Patent Application
20220288551
The present disclosure relates generally to multielement material synthesis, and more particularly, to systems and methods for determination of a composition of multielement material (e.g., nanocluster, nanoparticle, or bulk material) for a particular application via combinatorial synthesis and screening.
Nanoparticles with a range of sizes and morphologies have been studied for various catalytic applications. These nanoparticles are typically comprised of no more than three elements to avoid synthetic complexity and structural heterogeneity. Multielement nanoclusters having three or more elements thus present a vast and largely undiscovered chemical space that can offer synergistic interactions between different elements. Yet, with increasing compositional complexity, conventional fabrication methods can lead to multielement particles with large size distributions and/or inhomogeneous structures (e.g., phase separation and/or elemental segregation within the particles), which may result from the inability of conventional fabrication methods to control the kinetics and dynamics of chemical reactions at the nanoscale among dissimilar constituent elements. As a result, it remains a challenge to tune the composition of fabricated materials in order to systematically study the properties thereof, thus limiting material discovery, property optimization, and mechanistic understanding for different functionalities.
Embodiments of the disclosed subject matter may address one or more of the above-noted problems and disadvantages, among other things.
Embodiments of the disclosed subject matter system provide systems and methods for combinatorial synthesis and screening of multielement materials, for example, multielement nanoclusters, nanoparticles, or bulk materials. Multielement nanomaterials hold great promise for various applications due to their widely tunable surface chemistries. Yet it remains challenging to efficiently study this multi-dimensional space because conventional approaches are typically slow and depend on serendipity. Embodiments of the disclosed subject matter can thus address these deficiencies by offering a high-throughput technique for combinatorial compositional design (e.g., formulation in solution phases) and rapid synthesis (e.g., rapid, high-temperature exposure on the order of seconds) of multielement (e.g., multimetallic) materials (e.g., nanoparticles, nanoclusters, and/or bulk materials) with a homogeneous structure. The materials with different compositions can be subject to rapid screening, for example, to discover optimal and/or synergistic compositions for particular applications, such as but not limited to use as a catalyst, a plasmonic nanoparticle, an energy storage device, an optoelectronic device, a solid-state electrolyte, an ion conductive membrane, a fluorescent material, a component thereof, or any combination of the foregoing.
In one or more embodiments, a method can comprise depositing one or more first precursors on a first portion of a substrate and depositing one or more second precursors on a second portion of the substrate. The second portion can be spaced from the first portion. The method can further comprise subjecting each of the first and second portions of the substrate to a first temperature for a first time period so as to convert the deposited one or more first precursors into a first material and to convert the deposited one or more second precursors into a second material. The first material can have a different composition than the second material. The first temperature can be greater than or equal to about 500° C., and a duration of the first time period can be less than about 60 seconds. In some embodiments, the method can further comprise testing each of the first and second materials with respect to an electrical property, a chemical property, an optical property, or any combination thereof. In some embodiments, the method can also comprise determining a composition of a material for use in a predetermined application based at least in part on results of the testing.
In one or more embodiments, a system can comprise a dispensing device, a heating device, and a control system. The dispensing device can have a nozzle facing a surface of a substrate and constructed to deposit precursors onto the substrate. At least one of the nozzle and the substrate can be movable with respect to the other. The heating device can be constructed to generate a first temperature of at least 500° C. The control system can be operatively coupled to the dispensing device and the heating device. The control system can comprise one or more processors and computer readable storage media. The computer readable storage media can store instructions that, when executed by the one or more processors, cause the control system to (i) control the dispensing device to position the nozzle with respect to a first portion of the substrate, (ii) deposit, via the nozzle, one or more first precursors on the first portion, (iii) control the dispensing device to position the nozzle with respect to a second portion of the substrate, the second portion being spaced from the first portion, (iv) deposit, via the nozzle, one or more second precursors on the second portion, and (v) subject, via the heating device, each of the first and second portions of the substrate to the first temperature for a first time period so to convert the deposited one or more first precursors into a first material and to convert the deposited one or more second precursors into a second material. The first material can have a different composition than the second material, and a duration of the first time period can be less than 60 seconds.
Any of the various innovations of this disclosure can be used in combination or separately. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
Embodiments will hereinafter be described with reference to the accompanying drawings, which have not necessarily been drawn to scale. Where applicable, some elements may be simplified or otherwise not illustrated in order to assist in the illustration and description of underlying features. Throughout the figures, like reference numerals denote like elements.
For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present, or problems be solved. The technologies from any embodiment or example can be combined with the technologies described in any one or more of the other embodiments or examples. In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are exemplary only and should not be taken as limiting the scope of the disclosed technology.
Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. Additionally, the description sometimes uses terms like “provide” or “achieve” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by one skilled in the art.
The disclosure of numerical ranges should be understood as referring to each discrete point within the range, inclusive of endpoints, unless otherwise noted. Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, percentages, temperatures, times, and so forth, as used in the specification or claims are to be understood as being modified by the term “about.” Accordingly, unless otherwise implicitly or explicitly indicated, or unless the context is properly understood by a person skilled in the art to have a more definitive construction, the numerical parameters set forth are approximations that may depend on the desired properties sought and/or limits of detection under standard test conditions/methods, as known to those skilled in the art. When directly and explicitly distinguishing embodiments from discussed prior art, the embodiment numbers are not approximates unless the word “about” is recited. Whenever “substantially,” “approximately,” “about,” or similar language is explicitly used in combination with a specific value, variations up to and including 10% of that value are intended, unless explicitly stated otherwise.
Directions and other relative references may be used to facilitate discussion of the drawings and principles herein, but are not intended to be limiting. For example, certain terms may be used such as “inner,” “outer,”, “upper,” “lower,” “top,” “bottom,” “interior,” “exterior,” “left,” right,” “front,” “back,” “rear,” and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated embodiments. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” part can become a “lower” part simply by turning the object over. Nevertheless, it is still the same part and the object remains the same.
As used herein, “comprising” means “including,” and the singular forms “a” or “an” or “the” include plural references unless the context clearly dictates otherwise. The term “or” refers to a single element of stated alternative elements or a combination of two or more elements, unless the context clearly indicates otherwise.
Although there are alternatives for various components, parameters, operating conditions, etc. set forth herein, that does not mean that those alternatives are necessarily equivalent and/or perform equally well. Nor does it mean that the alternatives are listed in a preferred order, unless stated otherwise. Unless stated otherwise, any of the groups defined below can be substituted or unsubstituted.
Unless explained otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one skilled in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and examples are illustrative only and not intended to be limiting. Features of the presently disclosed subject matter will be apparent from the following detailed description and the appended claims.
The following explanations of specific terms and abbreviations are provided to facilitate the description of various aspects of the disclosed subject matter and to guide those skilled in the art in the practice of the disclosed subject matter.
Thermal shock: Application of a sintering temperature for a time period having a duration less than about 60 seconds. In some embodiments, the duration of the time period of sintering temperature application is in a range of about 0.5 seconds to about 30 seconds, inclusive.
Sintering temperature: A maximum temperature at a surface of a heating element when energized (e.g., by application of a current pulse). In some embodiments, the sintering temperature is at least about 500° C., for example, in a range of about 1000 to about 3000° C. In some embodiments, a temperature at a material being sintered (e.g., precursors on a substrate) within the furnace can match or substantially match (e.g., within 10%) the temperature of the heating element.
Particle size: A maximum cross-sectional dimension (e.g., diameter) of particle. In some embodiments, an identified particle size represents an average particle size for all particles in a particular sample (e.g., an average of the maximum cross-sectional dimensions).
Nanoparticle: A particle composed of at least two different elements and having a particle size less than or equal to about 1 μm. In some embodiments, each nanoparticle has a size of about 100 nm or less, for example, about 25 nm or less.
Nanocluster: A particle composed of at least two different elements and having a particle size less than or equal to about 2 nm.
Bulk material: A material composed of at least two different elements and having at least one dimension greater than or equal to about 1 mm.
Precursor: One or more materials that, when subjected to thermal shock, are converted to a nanoparticle, nanocluster, or bulk material. In some embodiments, the precursors can comprise metal salts and/or metal oxides that, when subjected to thermal shock, are converted to a homogeneous mixture of metals. Alternatively or additionally, the precursors can be converted via thermal shock to a ceramic (e.g., oxide, nitride, etc.), carbon, heterogeneous or hybrid structure, composite, metal, or any combination of the foregoing.
Refractory material: A material (e.g., element or compound) having a melting temperature of at least 1000° C., for example, at least 1580° C. In some embodiments, a refractory material can be as defined in ASTM C71-01, “Standard Terminology Relating to Refractories,” August 2017, which is incorporated herein by reference.
Refractory metal: A metal or metal alloy having a melting point of at least 1000° C., for example, at least 1850° C. In some embodiments, a refractory metal is one of niobium, molybdenum, tantalum, tungsten, rhenium, or an alloy thereof.
Metal: Includes those individual chemical elements classified as metals on the periodic table, including alkali metals, alkaline earth metals, transition metals, lanthanides, and actinides, as well as alloys formed from such metals, such as, but not limited to, stainless steel, brass, bronze, monel, etc.
In one or more embodiments, a combinatorial approach can provide parallel (or pseudo-parallel) synthesis of a large number (e.g., tens, hundreds, thousands, etc.) of samples of different material compositions comprised of multiple elements (e.g., at least two, such as three or more), thereby saving tremendous time and effort. In some embodiments, all of the samples (or at least a subset thereof) can be provided on a common substrate, for example, for part of the synthesis process (e.g., simultaneous or sequential thermal shock of each sample spot on the substrate) and/or subsequent screening (e.g., simultaneous or sequential testing of each sample spot on the substrate). After synthesis, high throughput screening can rapidly acquire data indicative of one or more properties of these compositionally different multielement materials (e.g., nanoparticles, nanoclusters, or functional bulk materials). By combining combinatorial synthesis and high throughput screening, rapid material discovery and exploration in new multielement dimensions becomes possible.
One or more embodiments can include (a) multielement composition design, (b) a combinatorial precursor mapping for a large number (e.g., at least 20, at least 50, at least 100, or at least 1000) of different compositions, (c) thermal shock heating that synthesizes materials with similar structures (e.g., particle size, particle dispersion density, single phase, homogeneous distribution, etc.) despite otherwise different compositions; and (d) high throughput screening of compositionally different samples with respect to targeted properties. In some embodiments, the multielement composition design can comprise selection of particular elements for combination (e.g., from a subset of Pt, Pd, Rh, Ru, Ir, Fe, Co, Au, Mn, and Ni) and/or selection of number of elements per particle (e.g., three elements per particle) or a range of number of elements per particle (e.g., in a range of three to eight elements per particle).
In some embodiments, the combinatorial precursor mapping can include varying element compositions in a spatial arrangement (e.g., composition of one element varying in a stepwise gradual manner along one linear dimension, for example, an element composition for a plurality of samples varying from 1% at one end of the substrate to 99% at an opposite end of the substrate in increments of 1%) or any other predetermined manner. For example, the mapping can utilize a mathematical object in which all possible combinations of elements are covered at least once, similar to a covering array. Alternatively or additionally, a combinatorial algorithm, such as group testing algorithms, can be employed to determine variations of element compositions of the multielement materials for analysis, either formed on a common substrate or spread across multiple substrates.
In some embodiments, the thermal shock heating can be performed on multiple sample spots at time, for example, to simultaneously form multielement materials on the substrate having different material compositions for analysis. For example, the systems and methods for thermal shock heating and/or the multielement materials formed by thermal shock heating can be similar to those disclosed in U.S. Publication No. 2018/0369771, entitled “Nanoparticles and systems and methods for synthesizing nanoparticles through thermal shock,” U.S. Publication No. 2019/0161840, entitled “Thermal shock synthesis of multielement nanoparticles,” International Publication No. WO 2020/236767, entitled “High temperature sintering systems and methods,” and International Publication No. WO 2020/252435, entitled “Systems and methods for high temperature synthesis of single atom dispersions and multi-atom dispersions,” all of which are incorporated by reference herein.
In some embodiments, the high throughput screening can evaluate the plurality of multielement samples on the substrate with respect to one or more properties, such as but not limited to electrical properties (e.g., conductivity, resistance, impedance, etc.), chemical properties (e.g., catalytic or electrocatalytic effect, electrochemical impedance, etc.), optical property (e.g., plasmonic effect, fluorescence, etc.), or any combination thereof. In some embodiments, the high throughput screening can interrogate and evaluate each multielement sample spot on the substrate individually, for example, in a sequential manner. Alternatively or additionally, in some embodiments, the high throughput screening can interrogate and evaluate each multielement sample spot on the substrate collectively, for example, in a parallel manner.
Some embodiments can further include (e) integrating feedback from the screening to direct selection of multielement compositions for further combinatorial synthesis and screening (e.g., by repeating (a)-(d)). For example, once one or more samples are identified as potential options for the predetermined application during an initial iteration of the combinatorial synthesis and screening, a smaller region of diversity space around the one or more identified samples can be probed by a subsequent iteration of the combinatorial synthesis and screening to find improved or additional options. In some embodiments, the feedback can employ optimization algorithms (e.g., a genetic algorithm), data mining, and/or machine learning to determine sample compositions for further screening and/or use in the predetermined application. Some embodiments can further include (f) selection of one or more compositions based on the one or more screenings for use in the predetermined application. Such applications can include but are not limited to use as (i) a catalyst, (ii) a plasmonic nanoparticle, (iii) an energy storage device, (iv) an optoelectronic device, (v) a solid-state electrolyte, (vi) an ion conductive membrane, (vii) a fluorescent material, (viii) a component of any of (i)-(vii), or any combination of (i)-(viii).
In some embodiments, the dispensing device 104 can also include a support 112, for example, a movable or stationary platform where a substrate can be disposed. The dispensing device 104 can further include one or more actuators 110. In some embodiments, the actuator(s) 110 can be coupled to nozzle 108 to position the nozzle 108 with respect to the substrate. Alternatively or additionally, in some embodiments, the actuator(s) 110 can be coupled to support 112 to position the substrate with respect to the nozzle 108. The actuator(s) 110 can thus provide motion in at least one dimension, for example, two dimensions parallel to a deposition surface of the substrate, or, in some embodiments, three dimensions (e.g., to change a vertical spacing between the nozzle 108 and the deposition surface of the substrate). In some embodiments, the dispensing device 104 can be an ink jet printhead, an additive manufacturing printhead (e.g., 3D printer), a robotic pipetting device, or any other mechanism for controlled dispensing of fluids (e.g., inks, suspensions, slurries, etc.).
The heating device 116 can be constructed to apply a thermal shock, for example, by providing a temperature in excess of 500° C. (e.g., in a range of 1000-3000° C., inclusive) for a time period less than 60 seconds (e.g., in a range of 0.5 to 30 seconds, inclusive). In some embodiments, the heating device 116 can comprise a Joule heating (e.g., with the heating element in contact with the precursors to provide conductive heating and/or spaced from the precursors to provide radiation heating), microwave heating, laser heating, plasma heating, or any combination thereof.
In some embodiments, the synthesis system 102 can include one or more transport mechanisms 120 to convey the substrate from the dispensing device 104 to the heating device 116. Alternatively or additionally, the synthesis system 102 can include one or more transport mechanisms 122 to convey the substrate from the heating device 116. In some embodiments, the transport mechanism 122 may be combined with and/or considered part of transport mechanism 120. Alternatively, in some embodiments, transport mechanism 122 may be separate from and/or operate independently of transport mechanism 120. For example, in some embodiments, the transport mechanism 120, transport mechanism 122, or both can comprise a conveyor system (e.g., comprising one or more belts and/or rollers). Alternatively or additionally, in some embodiments, either or both of the transport mechanisms 120, 122 can comprise a pick-and-place robot, magnetic actuators, pneumatic or vacuum actuators, or any other transport mechanism.
Synthesis system 102 can further include a control sub-system 118, which can be operatively coupled to the various components of synthesis system 102, e.g., dispensing device 104, heating device 116, and/or transport mechanisms 120, 122, to direct operation thereof. For example, the control sub-system 118 can control the dispensing device 104 to dispense precursors at a plurality of sample spots on the substrate with different elemental compositions according to a combinatorial approach. After dispensing of the precursors, the control sub-system 118 can direct transport mechanism 120 to move the substrate to heating device 116 and to control the heating device 116 to generate a thermal shock. The thermal shock can be effective to convert the precursors at each sample spot 126 to a substantially homogeneous solid mixture of multiple elements (e.g., multielement material, such as multielement nanoparticle 128). Since the precursors were loaded across the substrate 124 according to the combinatorial approach, each of the sample spots can have a different material composition. Despite the different material compositions, the thermal shock treatment can be effective to generate materials that otherwise have substantially similar particle sizes and uniformity, which features can be useful for subsequent screening and comparison of material properties.
The control sub-system 118 can direct transport mechanism 122 to move the substrate 124, with sample spots having different material compositions thereon, from the heating device 116 for subsequent screening, for example, via a separate screening system or via an integrated screening system. For example,
In some embodiments, the evaluation device 134 can also include a support 140, for example, a movable or stationary platform where the substrate can be disposed. The evaluation device 134 can further include one or more actuators 138. In some embodiments, the actuator(s) 138 can be coupled to probe head 136 to position the probe head 136 with respect to the substrate. Alternatively or additionally, in some embodiments, the actuator(s) 138 can be coupled to support 140 to position the substrate with respect to the probe head 136. The actuator(s) 138 can thus provide motion in at least one dimension, for example, two dimensions parallel to a deposition surface of the substrate, or, in some embodiments, three dimensions (e.g., to change a vertical spacing between the probe head 136 and the sample spots on the substrate). In some embodiments, the evaluation device 134 is configured to perform parallel testing of sample spots, for example, to interrogate multiple sample spots at once. For example, optical radiation can be directed at multiple spots on the substrate, and the multiple spots imaged simultaneously. Alternatively or additionally, in some embodiments, the evaluation device 134 operates in a serial manner, for example, by testing a single sample spot at a time.
Screening system 132 can further include a control sub-system 148, which can be operatively coupled to the various components of screening system 132, e.g., evaluation device 134, input/output (I/O) interface 144, and/or database 142, to direct operation thereof. In some embodiments, control sub-system 148, control sub-system 118, I/O interface 144, and/or database 142 can be considered part of a system-wide control system 146. Alternatively, in some embodiments, control sub-system 148 and control sub-system 118 may be considered separate from each other, although in some cases the control sub-systems may communicate with each other, for example, to coordinate transfer of a substrate from synthesis system 102 and screening system 132 via transport mechanism 122.
In some embodiments, the control sub-system 148 can control the evaluation device 134 to test one, some, or all of the sample spots on the substrate with respect to one or more material properties. The resulting data can be stored in database 142 for further processing. Alternatively or additionally, in some embodiments, the control sub-system 148 can be configured to analyze the data to determine an optimal material composition for a particular application. In some embodiments, the control sub-system 148 can provide feedback to synthesis system 102 (e.g., via communication with control sub-system 118) regarding material compositions that should be further investigated in a subsequent combinatorial synthesis iteration, for example, by investigating material compositions in a vicinity of a highest scoring material from a prior combinatorial synthesis run. Alternatively or additionally, the control sub-system 148 can employ data mining techniques and/or machine learning (e.g., with or without consideration of data from prior combinatorial synthesis runs stored in database 142) to identify material compositions that should be further investigated in a subsequent combinatorial synthesis iteration. Alternatively or additionally, the control sub-system 148 may simply select one of the tested sample spots from the substrate that has the best material properties for the particular application (or a set of test sample spots that have the top material properties). I/O interface 144 can be used to communicate results of the screening to a human user (e.g., via a graphical display) and/or to accept input from a human user (e.g., to direct material compositions of a subsequent combinatorial synthesis iteration and/or control system operations).
At stage 200, nozzle 202 can be aligned with a first spot location, for example, by moving nozzle 202 with respect to substrate 214, by moving substrate 214 with respect to the nozzle 202, or both. A predetermined first amount of first precursor (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the spot location) can be dispensed from first reservoir 206 to the first spot location via nozzle 202, thereby forming first sample 216a. As shown at stage 220, the nozzle 202 can then be aligned with a second spot location, for example, by moving the nozzle 202 and/or the substrate 214, and a predetermined second amount of first precursor (which second amount may be different than that of the first precursor sample 216a) can be dispensed from first reservoir 206 to the second spot location via nozzle 202, thereby forming second sample 218a. As shown at stage 222, the nozzle 202 can then be aligned with a third spot location, for example, by moving the nozzle 202 and/or the substrate 214, and a predetermined third amount of first precursor (which third amount may be different than that of first sample 216a and/or second sample 218a) can be dispensed from first reservoir 206 to the third spot location via nozzle 202, thereby forming third sample 224a.
The nozzle 202 can then reconfigure for deposition of the second precursor on the same spot locations (e.g., thereby mixing the precursors in place on the substrate). For example, the valve 204 can switch orientations to couple the second reservoir 208 of supply 212 to nozzle 202. At stage 226, nozzle 202 can be re-aligned with the first spot location by moving the nozzle 202 and/or the substrate 214, and a predetermined fourth amount of second precursor (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the spot location) can be dispensed from second reservoir 208 to the first spot location via nozzle 202, thereby forming a first mixed sample 216b (e.g. formed of a first amount of first precursor and a fourth amount of second precursor). As shown at stage 228, the nozzle 202 can then be re-aligned with the second spot location, for example, by moving the nozzle 202 and/or the substrate 214, and a predetermined fifth amount of second precursor (which fifth amount may be different than the fourth amount of second precursor in sample 216b) can be dispensed from second reservoir 208 to the second spot location via nozzle 202, thereby forming second mixed sample 218b. As shown at stage 230, the nozzle 202 can then be re-aligned with the third spot location, for example, by moving the nozzle 202 and/or the substrate 214, and a predetermined sixth amount of second precursor (which sixth amount may be different than the fourth amount of second precursor in sample 216b and/or the fifth amount of second precursor in sample 218b) can be dispensed from second reservoir 208 to the third spot location via nozzle 202, thereby forming third mixed sample 224b.
The nozzle 202 can then reconfigure again for deposition of the third precursor on the same spot locations (e.g., thereby mixing the precursors in place on the substrate). For example, the valve 204 can switch orientations to couple the third reservoir 210 of supply 212 to nozzle 202. At stage 232, nozzle 202 can be re-aligned with the first spot location by moving the nozzle 202 and/or the substrate 214, and a predetermined seventh amount of third precursor (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the spot location) can be dispensed from third reservoir 210 to the first spot location via nozzle 202, thereby forming a first final sample 216c (e.g. formed of a combination of a first amount of first precursor, a fourth amount of second precursor, and a seventh amount of third precursor). As shown at stage 234, the nozzle 202 can then be re-aligned with the second spot location, for example, by moving the nozzle 202 and/or the substrate 214, and a predetermined eighth amount of third precursor (which eighth amount may be different than the seventh amount of third precursor in sample 216c) can be dispensed from third reservoir 210 to the second spot location via nozzle 202, thereby forming second final sample 218c. As shown at stage 236, the nozzle 202 can then be re-aligned with the third spot location, for example, by moving the nozzle 202 and/or the substrate 214, and a predetermined ninth amount of third precursor (which ninth amount may be different than the seventh amount of third precursor in sample 216c and/or the eighth amount of third precursor in sample 218c) can be dispensed from third reservoir 210 to the third spot location via nozzle 202, thereby forming third final sample 224c.
The reconfiguration of nozzle 202 and deposition of precursor can be repeated any number of times according to the composition defined by the combinatorial approach. After depositing of all sample spots, the substrate 214 can be subjected to thermal shock as described elsewhere herein, so as to form an array of multielement materials of different compositions on the substrate for subsequent screening. Alternatively, in some embodiments, after dispensing of one precursor (e.g., after deposition of first precursor in stage 222, after deposition of second precursor in stage 230, and/or after deposition of third precursor in stage 236) on all desired spots of the substrate 214, the substrate 214 can be subjected to thermal shock or at least to a thermal treatment prior to beginning dispensing of the next precursor. In some embodiments, such independent treatment of the precursors may help in mixing the elements of the deposited precursor with elements from subsequent precursor depositions. Alternatively or additionally, the system can proceed with deposition of additional precursor depositions on spot locations without an intervening thermal shock.
In some embodiments, instead of independent deposition of separate precursors on each spot location on the substrate, precursors can be premixed according to desired compositions and then applied directly to a corresponding spot location. For example,
Although
At stage 240, nozzle 202 can be aligned with a first spot location, for example, by moving nozzle 202 with respect to substrate 214, by moving substrate 214 with respect to the nozzle 202, or both. A predetermined amount of first premixed precursors (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the spot location) can be dispensed from first reservoir 244 to the first spot location via nozzle 202, thereby forming first sample 250. As shown at stage 254, the nozzle 202 can then be aligned with a second spot location, for example, by moving the nozzle 202 and/or the substrate 214, and the valve 204 can switch orientations to couple the second reservoir 246 of supply 242 to nozzle 202. A predetermined amount of second premixed precursor (which amount may be substantially the same as that of the first premixed precursor forming first sample 250) can then be dispensed from second reservoir 246 to the second spot location via nozzle 202, thereby forming second sample 252.
As shown at stage 258, the nozzle 202 can then be aligned with a third spot location, for example, by moving the nozzle 202 and/or the substrate 214, and the valve 204 can switch orientations to couple the third reservoir 248 of supply 242 to nozzle 202. A predetermined amount of third premixed precursor (which amount may be substantially the same as that of the first premixed precursor forming first sample 250 and/or the second premixed precursor forming second sample 252) can then be dispensed from third reservoir 248 to the third spot location via nozzle 202, thereby forming third sample 256. After depositing of all sample spots, the substrate 214 can be subjected to thermal shock as described elsewhere herein, so as to form an array of multielement materials of different compositions on the substrate for subsequent screening.
In some embodiments, instead of premixing precursors, the precursors can be mixed from separate supplies according to desired compositions en route or just prior to dispensing via nozzle (e.g., on-the-fly mixing). For example,
Although
At stage 260, nozzle 202 can be aligned with a first spot location, for example, by moving nozzle 202 with respect to substrate 214, by moving substrate 214 with respect to the nozzle 202, or both. Flow from each reservoir 266-270 can be controlled via the respective valves 264a-264c to provide a desired first ratio of precursors (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the first spot location) to mixing conduit 262. The resulting first mixture of precursors can thus be dispensed to the first spot location via nozzle 202, thereby forming first sample 274. As shown at stage 278, the nozzle 202 can then be aligned with a second spot location, for example, by moving the nozzle 202 and/or the substrate 214. Flow from each reservoir 266-270 can be controlled via the respective valves 264a-264c to provide a desired second ratio of precursors (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the second spot location) to mixing conduit 262. The resulting second mixture of precursors can then be dispensed to the second spot location via nozzle 202, thereby forming second sample 276. Similarly, as shown at stage 282, the nozzle 202 can then be aligned with a third spot location, for example, by moving the nozzle 202 and/or the substrate 214. Flow from each reservoir 266-270 can be controlled via the respective valves 264a-264c to provide a desired third ratio of precursors (e.g., corresponding to a desired composition of the ultimate multielement material corresponding to the third spot location) to mixing conduit 262. The resulting third mixture of precursors can then be dispensed to the third spot location via nozzle 202, thereby forming third sample 280. After depositing of all sample spots, the substrate 214 can be subjected to thermal shock as described elsewhere herein, so as to form an array of multielement materials of different compositions on the substrate for subsequent screening.
Although the description of examples of
In some embodiments, a plurality of sample spots with different material compositions can be formed on a substrate according to a combinatorial approach. For example, combinatorial precursor mapping can be employed to provide a large number (e.g., at least 20, at least 50, at least 100, or at least 1000) of different compositions on the substrate for subsequent screening. In some embodiments, the combinatorial precursor mapping can include varying element compositions in a spatial arrangement (e.g., composition of one element varying in a stepwise gradual manner along one linear dimension).
The substrate can have any shape or configuration, but generally can have a least one exposed substantially-planar surface for deposition of sample spots of precursors thereon. Alternatively, in some embodiments, precursors can be deposited on an intervening material of the substrate (e.g., a metal electrode layer) or a deposition platform (e.g., carbon micro-disk) coupled to the substrate. In some embodiments, the substrate is formed of a material that can withstand exposure to the sintering temperature, for example, carbon, graphite, a refractory material (e.g., refractory metal), etc. Alternatively, in some embodiments where the precursors are sintered using deposition platforms and subsequently coupled to the substrate, the substrate is formed of a material that cannot withstand exposure the sintering temperature, for example, a metal (e.g., copper), a polymer, a composite, etc.
In some embodiments, the precursors can be deposited directly on a substrate surface, and the multielement materials formed by the precursors after thermal shock can thus be formed directly on and/or integrated with the substrate. For example,
In some embodiments, the precursors can be deposited indirectly on a substrate surface via one or more intermediate layers (e.g., a conductive layer, such as copper, for use in subsequent screening, for example, a common electrode). The multielement materials formed by the precursors after thermal shock can thus be formed on but spaced from a surface of the substrate. For example,
In some embodiments, one or more additional layers can be deposited directly or indirectly on the multielement materials, e.g., for using in subsequent screening, for example, as an individual electrical contact or electrode. For example,
In some embodiments, the precursors can be deposited on individual platforms which are subsequently coupled to the substrate, for example, after thermal shock treatment (e.g., when the substrate is formed of a material that may not otherwise survive exposure to the high temperature). For example,
In some embodiments, the plurality of sample spots can be spread over multiple separate substrates, for example, where the size of a single substrate is otherwise insufficient to accommodate all of the sample spots. For example,
Although
To convert deposited precursors into a substantially homogeneous solid mixture of multiple elements, the precursors can be subjected a thermal shock treatment comprising one or more high temperature pulses. For example,
After a delay t2, a second heating pulse 402 (which may be substantially identical to the first heating pulse 400) can be applied to the substrate. In some embodiments, the delay t2 can of sufficient duration to allow the substrate to be repositioned such that a next sample spot (or set of sample spots) thereon is disposed within the heating zone, for example, to allow conversion of precursors of the next sample spot. In some embodiments, the delay t2 can be less than a duration of the heating pulse period t1. Alternatively, the delay t2 can be substantially equal to or greater than the pulse duration t1.
In some embodiments, the heating device can be configured to sequentially heat sample spots on the substrate. For example,
Alternatively or additionally, in some embodiments, the heating device can be configured to heat multiple sample spots on the substrate simultaneously. For example,
Although
Although
The method 600 can proceed to process block 604, where sample spots with different intended material compositions can be mapped onto the substrate according to a combinatorial approach. At process block 606, a first sample spot on the substrate can be selected, and at process block 608, a first precursor can be deposited on the first sample spot according to the mapped material composition. In some embodiments, the deposition of process block 608 can be performed using a nozzle, for example, in a manner similar to that described above with respect to
If no further deposition of the first precursor is desired, the method 600 can proceed from decision block 610 to decision block 614, where it is determined if the deposited precursor should be subject to pre-sintering. For example, in some embodiments, after dispensing of one precursor on all desired spots of the substrate, the substrate can be subjected to thermal shock or at least to a thermal treatment at process block 616 prior to beginning dispensing of the next precursor. In some embodiments, such independent treatment of the precursors may help in mixing the elements of the deposited precursor with elements from subsequent precursor depositions. Otherwise, if pre-sintering is not desired, the method 600 can proceed from decision block 614 to decision block 616, where it is determined if additional precursors should be deposited. If so, the method 600 can proceed from decision block 618 to process block 620, where the next precursor is selected, and the deposition in process block 608 is repeated with the new precursor.
If no further deposition of any precursors is desired, the method 600 can proceed from decision block 618 to process block 622, where the deposited precursors are converted to multielement materials by subjecting the substrate to a thermal shock. In some embodiments, the subjecting of process block 622 can be performed using a heating device, for example, in a manner similar to that described above with respect to any of
The method 600 can proceed to process block 626, where a first multielement material of the substrate is selected for screening. At process block 628, the selected multielement material can be testing, for example, with respect to an electrical property, a chemical property, or an optical property. In some embodiments, the testing of process block 628 can be performed using an evaluation device, for example, in a manner similar to that described above with respect to any of
The method 600 can proceed to decision block 632, where it is determined if a next material should be selected for testing. If so, the method 600 can proceed to process block 634, where the next material is selected, and the testing in process block 628 is repeated for the selected next material. Alternatively, in some embodiments where the screening is performed in parallel (e.g., in a manner similar to that illustrated in
If no further testing is desired, the method 600 can proceed from decision block 632 to process block 636, where a material composition for use in a predetermined application can be determined. In some embodiments, the determination of process block 636 can be selection of one of the tested material samples that exhibit the best performance with respect to one or more predetermined criteria for the particular application, for example, a material that exhibits a highest electrocatalytic activity of those tested. Alternatively or additionally, the determination of process block 636 can act as feedback for a subsequent performance of method 600, for example, by providing a material composition or range thereof to serve as the basis for a new combinatorial mapping.
In
With reference to
A computing system may have additional features. For example, the computing environment 731 includes storage 761, one or more input devices 771, one or more output devices 781, and one or more communication connections 791. An interconnection mechanism (not shown) such as a bus, controller, or network interconnects the components of the computing environment 731. Typically, operating system software (not shown) provides an operating environment for other software executing in the computing environment 731, and coordinates activities of the components of the computing environment 731.
The tangible storage 761 may be removable or non-removable, and includes magnetic disks, magnetic tapes or cassettes, CD-ROMs, DVDs, or any other medium which can be used to store information in a non-transitory way, and which can be accessed within the computing environment 731. The storage 761 can store instructions for the software 733 implementing one or more innovations described herein.
The input device(s) 771 may be a touch input device such as a keyboard, mouse, pen, or trackball, a voice input device, a scanning device, or another device that provides input to the computing environment 731. The output device(s) 771 may be a display, printer, speaker, CD-writer, or another device that provides output from computing environment 731.
The communication connection(s) 791 enable communication over a communication medium to another computing entity. The communication medium conveys information such as computer-executable instructions, audio or video input or output, or other data in a modulated data signal. A modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media can use an electrical, optical, radio-frequency (RF), or another carrier.
Any of the disclosed methods can be implemented as computer-executable instructions stored on one or more computer-readable storage media (e.g., one or more optical media discs, volatile memory components (such as DRAM or SRAM), or non-volatile memory components (such as flash memory or hard drives)) and executed on a computer (e.g., any commercially available computer, including smart phones or other mobile devices that include computing hardware). The term computer-readable storage media does not include communication connections, such as signals and carrier waves. Any of the computer-executable instructions for implementing the disclosed techniques as well as any data created and used during implementation of the disclosed embodiments can be stored on one or more computer-readable storage media. The computer-executable instructions can be part of, for example, a dedicated software application or a software application that is accessed or downloaded via a web browser or other software application (such as a remote computing application). Such software can be executed, for example, on a single local computer (e.g., any suitable commercially available computer) or in a network environment (e.g., via the Internet, a wide-area network, a local-area network, a client-server network (such as a cloud computing network), or other such network) using one or more network computers.
For clarity, only certain selected aspects of the software-based implementations are described. Other details that are well known in the art are omitted. For example, it should be understood that the disclosed technology is not limited to any specific computer language or program. For instance, aspects of the disclosed technology can be implemented by software written in C++, Java, Perl, any other suitable programming language. Likewise, the disclosed technology is not limited to any particular computer or type of hardware. Certain details of suitable computers and hardware are well known and need not be set forth in detail in this disclosure.
It should also be well understood that any functionality described herein can be performed, at least in part, by one or more hardware logic components, instead of software. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Program-specific Integrated Circuits (ASICs), Program-specific Standard Products (AS SPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc.
Furthermore, any of the software-based embodiments (comprising, for example, computer-executable instructions for causing a computer to perform any of the disclosed methods) can be uploaded, downloaded, or remotely accessed through a suitable communication means. Such suitable communication means include, for example, the Internet, the World Wide Web, an intranet, software applications, cable (including fiber optic cable), magnetic communications, electromagnetic communications (including RF, microwave, and infrared communications), electronic communications, or other such communication means. In any of the above-described examples and embodiments, provision of a request (e.g., data request), indication (e.g., data signal), instruction (e.g., control signal), or any other communication between systems, components, devices, etc. can be by generation and transmission of an appropriate electrical signal by wired or wireless connections.
Conventionally, vapor-phase depositions can create a large number of samples using composition gradient. However, vapor-phase deposition requires sophisticated and expensive equipment with a limited choice of materials and substrates. In contrast, the high-throughput synthesis disclosed herein involves two relatively simple steps: (1) combinatorial composition design using metal precursors by formulation in solution phases; and (2) uniform MMNC synthesis by rapid thermal shock of a precursor-loaded carbon support, which drives the rapid precursor decomposition and alloy formation.
High-throughput synthesis of multimetallic nanoclusters (MMNCs) was achieved by combinatorial composition formulation in the solution phase on a surface-treated carbon support, followed by a rapid thermal-shock treatment. These compositionally-different MMNCs (with similar particle size and structure) were rapidly screened using scanning droplet cell analysis for the electrochemical oxygen reduction reaction (ORR), enabling efficient identification of the two best-performing catalysts. The combination of such high-throughput approaches can establish a facile and reliable pipeline to significantly accelerate discovery of MMNCs as advanced catalytic materials.
In particular, a series of MMNCs were fabricated, ranging from ternary materials (e.g., PtPdRh) to octonary materials (e.g., PtPdRhRuIrFeCoNi), by adding one element at a time. Precursors for each of the different composition MMNCs were loaded on a carbon nanofiber (CNF) substrate. To form the substrate, electrospun polyacrylonitrile nanofibers were stabilized in air at 533 K (260° C.) for 6 hours, and then carbonized at 1173 K (900° C.) for 2 hours in argon to form untreated CNFs. The CNF films were then further thermally activated at 1023 K (750° C.) for 2 hours in a CO2 atmosphere in order to create surface defects (e.g., a CO2-activated CNF (CA-CNF) substrate).
The individual metal salts or their hydrate forms were dissolved in ethanol at a concentration of 0.05 mol/L. Moreover, 10% (in volume) of 37% HCl was added to PdCl2 solution to complete dissolve PdCl2. The salt precursor solution was loaded onto the suspended CA-CNF film 804 via a print head 802 of a programmable 3D printer 800 (Fisnar F4200N), as shown in
The precursor-loaded carbon supports were then subjected to high-temperature thermal shock by electrically Joule heating to ˜1650 K for a duration of ˜500 ms. The samples were electrically connected in series for batch thermal shocking, as shown in
Transmission electron microscopy (TEM) images show the ultra-small and uniform distribution of PtPdRh, PtPdRhRuIr, and PtPdRhRuIrFeCoNi MMNCs, thereby confirming their similar size and dispersity despite the compositional differences. High-resolution high-angle annular dark-field (HAADF) images of the three MMNCs further confirm the similar size distributions, i.e., particles sizes for the PtPdRh, PtPdRhRuIr, and PtPdRhRuIrFeCoNi MMNCs of 3.3 nm±0.8 nm, 3.4 nm±0.7 nm, and 3.7 nm±1 nm, respectively.
As shown in
For conventional synthesis methods, incorporating more elements typically results in heterogeneous structures due to the immiscibility among different elements. In contrast, use of the disclosed thermal shock method can overcome immiscibility by creating liquid metal alloy states at high temperature, followed by rapid quenching to largely maintain the alloy mixing. In addition, the multielement materials could help drive the alloy formation by increasing entropy (ΔGmix↓=ΔHmix−T*ΔSmix↑), which provides kinetic constraints (e.g., severe lattice distortion and sluggish diffusion) such that alloy structures are discouraged from phase separation. The detailed structures of thermal-shock-fabricated MMNCs were fabricated using HAADF and EDS mapping. Low-magnification HAADF and EDS maps confirmed the ultrafine size and high-density dispersion of the nanoclusters, with each element roughly distributed throughout the fiber support without obvious elemental segregation. High-resolution HAADF and EDS images of the ternary, quinary, and octonary samples show particles of ˜3-4 nm in size, with each element being uniformly distributed within each nanocluster without clear phase separation or elemental segregation, indicating a solid-solution structure. Note that the final compositions in the MMNCs may be differ slightly from the designed/expected composition, for example, due to differences in metal vapor pressures at high temperatures. The thermal shock method enables alloying at high temperatures while limiting the duration of heating duration, thereby reducing metal losses.
Macroscopically, powder X-ray diffraction (XRD) profiles illustrate an overall face-centered-cubic (FCC) structure for ternary, quinary, and octonary MMNCs using the Rietveld refinement with a fitted lattice constant of 3.87, 3.82, and 3.76 Å, respectively, as shown in
From a high-throughput perspective, the overall MMNC synthesis protocol involves only printing precursor salts and rapid thermal shock, which are all physical processes that can be easily scaled up. Different metal salt solutions with desired recipes were mixed in the liquid phase. In particular, the combinatorial compositions were designed and formulated in the solution phase using individual precursor solutions with a concentration of 0.05 mol/L. The mixture solutions were then deposited on respective CA-CNF disks (˜0.3-inch diameter) with a loading of 100 μL/cm2 (i.e., ˜5 μmol/cm2). These CA-CNF disks were then attached in a pattern (e.g., regular layout) onto a common surface of a copper plate (e.g., copper-foil wrapped silicon wafer) via conductive silver paste. Then, rapid radiative heating (non-direct contact) was used for the MMNC synthesis by positioning a high-temperature heating source above a subset of the samples (e.g., spaced by about ˜0.5 cm) and subjected to repeated thermal shock (e.g., heating to 2000 K (1727° C.) for a duration of ˜0.5 s, for 3 times). Then the heating element was moved to the next subset of samples until all the samples on the substrate had been heated. A piece of graphitic carbon paper was used as the radiative heating source driven by Joule-heating in an Ar-filled glovebox.
Using this method, a plate containing a library of 88 samples, including (1) MMNCs in the PtPdRhRuIrFeCoNi compositional space for ORR, and (2) MMNCs in the IrRuAuPdMnFeCoNi space for oxygen evolution reaction (OER), with each composition having 2 samples for cross-validation. The single-phase structure and uniform size distributions of selected MMNCs were also verified. The PtPdRhRuIrFeCoNi compositional space was synthesized and screened using scanning droplet cell electrochemistry, with two promising catalysts quickly identified and further verified in a rotating disk setup. High-throughput electrochemistry was performed to rapidly screen for promising MMNC catalysts. Scanning droplet cell analysis (e.g., as shown in
The electrochemical tests were performed at room temperature. After moving to a new sample location, the first 30 seconds was used to stabilize the contact between the droplet volume and the selected sample. The electrochemical tests included two 20 mV/s cyclic voltammetry sweeps followed by one 5 mV/s cyclic voltammetry sweep between 1.1 V and 0.45 V versus reversible hydrogen electrode (RHE). A capillary Ag/AgCl electrode reference electrode was flushed with fresh saturated KCl solution every 30 minutes to avoid possible contamination. Because the magnitude of the measured current was around 10−4 A, the ohm drop was neglectable. However, the IrRu-based MMNCs samples for OER were found to have apparent corrosion current at high potential, which can obscure the performance and cause uncertainty. Therefore, the following discussion focuses on the PtPd-based compositions for ORR.
As shown in
To verify the high performance of the two optimized catalysts (PtPdRhNi and PtPdFeCoNi), electrochemical analysis was performed using a rotating disk electrode (RDE) setup, in particular a Pine Bipotentiostat RDE4 with a glassy carbon (GC) rotating disk electrode (RDE, 0.196 cm2) and a rotating ring-disk electrode (RRDE, 0.247 cm2, collection coefficient 0.37). The two MMNCs (PtPdRhNi and PtPdFeCoNi) and the Pt control were synthesized on CA-CNF with a loading of ˜10 wt % using the thermal shock synthesis approach. These samples were then prepared into inks for the measurement in 1.0 M KOH at room temperature (22±1° C.).
In addition, both MMNC catalysts exhibit increased peak current densities by about a factor of two as compared to that of Pt. In
Any of the features illustrated or described herein, for example, with respect to
In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only examples and should not be taken as limiting the scope of the disclosed technology. Rather, the scope is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.
The present application claims the benefit of U.S. Provisional Application No. 63/158,645, filed Mar. 9, 2021, entitled “Combinatorial Synthesis and High Throughput Screening of Multielement Nanoparticles and Functional Bulk Materials,” which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63158645 | Mar 2021 | US |
