Ni-loaded photothermal catalyst based on MOF-derived heterojunction and molten salt method, and preparation method and application thereof

Abstract

The application discloses a MOF-derived heterojunction composite molten salt loaded Ni photothermal catalyst and a preparation method and application thereof, and belongs to the technical field of new energy catalytic materials. The preparation method comprises the following steps: firstly, Zr-MOF is synthesized by using a zirconium source and an organic ligand, a titanium source is added for partial substitution, and a Zr / Ti-MOF precursor is constructed; then, the Zr / Ti-MOF precursor is subjected to temperature-controlled calcination to obtain a MOF-derived ZrO2 / TiO2 heterojunction composite carrier; finally, the carrier is mixed and ground with a nickel precursor and a LiCl-KCl molten salt system, calcination is carried out in an inert atmosphere, and the target product, a Ni / ZrO2 / TiO2 photothermal catalyst, is obtained through washing and drying. The application combines the unique structural advantages of the MOF derivative and the promotion of the molten salt system, realizes the highly uniform dispersion of the active center Ni and the strong metal-support interaction, and the catalyst can realize efficient and stable photothermal synergistic catalysis of the methanol aqueous-phase reforming for hydrogen production at 210 DEG C and under alkaline conditions, so that the energy consumption of the reaction is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of catalytic materials technology, and more specifically, relates to a Ni / ZrO2 / TiO2 photothermal catalyst, its preparation method, and its application. Background Technology

[0002] Hydrogen, as a clean, high-energy-density, and pollution-free renewable energy source, holds great promise for replacing traditional fossil fuels in the future, with significant application potential in fields such as chemical engineering, metallurgy, and fuel cells. However, storing and transporting hydrogen at ambient temperature and pressure is extremely difficult. Methanol (CH3OH), recognized as one of the cleanest liquid fuels, is widely available and easy to store and transport; therefore, in-situ hydrogen production through methanol reforming is considered an ideal way to solve the hydrogen supply problem.

[0003] Currently, the traditional methanol aqueous reforming (APR) technology for hydrogen production is relatively mature. However, this process is typically thermodynamically limited, requiring high temperatures and pressures, which not only leads to significant energy consumption but also substantially increases equipment costs. Furthermore, at temperatures above 250°C, the reforming reaction is prone to side reactions that produce carbon monoxide (CO). Even trace amounts of CO can easily poison and deactivate the electrode catalysts in proton exchange membrane fuel cells (PEMFCs). Regarding catalysts, commercially available copper-based catalysts, while low in cost, are prone to metal particle sintering, carbon deposition, and active site poisoning during high-temperature reactions, leading to rapid catalyst deactivation. While noble metal catalysts offer excellent performance, their high cost limits their large-scale industrial application. Therefore, exploring low-cost catalytic systems that can achieve efficient methanol liquid-phase reforming for hydrogen production at lower temperatures is of great significance.

[0004] In recent years, solar-driven photothermal synergistic catalysis technology has provided a new approach for achieving green and low-carbon hydrogen production. This technology utilizes electron-hole pairs generated by photoexcitation or electrons generated by localized surface plasmon resonance to effectively reduce the apparent activation energy of the catalytic reaction, and combines this with thermal energy to accelerate reaction kinetics, thereby achieving efficient methanol reforming at significantly reduced temperatures.

[0005] However, single photothermal catalytic systems still face many challenges in practical applications. On the one hand, conventional preparation methods (such as impregnation and co-precipitation) often fail to achieve highly uniform dispersion of non-noble metal active components (such as transition metals like Ni) on the support surface, resulting in large metal particle sizes and weak interactions between the metal and the support, which severely limits the separation efficiency of photogenerated charges and catalytic activity. On the other hand, designing and constructing a composite catalytic material that possesses both broad-spectrum absorption capabilities and the ability to effectively activate reaction substrate molecules remains a critical technological bottleneck that urgently needs to be overcome in this field. Therefore, there is an urgent need to develop a novel catalyst synthesis strategy and highly efficient photothermal catalytic materials to meet the demand for low-energy consumption and high-stability methanol-water-phase reforming hydrogen production under mild conditions. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the current thermocatalytic methanol liquid-phase reforming for hydrogen production, such as high energy consumption, low catalytic efficiency of single catalysts, and poor stability. The present invention provides a Ni / ZrO2 / TiO2 photothermal catalyst that combines photocatalysis and thermocatalysis, using light energy and thermal energy to provide the heat required for the reaction, thereby improving catalytic efficiency.

[0007] The purpose of this invention is to provide a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst.

[0008] Another objective of this invention is to provide the application of Ni / ZrO2 / TiO2 photothermal catalysts in the photothermal synergistic catalytic reforming of methanol to produce hydrogen.

[0009] Therefore, the first technical solution provided by this invention is as follows:

[0010] S1. A zirconium source, organic ligand, and modifier are mixed in an organic solvent and subjected to a solvothermal reaction to obtain the precursor Zr-MOF;

[0011] S2. Disperse the Zr-MOF precursor obtained in step S1 with a titanium source in an organic solvent and carry out a solvothermal reaction to obtain titanium-substituted Zr / Ti-MOF;

[0012] S3. The Zr / Ti-MOF obtained in step S2 is calcined under controlled temperature to obtain a ZrO2 / TiO2 heterojunction composite support;

[0013] S4. The nickel source, molten salt system and the ZrO2 / TiO2 heterojunction composite support obtained in step S3 are mixed and thoroughly ground, calcined under an inert atmosphere, and then washed and dried to obtain the MOF-derived heterojunction composite molten salt-supported Ni photothermal catalyst.

[0014] Further, in step S1, the zirconium source is zirconium tetrachloride (ZrCl4); the organic ligand is 2-aminoterephthalic acid (NH2-BDC); the regulator is acetic acid; and the organic solvent is N,N-dimethylformamide (DMF).

[0015] Further, in step S1, the molar ratio of zirconium tetrachloride to 2-aminoterephthalic acid is 1:1.

[0016] Furthermore, in step S2, the titanium source is tetrabutyl titanate.

[0017] Preferably, in steps S1 and S2, the temperature of the solvothermal reaction is 100–150°C and the reaction time is 12–36 h.

[0018] Preferably, in step S3, the heating rate of the temperature-controlled calcination is 1-5℃ / min, the calcination temperature is 400-550℃, and the holding time is 1-4h.

[0019] Further, in step S4, the nickel source is nickel chloride hexahydrate (NiCl2·6H2O); the molten salt system is a mixture of lithium chloride (LiCl) and potassium chloride (KCl).

[0020] Further, in step S4, the mass ratio of the nickel chloride hexahydrate, lithium chloride, potassium chloride and the ZrO2 / TiO2 heterojunction composite carrier is (0.01~0.05):1:1:1.

[0021] Preferably, in step S4, before heating and calcining, the tubular furnace is evacuated and continuously purged with inert gas; the heating rate of the calcination is 5-10℃ / min, the calcination temperature is 400-600℃, and the holding time is 1-4h.

[0022] Furthermore, in step S4, the washing process uses deionized water, and the drying temperature is 60–100°C.

[0023] The present invention also provides a MOF-derived heterojunction composite molten salt supported Ni photothermal catalyst prepared by the above preparation method. The photothermal catalyst is Ni / ZrO2 / TiO2, wherein the active component Ni is supported on a MOF-derived ZrO2 / TiO2 heterojunction composite support.

[0024] This invention also provides a method for producing hydrogen from methanol via aqueous reforming. In an alkaline aqueous system, the above-mentioned MOF-derived heterojunction composite molten salt-supported Ni / ZrO2 / TiO2 photothermal catalyst, methanol, and water are added and reacted at 150-210°C and 1-3 MPa for 30-120 minutes under light irradiation.

[0025] Furthermore, in the above-mentioned method for producing hydrogen from methanol via aqueous reforming, the alkali is one or more of potassium hydroxide and sodium hydroxide; the mass ratio of the MOF-derived heterojunction composite molten salt method for supporting Ni photothermal catalyst, methanol, water and alkali is 0.005:6.4:3.6:0.5.

[0026] The present invention has the following beneficial effects:

[0027] 1. This invention first constructs a Zr-MOF with high specific surface area and regular pore structure, and then uses a titanium source for partial coordination substitution to finely control the composition of the metal nodes. After controlled-temperature calcination, a ZrO2 / TiO2 heterojunction composite support with a tightly contacted interface is successfully derived in situ, effectively broadening the spectral absorption range and forming a highly efficient interfacial charge transport channel.

[0028] 2. When loading the active component, this invention cleverly combines a LiCl-KCl low-melting-point molten salt system. During calcination, the liquid molten salt medium not only effectively inhibits the aggregation and sintering of non-noble metal Ni species and promotes highly uniform dispersion of active sites, but also significantly enhances the electronic interaction between Ni and the heterojunction support.

[0029] 3. Thanks to the aforementioned synergistic effect, the catalyst of this invention can achieve highly efficient hydrogen production from methanol liquid-phase reforming at temperatures far lower than those of traditional thermocatalysis (e.g., 210°C). This not only significantly reduces the energy consumption and equipment costs of industrial hydrogen production, but also effectively suppresses CO poisoning and carbon deposition deactivation problems caused by side reactions at high temperatures, demonstrating broad prospects for industrial application. Attached Figure Description

[0030] Figure 1 The XRD patterns of the Zr-MOF, Zr / Ti-MOF, ZrO2 / TiO2 and Ni / ZrO2 / TiO2 photothermal catalysts prepared in Example 1 of this invention are shown.

[0031] Figure 2 Transmission electron microscope images of (a) Zr-MOF, (b) Zr / Ti-MOF, (c) ZrO2 / TiO2 and (d) Ni / ZrO2 / TiO2 prepared for Example 1 of the present invention;

[0032] Figure 3 High-magnification transmission electron microscopy (HRTEM) image of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1 of this invention;

[0033] Figure 4 The image shows a comparison of the photothermal / thermal catalytic performance of the Zr-MOF, Zr / Ti-MOF, Ni / ZrO2, and Ni / ZrO2 / TiO2 photothermal catalysts prepared in Example 1 of this invention, respectively, for hydrogen production from methanol liquid-phase reforming. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0035] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0036] In the following examples, some of the raw materials used to prepare the Ni / ZrO2 / TiO2 photothermal catalyst were:

[0037] Organic ligand: 2-aminoterephthalic acid (NH2-BDC);

[0038] Metal salt: Zirconium chloride (ZrCl4);

[0039] Regulator: Acetic acid;

[0040] Polar organic solvent: N,N-dimethylformamide (DMF).

[0041] Example 1

[0042] This embodiment provides a Ni / ZrO2 / TiO2 photothermal catalyst, which is prepared through the following steps:

[0043] S1: Preparation of Zr-MOF

[0044] 0.9322 g (4 mmol) of ZrCl4 was dissolved in 220 mL of DMF solution by ultrasonication and magnetically stirred for 20 min. Then, 0.7246 g (4 mmol) of NH2-BDC was added, stirred for 10 min, and ultrasonicated for another 10 min. Next, 20 mL of acetic acid was added to the mixture, and the mixture was stirred for 20 min to form a precursor solution. The resulting precursor solution was transferred to a high-pressure reactor lined with polytetrafluoroethylene (PTFE) and heated at 120 °C for 24 h. After natural cooling to room temperature, the solid product was collected and washed three times sequentially with DMF and methanol solutions. Finally, the obtained solid was dried under vacuum at 60 °C for 12 h to obtain Zr-MOF.

[0045] S2: Preparation of Zr / Ti-MOF

[0046] The Zr-MOF (1 g) prepared in step S1 was stirred and ultrasonically dispersed in 25 mL of DMF, followed by the addition of 1 mL of tetrabutyl titanate. The mixture was then transferred to a polytetrafluoroethylene-lined high-pressure reactor, which was sealed and heated at 120 °C for 24 h. After natural cooling to room temperature, the solid product was collected and washed three times with DMF and methanol solutions, respectively. Finally, the obtained solid was vacuum dried at 60 °C for 12 h to obtain Zr / Ti-MOF with Ti partially substituted SBU-Zr.

[0047] S3: Preparation of ZrO2 / TiO2 heterojunction composite support

[0048] The Zr / Ti-MOF (1g) prepared in step S2 was placed in a crucible and then placed in a muffle furnace. The temperature was increased to 450℃ at a heating rate of 2℃ / min and held for 2 hours. After naturally cooling to room temperature, the resulting solid product was collected to obtain the ZrO2 / TiO2 heterojunction material.

[0049] S4: Preparation of Ni / ZrO2 / TiO2 photothermal catalyst

[0050] First, NiCl2·6H2O (20 mg), LiCl (1 g), KCl (1 g), and the ZrO2 / TiO2 (1 g) prepared in step S3 were mixed and ground in an agate mortar for 10 minutes to obtain a homogeneous mixture. This mixture was transferred to a crucible and placed in a tube furnace. The tube furnace was evacuated three times and purged with N2 for 15 minutes to ensure complete removal of residual air. Then, the mixture was heated to 500 °C at a heating rate of 8 °C / min and held at this temperature for 2 hours. After cooling to room temperature, the sample was removed from the tube furnace and collected in centrifuge tubes. It was washed three times with deionized water to remove salts (LiCl and KCl) from the sample. Finally, the sample was dried overnight in an oven at 80 °C to obtain the target product, the Ni / ZrO2 / TiO2 photothermal catalyst.

[0051] Example 2

[0052] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that the zirconium source in step S1 is zirconium oxychloride octahydrate ZrOCl2·8H2O.

[0053] For other parameters and operations, please refer to Example 1.

[0054] Example 3

[0055] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that the precursor solution reacts at 120°C for 12 hours in step S1 within a polytetrafluoroethylene liner.

[0056] For other parameters and operations, please refer to Example 1.

[0057] Example 4

[0058] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that in step S1, the reaction temperature of the precursor solution in the polytetrafluoroethylene liner is 100°C, and the reaction time is 36 hours.

[0059] For other parameters and operations, please refer to Example 1.

[0060] Example 5

[0061] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Embodiment 1 is that the reaction temperature in the high-pressure reactor in step S2 is 150°C and the reaction time is 12 hours.

[0062] For other parameters and operations, please refer to Example 1.

[0063] Example 6

[0064] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Embodiment 1 is that the reaction temperature in the high-pressure reactor in step S2 is 100°C and the reaction time is 36 hours.

[0065] For other parameters and operations, please refer to Example 1.

[0066] Example 7

[0067] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that in step S3, the temperature is increased to 550°C at a heating rate of 5°C / min and held for 1 hour.

[0068] For other parameters and operations, please refer to Example 1.

[0069] Example 8

[0070] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that in step S4, NiCl2·6H2O (10mg), LiCl (1g), KCl (1g) are used, and in step S3, ZrO2 / TiO2 (1g) is prepared.

[0071] For other parameters and operations, please refer to Example 1.

[0072] Example 9

[0073] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that in step S4, NiCl2·6H2O (50mg), LiCl (1g), and KCl (1g) are used, and in step S3, ZrO2 / TiO2 (1g) is prepared.

[0074] For other parameters and operations, please refer to Example 1.

[0075] Example 10

[0076] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that in step S4, the temperature is increased to 600°C at a heating rate of 5°C / min and held at this temperature for 1 hour.

[0077] For other parameters and operations, please refer to Example 1.

[0078] Example 11

[0079] This embodiment provides a method for preparing a Ni / ZrO2 / TiO2 photothermal catalyst. The difference from Example 1 is that in step S4, the temperature is increased to 400°C at a heating rate of 10°C / min and maintained at this temperature for 4 hours.

[0080] For other parameters and operations, please refer to Example 1.

[0081] Comparative Example 1

[0082] This comparative example provides a method for preparing a Ni / ZrO2 photothermal catalyst, the specific steps of which are as follows:

[0083] S1: Preparation of Zr-MOF: Same as step 1 in Example 1.

[0084] S2: Preparation of ZrO2 support: The prepared unsubstituted titanium Zr-MOF (1g) was placed in a crucible and then placed in a muffle furnace. The temperature was increased to 450℃ at a heating rate of 2℃ / min and held for 2 hours. After natural cooling to room temperature, the resulting solid product was collected to obtain a common ZrO2 semiconductor material support.

[0085] S3: Preparation of Ni / ZrO2 photothermal catalyst: The ZrO2 / TiO2 support in step S4 of Example 1 was replaced with an equal mass (1g) of pure ZrO2 prepared in step S2. The remaining process steps and conditions, such as grinding, nitrogen atmosphere purging pretreatment, calcination heating program, temperature control and heat preservation, washing and drying, remained completely unchanged, and the target product Ni / ZrO2 material was finally obtained.

[0086] Characterization test

[0087] The Ni / ZrO2 / TiO2 photothermal catalyst described in Example 1 was characterized and its photothermal catalytic performance was tested.

[0088] The crystal structure of the Zr-MOF, Zr / Ti-MOF, ZrO2 / TiO2, and Ni / ZrO2 / TiO2 photothermal catalysts described in Example 1 was analyzed using X-ray diffraction, and the XRD patterns of the obtained samples were measured. The results are as follows: Figure 1 As shown, the Zr-MOF, Zr / Ti-MOF, ZrO2 / TiO2, and Ni / ZrO2 / TiO2 photothermal catalysts all exhibit good crystallinity. Characteristic peaks belonging to Zr-MOF can be observed in the XRD diffraction patterns of Zr-MOF and Zr / Ti-MOF, indicating that Zr-MOF has been successfully prepared. The XRD diffraction patterns of ZrO2 / TiO2 and Ni / ZrO2 / TiO2 are basically consistent, indicating that after Ni is supported on the ZrO2 / TiO2 support, no obvious defects or changes occur in the structure, and the catalyst has been successfully prepared. The XRD patterns of the Ni / ZrO2 / TiO2 photothermal catalysts prepared in Examples 2-11 are basically consistent with those in Example 1.

[0089] The scanning electron microscope (SEM) images of the obtained samples are shown in the following figures. Figure 2 As shown, transmission electron microscopy (TEM) images of (a) Zr-MOF, (b) Zr / Ti-MOF, (c) ZrO2 / TiO2, and (d) Ni / ZrO2 / TiO2 are presented. The morphology of Zr / Ti-MOF, where some SBUs-Zr is replaced by Ti, is completely preserved. ZrO2 / TiO2 derived from Zr / Ti-MOF by calcination also largely retains the octahedral morphology of the MOF precursor. TEM images of the Ni / ZrO2 / TiO2 photothermal catalysts in Examples 2-11 are essentially consistent with those in Example 1, all showing an octahedral structure.

[0090] The high-magnification transmission electron microscopy (HRTEM) spectra of the Ni / ZrO2 / TiO2 photothermal catalyst were measured, and the results are as follows: Figure 3 As shown, two sets of periodic fringes with different lattice spacings can be clearly identified: one set with a lattice spacing of 0.296 nm and the other with a lattice spacing of 0.352 nm. According to the standard crystallography database, the 0.296 nm lattice fringes are highly consistent with the (101) plane spacing of tetragonal ZrO2, while the 0.352 nm lattice fringes are consistent with the (101) plane spacing of anatase TiO2. These two sets of lattice fringes are arranged continuously and regularly in the image, and they converge directionally in a specific region to form a continuous interface, which is the heterojunction interface formed by ZrO2 and TiO2. The transmission electron microscopy (TEM) spectra of the photothermal catalysts prepared in Examples 2-11 are basically consistent with those in Example 1.

[0091] Photothermal catalytic methanol liquid-phase reforming to produce hydrogen was tested using Zr-MOF, Zr / Ti-MOF, ZrO2 / TiO2, and Ni / ZrO2 / TiO2 photothermal catalysts.

[0092] Photothermal catalytic methanol liquid-phase reforming for hydrogen production is carried out in a photothermal reactor and heated by a furnace equipped with a magnetic stirrer and external lighting.

[0093] Application Example 1

[0094] 0.5 g of KOH was dissolved in 10 g of methanol-water solution, and the solution was sonicated until dissolved. The solution was then transferred to a photothermal reactor, and 5 mg of the Ni / ZrO2 / TiO2 photothermal catalyst described in Example 1 was added. The reactor was then pressurized with N2 to 2 MPa and repeatedly purged three times to ensure complete removal of air. The reactor was irradiated for 80 minutes at 210 °C and 2 MPa using a 300 W Xe lamp (CEL-HXF300-T3 and / or CEL-HXUV300-T3). After the reaction, the gas inside the photothermal reactor was collected using a gas bag and analyzed by GC (GC9790PLUS) to determine the amount of hydrogen produced.

[0095] The methanol-water solution is prepared by mixing methanol and water in a mass ratio of 6.4:3.6.

[0096] Application Example 2-10

[0097] The Ni / ZrO2 / TiO2 photothermal catalysts prepared in Examples 2-11 were used respectively. The amounts of other reaction raw materials, reaction conditions, and test operation steps were the same as in Application Example 1. The corresponding relationships are shown in Table 1.

[0098] Table 1

[0099] Application Example 2 <![CDATA[The Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 2]]> Application Example 3 <![CDATA[Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 3]]> Application Example 4 <![CDATA[Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 4]]> Application Example 5 <![CDATA[Ni / ZrO₂ / TiO₂ photothermal catalyst prepared in Example 5]]> Application Example 6 <![CDATA[Ni / ZrO₂ / TiO₂ photothermal catalyst prepared in Example 6]]> Application Example 7 <![CDATA[Ni / ZrO₂ / TiO₂ photothermal catalyst prepared in Example 7]]> Application Example 8 <![CDATA[Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 8]]> Application Example 9 <![CDATA[The Ni / ZrO₂ / TiO₂ photothermal catalyst prepared in Example 9]]> Application Example 10 <![CDATA[Ni / ZrO₂ / TiO₂ photothermal catalyst prepared in Example 10]]>

[0100] Application Example 11-17

[0101] Photothermal catalytic methanol liquid-phase reforming to produce hydrogen was carried out at different reaction temperatures. The amounts of other reaction raw materials, reaction conditions, and test operation steps were the same as in Application Example 1. The corresponding relationships are shown in Table 2.

[0102] Table 2

[0103] Application Example 11 150℃ Application Example 12 160℃ Application Example 13 170℃ Application Example 14 180℃ Application Example 15 190℃ Application Example 16 200℃ Application Example 17 210℃

[0104] Comparative Application Example 1

[0105] The Ni / ZrO2 photothermal catalyst prepared in equal amounts as in Comparative Example 1 was used instead of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1. The amounts of other reactants, reaction conditions, and test procedures were the same as in Application Example 1.

[0106] Comparative Application Example 2

[0107] The Zr-MOF prepared in step S1 of Example 1 was used in place of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1. The amounts of other reactants, reaction conditions, and test procedures were the same as in Application Example 1.

[0108] Comparative Application Example 3

[0109] The Zr / Ti-MOF prepared in step S2 of Example 1 was used in place of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1. The amounts of other reactants, reaction conditions, and test procedures were the same as in Application Example 1.

[0110] Comparative Application Example 4

[0111] The Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1 was used without Xe lamp irradiation and the reaction was carried out only under thermal catalytic conditions at 210℃. The amounts of other reactants, reaction pressure, reaction time, and test operation steps were the same as in Application Example 1.

[0112] Comparative Application Example 5

[0113] The Ni / ZrO2 photothermal catalyst prepared in equal amounts as in Comparative Example 1 was used instead of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1. Xe lamp irradiation was not performed, and the reaction was carried out only under thermal catalytic conditions at 210°C. The amounts of other reaction raw materials, reaction pressure, reaction time, and test operation steps were the same as in Application Example 1.

[0114] Comparative Application Example 6

[0115] The Zr-MOF prepared in step S1 of Example 1 was used instead of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1. Xe lamp irradiation was not performed, and the reaction was carried out only under thermal catalytic conditions at 210℃. The amounts of other reaction raw materials, reaction pressure, reaction time, and test operation steps were the same as in Application Example 1.

[0116] Comparative Application Example 7

[0117] The Zr / Ti-MOF prepared in step S2 of Example 1 was used instead of the Ni / ZrO2 / TiO2 photothermal catalyst prepared in Example 1. Xe lamp irradiation was not performed, and the reaction was carried out only under thermal catalytic conditions at 210℃. The amounts of other reactants, reaction pressure, reaction time, and test operation steps were the same as in Application Example 1.

[0118] Compare and contrast examples 8-9

[0119] Photothermal catalytic methanol liquid-phase reforming to produce hydrogen was carried out at different reaction temperatures. The amounts of other reactants, reaction conditions, and test procedures were the same as in Application Example 1. The corresponding relationships are shown in Table 3.

[0120] Table 3

[0121] Comparative Application Example 8 90℃ Comparative Application Example 9 120℃

[0122] For the results of the photothermal / thermocatalytic performance tests of Zr-MOF, Zr / Ti-MOF, Ni / ZrO2, and Ni / ZrO2 / TiO2 photothermal catalysts for methanol liquid-phase reforming to hydrogen production, as determined by Application Examples 1, 11-17, and Comparative Application Examples 1-9, please refer to the following: Figure 4 ,in, Figure 4 Figure a shows the hydrogen production performance of different catalysts under light irradiation at 210℃. Figure 4 Figure b shows the hydrogen production performance of the Ni / ZrO2 / TiO2 photothermal catalyst at different temperatures under both with and without light irradiation. It can be seen that the photothermal catalytic hydrogen production rate of Zr-MOF is significantly higher than that of thermocatalytic hydrogen production. Under the synergistic effect of photothermal action, the Ni / ZrO2 / TiO2 photothermal catalyst exhibits a more significant improvement in hydrogen production performance, reaching 7.5 times its thermocatalytic hydrogen production rate and nearly 5.6 times that of Zr-MOF.

[0123] like Figure 4 b. Within the reaction temperature range of 90 ~ 210 ℃, the H2 production rate under both light and dark conditions is positively correlated with the reaction temperature. Furthermore, under photothermal conditions, the hydrogen production rate of Ni / ZrO2 / TiO2 is several times higher than that under thermocatalytic conditions. Under photothermal catalytic conditions, the Ni / ZrO2 / TiO2 photothermal catalyst can also achieve a hydrogen production rate of 355.6 at 90 ℃. The rate of H2 production is significantly higher under photothermal conditions. However, under thermocatalytic conditions, H2 can only be effectively detected in gas chromatography when the reaction temperature exceeds 150℃. Benefiting from the advantages of photothermal synergistic catalysis, the hydrogen production rate of the Ni / ZrO2 / TiO2 photothermal catalyst under photothermal conditions is significantly higher than that under thermocatalytic conditions. This indicates that the synergistic effect of photocatalysis and thermocatalysis can accelerate the conversion of adsorbates on the catalyst surface. Utilizing light energy to promote catalyst activation or in-situ reduction of active centers, and utilizing thermal energy to provide the heat required for the reaction, the two interact synergistically to improve the efficiency of methanol liquid-phase reforming for hydrogen production and lower the required reaction temperature. Thanks to the type II heterojunction formed by the ZrO2 / TiO2 heterojunction, the charge separation efficiency is further improved, promoting redox reactions such as CH3OH / H2O reforming.

[0124] The photothermal catalytic performance results of the Ni / ZrO2 / TiO2 photothermal catalysts in Examples 2-11 are basically consistent with those in Example 1. The prepared catalysts all utilize light energy to promote the activation of the catalyst or the in-situ reduction of the active center, and utilize thermal energy to provide the heat required for the reaction. The two interact to synergistically improve the efficiency of methanol aqueous reforming to produce hydrogen.

[0125] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a Ni photothermal catalyst supported by a MOF-derived heterojunction composite molten salt method, characterized in that, The steps are as follows: S1. A zirconium source, organic ligand, and modifier are mixed in an organic solvent and subjected to a solvothermal reaction to obtain the precursor Zr-MOF; S2. Disperse the Zr-MOF precursor obtained in step S1 with a titanium source in an organic solvent and carry out a solvothermal reaction to obtain a partially titanium-substituted Zr / Ti-MOF. S3. The Zr / Ti-MOF obtained in step S2 is calcined under controlled temperature to obtain a ZrO2 / TiO2 heterojunction composite support; S4. Mix the nickel source, molten salt system and the ZrO2 / TiO2 heterojunction composite support obtained in step S3 and grind them thoroughly. Calcinate the mixture under an inert atmosphere, and after washing and drying, obtain the Ni / ZrO2 / TiO2 photothermal catalyst.

2. The method for preparing a Ni photothermal catalyst supported by a MOF-derived heterojunction composite molten salt method according to claim 1, characterized in that, In step S1, the zirconium source is zirconium tetrachloride; The organic ligand is 2-aminoterephthalic acid; The regulator is acetic acid; The organic solvent is N,N-dimethylformamide; In step S2, the titanium source is tetrabutyl titanate.

3. The method for preparing a Ni photothermal catalyst supported by a MOF-derived heterojunction composite molten salt method according to claim 1, characterized in that, In steps S1 and S2, the temperature of the solvothermal reaction is 100–150°C, and the reaction time is 12–36 h.

4. The method for preparing a Ni photothermal catalyst supported by a MOF-derived heterojunction composite molten salt method according to claim 1, characterized in that, In step S3, the heating rate of the temperature-controlled calcination is 1-5℃ / min, the calcination temperature is 400-550℃, and the holding time is 1-4h.

5. The method for preparing a Ni photothermal catalyst supported by a MOF-derived heterojunction composite molten salt method according to claim 1, characterized in that, In step S4, the nickel source is nickel chloride hexahydrate; The molten salt system is a mixture of lithium chloride and potassium chloride; The mass ratio of the nickel chloride hexahydrate, lithium chloride, potassium chloride and the ZrO2 / TiO2 heterojunction composite carrier is (0.01~0.05):1:1:

1.

6. The method for preparing a Ni photothermal catalyst supported by a MOF-derived heterojunction composite molten salt method according to claim 1, characterized in that, In step S4, the heating rate of calcination is 5-10℃ / min, the calcination temperature is 400-600℃, and the holding time is 1-4h.

7. A Ni photothermal catalyst supported by MOF-derived heterojunction composite molten salt method, characterized in that, It is prepared by the method of MOF-derived heterojunction composite molten salt method for supporting Ni photothermal catalyst as described in any one of claims 1 to 6.

8. The application of the MOF-derived heterojunction composite molten salt method supported Ni photothermal catalyst as described in claim 7 in photothermal synergistic catalytic methanol aqueous reforming for hydrogen production.

9. A method for producing hydrogen through methanol aqueous phase reforming, characterized in that, In an alkaline aqueous system, the MOF-derived heterojunction composite molten salt-supported Ni photothermal catalyst, methanol, and water described in claim 7 are added, and the reaction is carried out under light irradiation at 150-210°C and 1-3 MPa for 30-120 minutes.

10. The method for producing hydrogen from methanol via aqueous reforming according to claim 9, characterized in that, The alkali is one or more of potassium hydroxide and sodium hydroxide; the mass ratio of the MOF-derived heterojunction composite molten salt method supported Ni photothermal catalyst, methanol, water and alkali is 0.005:6.4:3.6:0.5.

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