High-flux ultrahigh-temperature high-pressure hydrothermal synthesis device and hydrothermal synthesis method

Abstract

The invention discloses a high-flux ultrahigh-temperature high-pressure hydrothermal synthesis device and a hydrothermal synthesis method. The hydrothermal synthesis device comprises: an autoclave main body; wherein the autoclave main body is internally provided with a porous core, and the porous core is internally provided with a plurality of hole sites; the multiple hole sites can contain and support 20-100 independent suspension type lining pipes at the same time. And the suspension type lining pipe is used as an independent micro reaction cavity. Through high-throughput design (20-100 samples are treated at a time), the influence of different components, different mineralizing agents, different concentrations, different additives and the like on the ultrahigh-temperature and high-pressure hydrothermal synthesis product can be explored in parallel and systematically, and the discovery speed of a new material is greatly increased; the core concepts of high-throughput calculation, high-throughput preparation and high-throughput characterization of material gene engineering are perfectly met.

Description

Technical Field

[0001] The present invention relates to the field of material science and chemical synthesis technology, and more particularly to a high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device and a hydrothermal synthesis method. Background Art

[0002] Hydrothermal synthesis, a method for chemical reactions and material preparation in high-temperature, high-pressure water or solvent media, has played a vital role in single crystal growth, functional ceramics, nanomaterials, and composite materials for nearly a century. Its unique reaction environment can alter the reactivity of reactants, enabling the realization of specific crystal forms, metastable phases, or new compounds that are difficult to achieve using solid-phase reactions. It also facilitates the growth of high-quality crystals and the control of product morphology and particle size.

[0003] Traditional hydrothermal methods can be roughly divided into low temperature (<100°C), medium temperature (100-300°C) and high temperature (>300°C) according to the temperature. However, facing the urgent need to accelerate the research and development of new materials in the "Materials Genetic Engineering" program, existing hydrothermal technologies have obvious limitations. On the one hand, although the traditional medium-temperature hydrothermal method is relatively mature and can achieve a certain throughput, its temperature and pressure range is limited, and it is impossible to explore new phases and new materials that may be formed under higher energy conditions. On the other hand, existing high-temperature and high-pressure hydrothermal studies (>300°C) are often limited to single sample synthesis or small-scale experiments, using expensive precious metal liners (such as platinum, gold) or special alloy autoclaves, and lacking high-throughput design. The experimental efficiency is low and it is difficult to meet the requirements of rapid screening of the vast component space and process parameter space required by materials genetic engineering.

[0004] In particular, the exploration range will be expanded to the ultra-high temperature region of 400-600℃, which corresponds to higher pressure (usually far exceeding the critical pressure of water 22.1MPa, up to tens or even hundreds of MPa) and more intense reaction conditions, which puts higher demands on the equipment's temperature resistance, pressure resistance, corrosion resistance and operational safety, and also provides opportunities for the synthesis of materials with completely new structures and properties. At present, there is a lack of an effective and reliable hydrothermal synthesis platform that can simultaneously achieve high-throughput screening (dozens or hundreds of comparative experiments at a time) under ultra-high temperature and high pressure conditions of 400-600℃. The lack of such a platform has seriously restricted the efficiency of new material exploration under extreme hydrothermal conditions and is a technical bottleneck that needs to be urgently addressed in the development of materials genetic engineering methodology.

[0005] In the prior art, patent CN115961352A discloses an apparatus that applies external gas pressure to multiple vacuum-sealed quartz crucibles in a silicon carbide furnace to conduct high-temperature solid-phase or gas-phase reactions. This differs fundamentally from the present invention: the present invention employs a specific hydrothermal synthesis, creating a high-temperature, high-pressure aqueous solution environment within a liner tube and balancing pressure with an external liquid; whereas patent CN115961352A conducts a non-hydrothermal reaction within a vacuum crucible, utilizing an external inert gas to balance physical pressure. The two devices are fundamentally different in their reaction principles, core internal structures, sample container environments, and pressure balancing mechanisms. Therefore, the present invention is not an obvious improvement over patent CN115961352A.

[0006] On the other hand, patent CN112064117A describes a method for hydrothermally growing a specific crystal (lithium niobate) using a single bushing tube, and mentions external pressure balancing of a suspended single bushing tube. However, this technology focuses on optimizing the growth conditions of a single tube, and its core structure is a baffle inside the tube. The core of the present invention is to integrate dozens to hundreds of independent micro-bushing tubes through a porous core to achieve high-throughput parallel screening, especially under ultra-high temperature extreme conditions of 400-600°C. Simply scaling up the single-tube concept of CN112064117A cannot produce the integrated system designed by the present invention for the high-throughput exploration needs of material genetic engineering under specific extreme conditions.

[0007] In summary, the inventiveness of this invention lies in its unique integrated design of "porous core + numerous independent bushings + external liquid pressure balance," specifically designed to achieve high-throughput hydrothermal synthesis and screening under extreme conditions of ultra-high temperature and high pressure, 400-600°C. This platform, built to accelerate the exploration of genetic engineering of materials, differs significantly from existing technologies in terms of reaction principles and implementation methods (compared to CN115961352A), as well as in terms of flux scale, design objectives, and application scenarios (compared to CN112064117A). It is not a simple combination of existing technologies or an obvious application extension. Summary of the Invention

[0008] In view of this, the present invention provides a high-throughput ultra-high temperature and high pressure hydrothermal synthesis device and a corresponding hydrothermal synthesis method for material genetic engineering, aiming to significantly improve the efficiency of exploring new materials under extreme conditions of ultra-high temperature and high pressure of 400-600℃.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device comprises: an autoclave body;

[0011] The autoclave body is provided with a porous core (or sample holder, reaction tube bundle support), and the porous core is provided with a plurality of holes; and independent suspended liner tubes are provided in the holes;

[0012] The suspended liner tube serves as an independent micro reaction chamber.

[0013] In the present invention, the autoclave body is designed to withstand the high pressure (eg, up to 100 MPa or higher) generated when operating in the temperature range of 400-600°C.

[0014] Preferably, the inner diameter of the autoclave body is 20-42 mm.

[0015] Preferably, the effective volume of the autoclave body is 150-1200 ml.

[0016] Preferably, the material of the suspended bushing tube is a quartz tube, a silver tube or a gold tube, and the material is selected according to experimental requirements to adapt to the chemical environment under ultra-high temperature and avoid pollution.

[0017] Another object of the present invention is to provide a high-throughput ultra-high temperature and high pressure hydrothermal synthesis method, comprising the following steps:

[0018] S1 Prepare the bushing:

[0019] According to the material genetic engineering experimental design, different raw material components (solids, solutions, etc.) and corresponding mineralizers (water or other solvents, etc.) are respectively loaded into one end of multiple suspended bushings according to the designed filling degree, and then the open ends of the suspended bushings are sealed;

[0020] S2 loading autoclave:

[0021] The sealed suspension bushings containing different reaction systems are numbered and placed in sequence into the corresponding holes of the porous core in the autoclave;

[0022] S3 pressure balance medium filling:

[0023] In the gap between the outside of the liner tube and the inner wall of the autoclave, calculate and add an appropriate amount of pressure balancing medium based on the filling degree of the inside of the liner tube and the target operating temperature;

[0024] S4 Sealing and Heating:

[0025] Seal the autoclave to ensure it can operate safely at the target ultra-high temperature and corresponding high pressure, and place the sealed autoclave in the matching heating furnace;

[0026] S5 programmed temperature synthesis:

[0027] Set the heating program to raise the temperature to the target constant temperature at a controllable heating rate and maintain it for a period of time to perform the hydrothermal synthesis reaction;

[0028] S6 cooling and sampling:

[0029] After the reaction is completed, the autoclave is cooled to a safe temperature according to the set cooling program, and then naturally cooled to room temperature;

[0030] S7 product collection and analysis:

[0031] The autoclave was opened, and all the suspended liner tubes were taken out in turn. The synthetic products in each liner tube were observed, separated, cleaned, and dried. XRD, SEM, EDS and other analytical techniques were used to perform phase identification, morphology characterization, and composition analysis, thereby obtaining a large amount of parallel experimental data to serve the database construction and new material screening of material genetic engineering.

[0032] Preferably, the pressure balancing medium in step S3 is an inert liquid.

[0033] More preferably, the inert liquid is deionized water or distilled water.

[0034] Preferably, the target ultrahigh temperature in step S4 is 400-600°C.

[0035] Preferably, the safety temperature in step S6 is 100°C.

[0036] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. Greatly expanded the exploration space: The operating temperature of hydrothermal synthesis is raised to the ultra-high temperature region of 400-600℃, and matched with the corresponding high-pressure conditions, opening up a new material synthesis parameter window that is difficult to achieve with traditional hydrothermal methods.

[0038] 2. Significantly improved screening efficiency: Through high-throughput design (processing 20-100 samples at a time), it is possible to systematically explore the effects of different components, different mineralizers, different concentrations, and different additives on ultra-high temperature and high-pressure hydrothermal synthesis products in parallel, greatly accelerating the discovery of new materials and perfectly matching the core concepts of high-throughput calculation, high-throughput preparation, and high-throughput characterization in materials genetic engineering.

[0039] 3. Enhanced experimental controllability and flexibility: Each independent sleeve is a separate reaction system, eliminating cross-contamination and facilitating precise control of each experimental condition. Sleeves made of various materials, such as quartz, silver, and gold, can be adapted to the needs of different chemical reaction systems, and the tube itself can even participate in or catalyze the reaction.

[0040] 4. Provides powerful tools for material genetic engineering: The present invention provides a set of platform technologies that can perform high-throughput material synthesis and screening under extreme conditions, providing key experimental support for the exploration and discovery of new functional materials (such as new nonlinear optical crystals, piezoelectric ferroelectric materials, catalysts, thermoelectric materials, etc.) based on material genetic engineering strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0042] Figure 1 2 are photos of different configurations of high-throughput porous core accessories suitable for use in the present invention.

[0043] Figure 2 This is a photo of the quartz liner tube used in the present invention.

[0044] Figure 3 The figure is a typical flow chart for conducting high-throughput ultra-high temperature and high pressure hydrothermal synthesis experiments using the apparatus and method of the present invention.

[0045] Figure 4 XRD patterns of Lu2O3 under different process conditions.

[0046] Figure 5 These are photos of Lu2O3 crystals obtained under different experimental conditions (left: experiment number 8, right: experiment number 9).

[0047] Figure 6 XRD patterns of Sc2O3 under different process conditions.

[0048] Figure 7 These are crystal photos of Sc2O3 obtained under different experimental conditions (left: experiment number 14, right: experiment number 15).

[0049] Figure 8 This is a photo of centimeter-scale YOOH crystals obtained under experimental condition 21. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] All embodiments of the present invention are carried out in an autoclave adapted to ultra-high temperature and high pressure conditions. The autoclave has an inner diameter of about 30 mm, an effective volume of about 400 ml, and is equipped with a porous core inside, which can accommodate at least 30 liner tubes.

[0052] Example 1: High-throughput exploration of the synthesis of rare earth sesquioxide crystal materials (gold tube)

[0053] 1. Raw Material Preparation: This example involved 21 independent experiments designed to explore the synthesis patterns of various rare earth sesquioxide crystalline materials under supercritical hydrothermal conditions. Experimental variables included the selection of different oxides as precursor materials. High-purity alkali solutions of varying concentrations were used as mineralizers, including potassium hydroxide (KOH) solutions (ranging from 4M to 20M), potassium carbonate (K2CO3) solutions (ranging from 2M to 4M), cesium hydroxide (CsOH) solutions (12M), and mixed mineralizers (e.g., a combination of 20M KOH and 0.5M KNO3). Optimization was achieved by systematically varying key parameters, including the type of rare earth element, the type and concentration of the mineralizer, the reaction temperature (set between 500°C and 650°C), and the fill level (controlled between 40% and 65%). pH variations were generally directly correlated with the type and concentration of the selected mineralizer.

[0054] 2. Tube Filling and Sealing: Mix the raw materials (solid powder, solution) for each experimental design in the predetermined proportions and load them into high-purity gold tubes (60 mm long, 5 mm outer diameter, 0.3 mm wall thickness), each sealed at one end. Gold tubes are chosen for their excellent chemical inertness under strong alkalinity, high temperature, and high pressure. Each tube is filled with a predetermined amount of mineralizer solution, with a calculated fill rate of approximately 40%-65%. High-precision laser welding or electron beam welding is used to seal the open ends of the gold tubes under an inert atmosphere to ensure airtightness.

[0055] 3. Autoclave loading: 21 leak-proof and well-sealed gold tubes are numbered and placed in order into the corresponding holes of the porous core inside the autoclave. A certain volume of deionized water is filled between the liner tube and the autoclave wall as a pressure balance medium.

[0056] 4. Synthesis: Carefully seal the autoclave. Place it in a resistance furnace capable of rapid and uniform heating. Set the temperature program to rise to the target temperature. Maintain the reaction at this extreme temperature (water is in a supercritical state and the system pressure exceeds 100 MPa) for three days to promote the formation of a specific crystalline phase of the high-melting-point, difficult-to-crystallize rare earth sesquioxide.

[0057] 5. Cooling and sampling: After the reaction is completed, set the program to cool down to 100°C. After the temperature and internal pressure of the autoclave drop to an absolutely safe operating range, slowly release the pressure according to the regulations and open the autoclave, and carefully remove all gold tubes.

[0058] 6. Analysis: Cut open the gold tube and completely transfer out the solid product and solution inside. Wash the solid product repeatedly with ultrapure water and anhydrous ethanol to remove residual ions, and then dry it at low temperature. The products of 21 different experimental conditions were characterized in detail in terms of phase and morphology. By comparing and analyzing the results of 21 groups of experiments, the effects of different synthesis conditions on the crystal phase, morphology, etc. of rare earth sesquioxides were evaluated, and the optimal process parameters for preparing the target rare earth sesquioxide materials were screened out. Table 1 provides the specific parameters and experimental results of the 21 groups of experimental conditions. Figure 4-8 XRD patterns and crystal photos of samples obtained under different experimental conditions.

[0059] Table 1 High-throughput exploration of rare earth sesquioxide material synthesis conditions

[0060]

[0061]

[0062] Example 2: High-throughput exploration of new oxides in the Bi-Te-O system (quartz tube)

[0063] 1. Raw material preparation: For the Bi-Te-O ternary system, 35 different combinations of Bi source (such as Bi2O3, Bi(NO3)3·5H2O), Te source (such as TeO2, H6TeO6) molar ratios and mineralizers (water, NaOH solution, H3PO4 solution, etc.) were designed.

[0064] 2. Tube Filling and Sealing: Weigh each set of raw materials and place them into a high-quality quartz tube with an outer diameter of 6mm, a wall thickness of 1mm, and a length of 70mm, sealed at one end. Fill each tube with 0.3ml of the corresponding mineralizer solution, calculating a fill rate of approximately 25-30%. Use specialized equipment to securely seal the open end of the quartz tube.

[0065] 3. Loading the Autoclave: Number and place 35 sealed quartz tubes into the porous core of the autoclave. Fill the space between the lining tube and the autoclave wall with deionized water (approximately 30% of the volume) as a pressure balancing medium.

[0066] 4. Synthesis: Seal the autoclave and place it in a resistance furnace. Set the temperature program to 500°C at a rate of 5°C / minute. Maintain the temperature at 500°C for 72 hours, during which time the pressure in the autoclave reaches approximately 80 MPa.

[0067] 5. Cooling and sampling: After the constant temperature is completed, cool to 100℃ at a rate of 2℃ / hour, then turn off the power and cool naturally to room temperature. Safely open the autoclave and remove the quartz tube.

[0068] 6. Analysis: Carefully open each quartz tube, collect the solid product inside, rinse with deionized water and ethanol, and dry. Perform X-ray powder diffraction (XRD) phase analysis on each sample, and observe the morphology of valuable samples using scanning electron microscopy (SEM).

[0069] Example 3: High-throughput screening of Ag-based catalyst precursor preparation conditions (silver tube)

[0070] 1. Raw material preparation: Design 30 sets of experiments to explore the reaction behavior of different precursors (such as AgNO3, AgOAc), reducing agents (such as ethylene glycol, sodium citrate), protective agents (such as PVP, oleylamine), and solvents (water, ethylene glycol, mixed solvents) under ultrahigh temperature solvothermal conditions, aiming to synthesize Ag-based nanostructures with specific morphologies.

[0071] 1. Tube Filling and Sealing: Weigh each set of raw materials and place them into a high-purity silver tube with an outer diameter of 8 mm, a wall thickness of 2 mm, and a length of 80 mm, sealed at one end. Fill each tube with 0.6 ml of the corresponding solution, for a calculated fill rate of approximately 35%. Securely seal the open end of the silver tube using argon arc welding or laser welding.

[0072] 2. Autoclave Loading: Number 50 sealed silver tubes and place them into the porous core of the autoclave. Fill the space between the liner tube and the autoclave wall with deionized water (approximately 38% by volume) as a pressure balancing medium.

[0073] 3. Synthesis: Seal the autoclave and place it in a heating furnace. Set the program to increase the temperature to 450°C at a rate of 10°C / minute. Maintain the temperature at 450°C for 24 hours, during which time the pressure in the autoclave is expected to reach approximately 60 MPa.

[0074] 4. Cooling and sampling: After the constant temperature is completed, quickly cool the temperature (10℃ / hour) to 100℃, and then cool naturally. Open the autoclave safely and remove the silver tube.

[0075] 5. Analysis: Open the silver tube, collect the product, wash and dry it. Analyze the product's phase, morphology, and size distribution using XRD, SEM, TEM, and other methods to identify the optimal synthesis conditions for the precursor or nanostructure with the desired catalytic activity.

[0076] Example 4: Changing vessel size and throughput

[0077] Using an autoclave with an inner diameter of 42 mm and an effective volume of 1000 ml, a porous core was designed and fabricated to accommodate 100 liner tubes with an outer diameter of 6 mm. The experimental protocol of Example 1 was repeated, but 100 exploratory experiments were performed simultaneously on the Bi-Te-O system. The operating temperature was set to 550°C, and the pressure balance medium filling level was adjusted to match the target pressure (approximately 90 MPa). 100 data points were obtained in a single experiment, significantly improving screening throughput.

[0078] Other embodiments can be designed similarly, by changing the temperature, pressure (adjusted by filling degree), time, raw material system, liner pipe material combination, etc., to reflect the high flexibility and wide applicability of the method of the present invention.

[0079] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0080] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device, characterized in that: include: Autoclave body; The autoclave body is provided with a porous core, and a plurality of holes are provided in the porous core; independent suspended bushings are provided in the holes; The suspended liner tube serves as an independent micro reaction chamber.

2. A high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device according to claim 1, characterized in that: The inner diameter of the autoclave body is 20-42 mm.

3. A high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device according to claim 1, characterized in that: The effective volume of the autoclave body is 150-1200 ml.

4. A high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device according to claim 1, characterized in that: The material of the suspended bushing tube is a quartz tube, a silver tube or a gold tube.

5. A high-throughput ultra-high temperature and high pressure hydrothermal synthesis method, characterized in that: The high-throughput ultra-high temperature and high-pressure hydrothermal synthesis device according to any one of claims 1 to 4 comprises the following steps: S1 Prepare the bushing: According to the material genetic engineering experimental design, different raw material components and corresponding mineralizers are respectively loaded into one end of multiple suspended bushing tubes according to the designed filling degree, and then the open ends of the suspended bushing tubes are sealed; S2 loading autoclave: The sealed suspension bushings containing different reaction systems are numbered and placed in sequence into the corresponding holes of the porous core in the autoclave; S3 pressure balance medium filling: In the gap between the outside of the liner tube and the inner wall of the autoclave, calculate and add an appropriate amount of pressure balancing medium based on the filling degree of the inside of the liner tube and the target operating temperature; S4 Sealing and Heating: Seal the autoclave to ensure it can operate safely at the target ultra-high temperature and corresponding high pressure, and place the sealed autoclave in the matching heating furnace; S5 programmed temperature synthesis: Set the heating program to raise the temperature to the target constant temperature at a controllable heating rate and maintain it for a period of time to perform the hydrothermal synthesis reaction; S6 cooling and sampling: After the reaction is completed, the autoclave is cooled to a safe temperature according to the set cooling program, and then naturally cooled to room temperature; S7 product collection and analysis: The autoclave is opened, and all the suspended liner tubes are taken out in turn. The synthetic products in each liner tube are observed, separated, cleaned, and dried, and analytical technology is used to perform phase identification, morphology characterization, and composition analysis, thereby obtaining a large amount of parallel experimental data to serve the database construction and new material screening of material genetic engineering.

6. A high-throughput ultra-high temperature and high pressure hydrothermal synthesis method according to claim 5, characterized in that: The pressure balancing medium in step S3 is an inert liquid.

7. A high-throughput ultra-high temperature and high pressure hydrothermal synthesis method according to claim 5, characterized in that: The target ultrahigh temperature in step S4 is 400-600°C.

8. A high-throughput ultra-high temperature and high pressure hydrothermal synthesis method according to claim 5, characterized in that: The safety temperature in step S6 is 100°C.

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