, SO x(where x = 2 or 3), BR*2, SiR*3, GeR*3, SnR*3, PbR*3, etc., or at least one heteroatom of which has been inserted into a hydrocarbon or aryl group, such as one or more of the following: halogens (F, Cl, Br or I), O, S, Se, Te, NR*, PR*, AsR*, SbR*, BR*, SiR*2, GeR*2, SnR*2, PbR*2, etc., where R* is independently hydrogen or a hydrocarbon group (e.g., C1-C). 10 ), or two or more R* can be linked together to form substituted or unsubstituted fully saturated, partially unsaturated, fully unsaturated structures or aromatic ring structures or polycyclic structures.

[0201] If isomers of a named molecular group exist (e.g., n-butyl, isobutyl, sec-butyl, and tert-butyl), referring to a member of the group (e.g., n-butyl) should explicitly disclose the remaining isomers in the family (e.g., isobutyl, sec-butyl, and tert-butyl). Similarly, referring to a named molecule without specifying a particular isomer (e.g., butyl) explicitly discloses all isomers (e.g., n-butyl, isobutyl, sec-butyl, and tert-butyl).

[0202] As used herein, a “composition” may include components of the composition and / or reaction products of two or more components of the composition. The compositions disclosed herein can be prepared by any suitable method. As used herein, a “bimetallic structure” may include components of a bimetallic structure and / or reaction products of two or more components of a bimetallic structure. The bimetallic structures disclosed herein can be prepared by any suitable method.

[0203] It will be apparent from the foregoing general description and specific aspects that, while various forms have been illustrated and described, various modifications may be made without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not intended to be limited thereto. Similarly, the term “comprising” is considered synonymous with the term “including.” Likewise, whenever the transitional phrase “comprising” precedes a composition, element, or group of elements, it should be understood that the same composition or group of elements is also contemplated to have the transitional phrases “consistently composed of,” “composed of,” “selected from,” or “is” preceding the detailed description of the composition or one or more elements, and vice versa; for example, the terms “comprising,” “consistently composed of,” and “composed of” also include the product of combinations of elements listed after that term. Similarly, whenever a bimetallic structure, element, or group of elements is preceded by the transitional phrase “comprising”, it should be understood that the bimetallic structure or group of elements is also envisioned to have the transitional phrases “substantially composed of…”, “composed of…”, “selected from…”, or “for” preceding the bimetallic structure, one or more elements, and vice versa. For example, the terms “comprising,” “substantially composed of…”, and “composed of…” also include the product of a combination of elements listed after the terms.

[0204] For the purposes of this disclosure, and unless otherwise specified, all numerical values ​​in the detailed descriptions and claims herein are indicated by “about” or “approximately”, taking into account experimental errors and variations that would be expected by one of ordinary skill in the art. For the sake of brevity, only certain ranges are explicitly disclosed herein. However, a range beginning with any lower limit may be combined with any upper limit to enumerate ranges not explicitly enumerated, and a range beginning with any lower limit may be combined with any other lower limit to enumerate ranges not explicitly enumerated, and in the same manner, a range beginning with any upper limit may be combined with any other upper limit to enumerate ranges not explicitly enumerated. Furthermore, even if not explicitly enumerated, a range includes every point or individual value between its endpoints. Thus, each point or individual value may be used as its own lower or upper limit, combined with any other point or individual value or any other lower or upper limit, to enumerate ranges not explicitly enumerated.

[0205] As used herein, the indefinite article “a” or “an” should mean “at least one” unless otherwise indicated by the contrary or by the context.

[0206] While the foregoing relates to aspects of this disclosure, other and further aspects of this disclosure may be designed without departing from the basic scope of the invention, the scope of which is defined by the appended claims.

Claims

1. A method of forming a bimetallic polyhedral nanoparticle, comprising: forming a mixture comprising a copper alkylamine and a trialkylphosphine, the mixture having a molar ratio of copper alkylamine to trialkylphosphine of 10: 1 to 1 : 10; heating the mixture to an injection temperature of 200 °C to 320 °C; introducing a Group 8-10 metal alkylamine with the heated mixture, the Group 8-10 metal in the Group 8-10 metal alkylamine being selected from the group consisting of Fe, Co, and Ni; and reacting the resulting mixture at a reaction temperature of 200 °C to 320 °C to form a copper-containing bimetallic polyhedral nanoparticle, the copper-containing bimetallic polyhedral nanoparticle having an average particle size of 50 nm to 350 nm, the copper-containing bimetallic polyhedral nanoparticle comprising a dodecahedral structure.

2. The method of claim 1, wherein, the trialkylphosphine is selected from the group consisting of trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, trioctylphosphine, tricyclohexylphosphine, dimethylethylphosphine, isomers thereof, and combinations thereof.

3. The method of claim 1, wherein, the copper alkylamine is formed from a copper source selected from the group consisting of copper acetate, copper halide, copper nitrate, and combinations thereof.

4. The method of claim 1, wherein, the Group 8-10 metal alkylamine is formed from a Group 8-10 metal source selected from the group consisting of metal chloride, metal nitrate, metal acetylacetonate, and combinations thereof.

5. The method of claim 1, wherein, the alkylamine of the copper alkylamine is selected from the group consisting of myristylamine, oleylamine, stearylamine, cetylamine, laurylamine, and combinations thereof.

6. The method of claim 1, wherein, the alkylamine of the Group 8-10 metal alkylamine is selected from the group consisting of myristylamine, oleylamine, stearylamine, cetylamine, laurylamine, and combinations thereof.

7. The method of claim 1, wherein, the trialkylphosphine is selected from the group consisting of trioctylphosphine, tributylphosphine, and combinations thereof.

8. The method of claim 1, wherein, the Group 8-10 metal in the Group 8-10 metal alkylamine is selected from the group consisting of Fe and Co.

9. The method of claim 8, wherein, the copper-containing bimetallic polyhedral nanoparticle is in the form of a core-shell structure; the core of the core-shell structure comprises copper and the Group 8-10 metal, the core having a greater amount of copper than the Group 8-10 metal; and the shell of the core-shell structure comprises copper and the Group 8-10 metal, the shell having a greater amount of the Group 8-10 metal than copper.

10. The method of claim 1, wherein, the Group 8-10 metal in the Group 8-10 metal alkylamine is Ni.

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