A high-activity pt-based MOFs derived metal oxide material, a preparation method and application thereof

Abstract

The application discloses a kind of high-activity Pt-based MOFs derived metal oxide materials and its preparation method and application, belong to catalytic material field.Preparation method includes H3BTC is dissolved in NaOH solution, slowly drop into FeCl2 aqueous solution, low-speed stirring is followed by high-speed centrifugation, in ammonium fluoride aqueous solution reaction, cooling to room temperature, centrifugation, washing, drying, the obtained MIL-100 (Fe) precursor is high-temperature carbonization under O2 condition, and Fe2O3-M carrier is obtained;H2PtCl6.6H2O and Fe2O3-M carrier are dissolved in deionized water, stirring is uniformly mixed, slowly drop NaBH4 solution, continue stirring, high-speed centrifugation and washing, drying, grinding, and Pt / Fe2O3-M catalyst is obtained, part retains original MOFs stereoscopic structure, enhances the dispersity of Pt nanoparticle on surface, is used to catalyze glycerol to generate glyceric acid, completes effective adsorption and activation, and improves catalytic performance.

Description

Technical Field

[0001] This invention belongs to the field of catalyst materials, specifically relating to a highly active Pt-based MOFs-derived metal oxide material, its preparation method, and its application. Background Technology

[0002] There are two main systems for the oxidative conversion of glycerol: alkaline catalytic systems and alkaline-free catalytic systems. The alkaline catalytic system activates the primary hydroxyl bond of glycerol with OH- in the alkaline system, which oxidizes it to glyceric acid. For example, Yu et al. developed a Pt-Au supported Mn-based MOF derivative for the catalytic oxidation of glycerol to glyceric acid in an alkaline system (X.-M.Yu, Y. Ke, X. Wang, H. Liu, H. Yuan, MOFs-Derived MnxOyCz SupportedBimetallicAu-Pt Catalyst for the Catalytic Oxidation of Glycerol to GlycericAcid, Chemistry of Materials 36 (3) (2024) 1737-1752.). The alkali-free catalytic system activates the primary hydroxyl bonds of glycerol through reactive oxygen species such as O* and OH* generated from O2 and H2O, thereby oxidizing them to glyceric acid (M. Zhang, R. Nie, L. Wang, J. Shi, W. Du, Z. Hou, Selective oxidation of glycerol overcarbon nanoofibers supported Pt catalysts in a base-free aqueous solution, Catalysis Communications, 59 (2015) 5-9. and X. Huang, Z. Long, Z. Wang, S. Li, P. Zhang, Y. Leng, Mesoporous silicon-carbon composites: Novel supports of platinum nanoparticles for highly efficient selective oxidation of glycerol, Chemical Engineering Journal, 470 (2023), 144037.).

[0003] However, existing catalytic systems for the oxidation of glycerol still have the following drawbacks: In alkaline catalytic systems, the addition of liquid alkali easily corrodes equipment, increases costs, and makes it difficult to separate the liquid alkali from the product glyceric acid. In alkali-free catalytic systems, the lack of OH- activation of the primary hydroxyl group of glycerol under alkali-free conditions results in low activity for most catalysts in the conversion of glycerol; moreover, active oxygen under alkali-free conditions mostly relies on the hydrolysis of O2 and H2O to form, while most catalysts have limited adsorption and hydrolysis capabilities for O2 under normal pressure, thus limiting the activation efficiency of glycerol. Summary of the Invention

[0004] To address the problems of existing alkaline catalytic systems that easily corrode equipment, increase costs, and make product separation difficult, as well as the poor O2 adsorption and hydrolysis effects and insufficient glycerol oxidation efficiency of most catalysts in alkali-free catalytic systems, the main objective of this invention is to provide a highly active Pt-based MOFs-derived metal oxide material. As a Pt-based MOFs-derived supported catalyst rich in oxygen vacancies, it can adsorb more O2 molecules in an alkali-free system without relying on a high-pressure environment to participate in hydrolysis and generate active oxygen species, thereby oxidizing the primary hydroxyl group of glycerol to generate glyceric acid.

[0005] Another objective of this invention is to provide a method for preparing the highly active Pt-based MOFs-derived metal oxide material, which is simple to synthesize and easy to scale up for production.

[0006] Another object of the present invention is to provide the application of the highly active Pt-based MOFs-derived metal oxide material in the catalytic production of glycerol into glyceric acid.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing highly active Pt-based MOFs-derived metal oxide materials, comprising the following steps:

[0009] Step S1: Preparation of MIL-100(Fe) precursor. The process includes: H3BTC is dissolved in NaOH solution, FeCl2 aqueous solution is slowly added dropwise to form a mixed solution, stirred at low speed and then centrifuged at high speed. The resulting solid sample is placed in ammonium fluoride aqueous solution and reacted in a high-pressure reactor at 60-80 ℃ for 2-4 h. After cooling to room temperature, it is separated by centrifugation. The resulting solid is washed with deionized water and ethanol and dried at 80 ℃ to form MIL-100(Fe) precursor.

[0010] Step S2: Preparation of Fe2O3-M support, the process includes: placing the MIL-100(Fe) precursor in a tube furnace and heating at 10°C / min. -1The heating rate was increased to 700-900℃, and the temperature was carbonized at 700-900℃ for 1-2 h under O2 conditions to obtain Fe2O3-M support;

[0011] Step S3: Pt / Fe2O3-M catalyst is synthesized by impregnation method. H2PtCl6·6H2O is reduced to PtNPs using NaBH4. The process includes: dissolving H2PtCl6·6H2O and Fe2O3-M support in deionized water, stirring and mixing, slowly adding NaBH4 solution dropwise to the mixed solution, continuing stirring, centrifuging and washing at 8000 rpm, drying at 60℃ overnight, and grinding the resulting solid into powder to obtain Pt / Fe2O3-M catalyst, which is a highly active Pt-based MOFs-derived metal oxide material.

[0012] Preferably, in step S1, the preparation process of the MIL-100 (Fe) precursor includes: dissolving 0.5603 g H3BTC in 10 mL of 1 mol / L NaOH solution, then slowly adding 40 mL of 0.1 M FeCl2 aqueous solution dropwise using a dropper to form a mixed solution, stirring at 450 rpm for 24 h, then centrifuging at 5500 rpm for 3 min to separate the solid sample, placing it in 40 mL of 40 mM ammonium fluoride aqueous solution, reacting in a 50 mL high-pressure reactor at 70 ℃ for 3 h, cooling to room temperature, centrifuging to separate the solid, washing the obtained solid three times with deionized water and ethanol, and then drying at 80 ℃ to form the MIL-100 (Fe) precursor.

[0013] Preferably, in step S2, the preparation process of the Fe2O3-M support includes: placing the MIL-100(Fe) precursor in a tube furnace and heating at 10°C / min. -1 The heating rate was increased to 800℃, and the mixture was carbonized at 800℃ for 1 hour under O2 conditions to obtain the Fe2O3-M support.

[0014] Preferably, in step S3, the loading of Pt is 3.00 wt%.

[0015] Preferably, in step S3, the Pt / Fe2O3-M catalyst is synthesized by impregnation method. The process includes: dissolving 0.0398 g H2PtCl6·6H2O and 0.5 g Fe2O3-M support powder in 50 mL deionized water and stirring for 5 h; then slowly adding 5 mL 0.1 M NaBH4 solution to the mixed solution and stirring for another 1 h; then centrifuging and washing the resulting solution at 8000 rpm and drying it overnight in an oven at 60 ℃; and grinding the resulting solid into powder to obtain the Pt / Fe2O3-M catalyst, which is a highly active Pt-based MOFs-derived metal oxide material.

[0016] In a second aspect, the present invention provides a highly active Pt-based MOFs-derived metal oxide material, which is prepared by a method for preparing the highly active Pt-based MOFs-derived metal oxide material.

[0017] A third aspect of the present invention provides the application of the highly active Pt-based MOFs-derived metal oxide material in the catalytic production of glycerol into glyceric acid.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] I. This invention develops a novel high-oxygen vacancy MOFs-derived material. Unlike traditional metal oxides, this material partially retains the original three-dimensional structure of MOFs, enhances the dispersion of Pt nanoparticles on the surface, and facilitates better diffusion and reaction of glycerol molecules during the reaction process.

[0020] Second, the high oxygen vacancy content in this invention can adsorb more oxygen molecules in the reaction system to participate in hydrolysis and form more active oxygen species, so that glycerol molecules can complete effective adsorption and activation under alkaline conditions and without relying on high pressure, thereby improving catalytic performance. Attached Figure Description

[0021] Figure 1 The image shows the XRD pattern of the MIL-100 (Fe) precursor in this example.

[0022] Figure 2 The XRD patterns of (a) Pt / Fe2O3-M, Fe2O3-M, Pt / Fe2O3 and Fe2O3 in the examples are shown; and the XRD patterns of Pt / Fe2O3-M, Pt / Fe2O3 and Pt / C are shown.

[0023] Figure 3 The N2 adsorption-desorption isotherms and pore size distribution diagrams for Pt / Fe2O3-M, Fe2O3-M, Pt / Fe2O3, and Fe2O3 in the examples are shown.

[0024] Figure 4The images shown are SEM images of (a) Pt / Fe2O3-M; (b) Pt / Fe2O3; (c) Fe2O3-M; and (d) Fe2O3 in the examples.

[0025] Figure 5 The images shown are: (a) TEM image of Pt / Fe2O3-M; (b, d) high-resolution transmission electron microscopy (HRTEM) images of Pt / Fe2O3-M; (c) particle size distribution of Pt / Fe2O3-M; (ei) energy scattering spectrum (EDS) of Pt / Fe2O3-M; and (j) TEM image of Pt / Fe2O3-M.

[0026] Figure 6 The XPS spectra of (a) O 1s orbitals of Pt / Fe2O3-M and (b) Pt / Fe2O3 in the examples; (c) XPS spectra of Fe 2p orbitals of Pt / Fe2O3-M and Fe2O3-M; (d) XPS spectra of Fe 2p orbitals of Pt / Fe2O3 and Fe2O3; the Pt4f XPS spectra of (e) Pt 4f orbitals of Pt / Fe2O3-M and Pt / C; and (f) XPS spectra of Pt 4f orbitals of Pt / Fe2O3-M and Pt / Fe2O3.

[0027] Figure 7 The EPR spectra of Pt / Fe2O3-M and Pt / Fe2O3 in the examples are shown.

[0028] Figure 8 This is a schematic diagram of the synthesis process of the Pt / Fe2O3-M catalyst in the examples.

[0029] Figure 9 The HPLC chromatogram analysis of the reaction solution in the examples is shown.

[0030] Figure 10 The images show the HPLC chromatograms of different products in the examples. Detailed Implementation

[0031] To more fully understand and demonstrate the technical solutions, objectives, and advantages of the present invention, the technical effects produced by the present invention will be further described in detail and completely below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. It should be noted that other embodiments obtained by those skilled in the art without departing from the concept of the present invention are all within the protection scope of the present invention.

[0032] Example 1

[0033] The preparation process of Pt-based MOFs-derived supported materials rich in oxygen vacancies is as follows:

[0034] Step 1: Preparation of MIL-100 (Fe) precursor

[0035] H3BTC (0.5603 g) was dissolved in 10 mL of 1 mol / L NaOH solution, and then 40 mL of FeCl2 (0.1 M) aqueous solution was slowly added dropwise using a dropper to form a mixed solution. The mixture was stirred at 450 rpm for 24 h. The solution was then centrifuged at 5500 rpm for 3 min to obtain a solid sample. Subsequently, the solid sample was placed in 40 mL of 40 mM ammonium fluoride aqueous solution and reacted in a 50 mL high-pressure reactor at 70 °C for 3 h. After cooling to room temperature, the solid was centrifuged, washed three times with deionized water and ethanol, and then dried in an oven at 80 °C to form the MIL-100 (Fe) precursor.

[0036] Step 2: Preparation of Fe2O3-M metal oxide support

[0037] The MIL-100 (Fe) precursor was carbonized in a tube furnace. The solid was carbonized at 800 °C for 1 h under O2 conditions, with a heating rate of 10 °C / min to reach the desired temperature. -1 Fe2O3-M support was obtained.

[0038] Step 3: Preparation of Pt / Fe2O3-M catalyst

[0039] Pt / Fe2O3-M catalyst was synthesized by impregnation method with a Pt loading of 3.00 wt%. H2PtCl6·6H2O was reduced to Pt NPs using NaBH4. 0.0398 g of H2PtCl6·6H2O and 0.5 g of Fe2O3-M solid powder were dissolved in 50 mL of deionized water and stirred for 5 h. Then, 5 mL of 0.1 M NaBH4 solution was slowly added dropwise to the mixture, and stirring was continued for another 1 h. The resulting solution was then centrifuged at 8000 rpm, washed, and dried overnight in an oven at 60 °C. The resulting solid was ground into powder and designated as Pt / Fe2O3-M.

[0040] Comparative Example 1

[0041] Fe₂O₃ was synthesized at room temperature using a simple chemical deposition method. 2.177 g of FeCl₂·4H₂O and 0.88 g of NaOH were dissolved in 100 mL of deionized water. The mixture was then stirred at room temperature until complete precipitation. The solid sample was separated by centrifugation, washed three times with deionized water, and finally dried in an oven at 80 °C to obtain Fe(OH)₃ solid precipitate. Finally, the precursor was carbonized in a tube furnace at 800 °C for 1 h under O₂ conditions, with a heating rate of 10 °C / min to reach the desired temperature. -1 Fe2O3 support was obtained.

[0042] Example 1

[0043] The Pt-based MOFs-derived supported material rich in oxygen vacancies prepared in Example 1 was used as a catalyst in the glycerol oxidation reaction under alkaline and atmospheric pressure conditions. The operation process is as follows:

[0044] 5 mL of 0.1 M glycerol solution and 40 mg of catalyst were added to a 50 mL quartz flask and placed in an oil bath at 60 °C. The glycerol oxidation reaction was carried out using oxygen supplied to the flask as the oxygen source. The stirring rate was maintained at 500 r / min throughout the process, and the reaction was continued for 6 h. After the reaction was complete, the reaction solution was cooled to room temperature, and then the catalyst and product were filtered. The product solution was collected for analysis.

[0045] Glycerol conversion was analyzed using gas chromatography-flame ionization detector (GC-FID). An HP-INNOWAX column (30 m × 0.25 mm × 0.25 μm) was used with nitrogen as the carrier gas at a flow rate of 1 mL / min. The injection port temperature was 250 °C, the detector temperature was 300 °C, and the split ratio was 100:1. The column oven temperature was initially set at 40 °C, increased to 80 °C at a rate of 5 °C / min after 1 min, and then increased to 250 °C at a rate of 10 °C / min and held for 5 min. Product selectivity was determined using a Sykam S-501 high-performance liquid chromatography (HPLC) system with a Bio-Rad Aminex HPX-87 H column and a UV-Vis dual-wavelength detector (S6852, wavelength set to 210 nm). The mobile phase was 5 mM sulfuric acid (H₂SO₄) at a flow rate of 0.6 mL / min, the column temperature was 50 °C, and the injection volume was 10 μL. Quantitative analysis was performed using the external standard method, and accurate quantification was achieved by plotting a calibration curve.

[0046] The conversion rate of GLY and the selectivity of different catalysts for each product were calculated using the following formula:

[0047] GLY conversion rate (%) = (initial glycerol concentration - remaining glycerol concentration) / initial glycerol concentration × 100%;

[0048] Product selectivity (%) = Post-reaction product concentration × Number of carbon atoms in the product ( / Initial glycerol concentration - Remaining glycerol concentration) × 3 × 100%;

[0049] Yield (%) = Product selectivity × Glycerol conversion;

[0050] Analysis showed that the Pt / Fe2O3-M catalyst exhibited excellent selective oxidation performance of glycerol (GLY) to glyceric acid (GLA) under alkali-free conditions and atmospheric pressure, achieving a GLY conversion rate of 80% and a GLA selectivity of 75% under the conditions of 60 °C, 6 h, 0.04 g catalyst, and atmospheric pressure.

[0051] like Figure 1 As shown, the obvious characteristic peaks of MIL-100(Fe) in the X-ray diffraction pattern (XRD) indicate that the MIL-100(Fe) precursor was successfully synthesized.

[0052] Figure 2 (a) shows that distinct diffraction peaks appear at 2θ angles of 24.2°, 33.2°, 35.7°, 40.9°, 49.5°, 54.1°, 62.5°, and 64.0°, corresponding to the (012), (104), (110), (113), (024), (116), (214), and (300) crystal planes in Fe2O3 (PDF# 87-1165). The results indicate that well-crystallized Fe2O3 phases were successfully formed in both MOF-derived materials and the Pt / Fe2O3-M catalyst. Further comparison of the XRD patterns of Fe2O3-M and pure Fe2O3 revealed an additional diffraction peak near 2θ=39.8° in both Pt / Fe2O3-M and Pt / Fe2O3-M samples. Figure 2 (b) This peak can be attributed to the (111) crystal plane of metallic Pt (PDF# 04-0802), thus confirming that Pt nanoparticles were successfully loaded onto the carrier surface.

[0053] The porous structure of the synthesized support and catalyst was characterized by N2 adsorption-desorption isotherms and pore size distribution analysis, and the results are as follows: Figure 3As shown in Table 1, compared with the material MIL-100(Fe) which has a high specific surface area, the specific surface area and pore volume of its oxidized derivative Fe2O3-M both decreased significantly. This phenomenon is mainly attributed to the collapse of the framework structure of MIL-100(Fe) during high-temperature calcination, resulting in the loss of the original pore structure. Further pore size distribution data (Table 1) show that the average pore sizes of the catalysts Pt / Fe2O3-M and Pt / Fe2O3 are 39.59 nm and 40.23 nm, respectively, indicating that both exhibit typical mesoporous structure characteristics. After loading Pt nanoparticles, the specific surface area of ​​Pt / Fe2O3-M (6.3 m² / g) did not change significantly compared to its support Fe2O3-M, which is attributed to the inherently smaller specific surface area of ​​the oxide support itself. It is worth noting that the specific surface area of ​​Pt / Fe2O3-M is significantly higher than that of Pt / Fe2O3 (3.0 m² / g), indicating that using MIL-100(Fe) with a high specific surface area and porous structure as a precursor helps to derive a metal oxide support with better porosity, thereby providing a better dispersion environment for the active components. Furthermore, the mesoporous channels facilitate the uniform distribution of Pt NPs in the Fe2O3-M support and improve the accessibility of active sites in the selective oxidation of GLY.

[0054] Table 1: Physicochemical properties of different supports and their corresponding supported catalysts

[0055]

[0056] The morphological characteristics of the catalyst as shown in the scanning electron microscope (SEM) are as follows: Figure 4 As shown, the Fe2O3-M catalyst exhibits a unique coral-like structure, rather than the original metallic framework structure of MOFs, which is consistent with the results of the N2 adsorption-desorption isotherm. This is due to the collapse of the original three-dimensional structure of MOFs during high-temperature carbonization. More importantly, no significant change was observed in the Pt / Fe2O3-M ratio after loading Pt NPs. Figure 4 (a) and Figure 4 (c)). The unique coral-like structure of Pt / Fe2O3-M facilitates the high dispersion of PtNPs, the accessibility of Pt active sites, and the diffusion of GLY molecules, thereby further promoting the catalytic activity and stability of Pt / Fe2O3-M in GLY oxidation. In contrast, the surface morphology of Fe2O3 exhibits an irregular blocky structure ( Figure 4 (b) and Figure 4 (d) is mainly formed by the accumulation of multiple particles. The surface structure of the catalyst has a significant impact on the diffusion, adsorption, and activation of GLY, and thus affects the catalytic activity of the catalyst.

[0057] The microstructure and elemental distribution of the Pt / Fe2O3-M catalyst were systematically characterized by transmission electron microscopy (TEM). TEM images ( Figure 5 (a) shows that the Pt nanoparticles are uniformly distributed on the Fe2O3-M support, and no obvious aggregation was observed. Particle size statistics indicate that ( Figure 5 (c) Most Pt NPs are concentrated in the 5-6 nm range, exhibiting a narrow size distribution. High-resolution HRTEM images further reveal their crystal structure. Figure 5 As shown in (b), clear lattice fringes with a spacing of 0.227 nm were observed, corresponding to the (111) crystal plane of metallic Pt; simultaneously, lattice fringes with a spacing of 0.270 nm were identified in the support region. Figure 5 (d) corresponds to the (104) crystal plane of Fe2O3, a result consistent with X-ray diffraction analysis, confirming the major exposed crystal planes of the support. To further evaluate the elemental spatial distribution of the catalyst, energy-dispersive X-ray spectroscopy (EDS) surface scanning analysis was performed. Figure 5 As shown in (eh), Pt, Fe, and O elements are uniformly distributed in the selected region, indicating that Pt nanoparticles are well dispersed on the support surface. Due to the low actual loading of Pt, its EDS signal intensity is relatively weak, appearing as sparse but uniform point signals in the elemental distribution map. In contrast, the Fe and O signals are densely distributed due to the support being the main component, reflecting the dominant role of Fe2O3-M as the substrate material. Figure 5 (i) TEM-mapping also showed the same conclusion. The TEM and EDS results together confirmed that Pt nanoparticles were successfully and uniformly loaded on the Fe2O3-M support, while maintaining good nanoscale and crystal structure. This provides an important structural basis for the high exposure of active sites and excellent catalytic performance of the catalyst.

[0058] The surface chemical state and electron transfer of the Pt-based catalyst were further investigated using X-ray photoelectron spectroscopy (XPS). Figure 6 Charge correction was performed using the C 1s peak at 284.8 eV, and the Gaussian-Lorentz GL mixing function peak fitting method was used for fitting. Three peaks were observed in the O 1s spectra of Pt / Fe2O3-M and Pt / Fe2O3, belonging to lattice oxygen (O... α The peak is at 529.9 eV, with oxygen vacancies (O) β At 531.7 and 531.9 eV and adsorbed oxygen (O γ ) at 532.5 and 532.7 eV ( Figure 3-7 (a) and (b)). XPS analysis showed that the O2 content of Pt / Fe2O3-M and Pt / Fe2O3 catalysts was significantly reduced. β / (O α + O γ The ratios were 1.38 and 0.92, respectively. The Pt / Fe2O3-M catalyst exhibited higher O content. β / (O α + O γ The ratio demonstrates the significant relative abundance of surface oxygen vacancies. Sufficient oxygen vacancies in the catalyst can promote the adsorption and activation of molecular oxygen on the Pt / Fe2O3-M catalyst, efficiently generating active oxygen species even under alkali-free conditions, thereby enhancing the selective oxidation of GLY.

[0059] The characteristic peaks appearing at 711.5 eV and 711.4 eV can be attributed to Fe. 3+ The species further confirm the existence of the Fe2O3 phase in Pt / Fe2O3-M and Pt / Fe2O3. Figure 6 (c) and (d)). Compared with Pt / Fe2O3, Fe in Pt / Fe2O3-M 3+ The binding energy shifts slightly towards higher binding energy directions. Figure 6 (c) and (d)), this shift reflects a significant change in the electronic structure of Fe in the Fe2O3-M support, indicating a decrease in its electron cloud density. For example... Figure 6 As shown in (e), Pt 4f in Pt / Fe2O3-M 7 / 2 The binding energy is 71.0 eV, close to the standard binding energy of metallic Pt (71.2 eV), indicating that Pt exists primarily in the metallic state. It is noteworthy that this binding energy is not only slightly lower than the binding energy of standard metallic Pt, but also significantly lower than that of Pt4f in commercial Pt / C catalysts. 7 / 2 The binding energy is 71.5 eV. This negative shift in binding energy indicates an increase in the electron cloud density on the surface of the Pt nanoparticles, suggesting electron transfer from the support to the Pt species. Notably, compared to Pt / Fe₂O₃, the Pt 4f in Pt / Fe₂O₃-M... 7 / 2 The negative shift in binding energy is more significant. Figure 6 (f) indicates that the electron transfer between Pt and the support is stronger in Pt / Fe2O3-M. XPS results consistently show a strong metal-support interaction between Pt nanoparticles and the Fe2O3-M support. This not only helps improve the dispersibility and thermal stability of Pt nanoparticles but also optimizes the electronic structure of Pt active sites through interfacial electronic modulation, thereby enhancing its activity in catalytic reactions and its selectivity for glyceric acid.

[0060] Electron paramagnetic resonance (EPR) spectroscopy studies on surface oxygen vacancies in Pt / Fe2O3-M and Pt / Fe2O3. Figure 7A signal of g1=2.003 was observed on the catalyst, which is attributed to the presence of oxygen vacancies on the catalyst surface. The enhanced peak density in Pt / Fe2O3-M compared to Pt / Fe2O3 indicates that the Pt / Fe2O3-M catalyst has a richer oxygen vacancy content.

[0061] Figure 9 The values ​​indicate the elution times of each product under HPLC, where each product is represented as follows: TA: malonic acid; GA: glyoxylic acid; GLA: glyceric acid; GLD: glyceraldehyde; GCA: glycolic acid; DHA: dihydroxyacetone.

[0062] Figure 10 The standard for each product under HPLC is represented as follows: TA: malonic acid; GA: glyoxylic acid; GLA: glyceric acid; GLD: glyceraldehyde; GCA: glycolic acid; DHA: dihydroxyacetone.

[0063] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing highly active Pt-based MOFs-derived metal oxide materials, characterized in that, Includes the following steps: Step S1: Preparation of MIL-100(Fe) precursor, the process includes: H3BTC is dissolved in NaOH solution, FeCl2 aqueous solution is slowly added dropwise to form a mixed solution, stirred at low speed and centrifuged at high speed, the obtained solid is placed in ammonium fluoride aqueous solution, reacted in a high pressure reactor at 60-80℃ for 2-4 h, cooled to room temperature, centrifuged, the obtained solid is washed with deionized water and ethanol, dried, to form MIL-100(Fe) precursor; Step S2: Preparation of Fe2O3-M support, the process includes: placing the MIL-100(Fe) precursor in a tube furnace and heating at 10°C / min. -1 The heating rate was increased to 700-900℃, and the temperature was carbonized at 700-900℃ for 1-2 h under O2 conditions to obtain Fe2O3-M support; Step S3: Reduce H2PtCl6·6H2O with NaBH4 to synthesize Pt / Fe2O3-M catalyst by impregnation method. The process includes: dissolving H2PtCl6·6H2O and the Fe2O3-M support in deionized water, stirring and mixing, slowly adding NaBH4 solution dropwise to the mixed solution, continuing stirring, centrifuging at high speed and washing, drying, and grinding the obtained solid into powder to obtain Pt / Fe2O3-M catalyst, which is a highly active Pt-based MOFs-derived metal oxide material.

2. The method for preparing highly active Pt-based MOFs-derived metal oxide materials according to claim 1, characterized in that, In step S1, the preparation process of the MIL-100 (Fe) precursor includes: dissolving 0.5603 g H3BTC in 10 mL of 1 mol / L NaOH solution, then slowly adding 40 mL of 0.1 M FeCl2 aqueous solution to form a mixed solution, stirring at 450 rpm for 24 h, then centrifuging at 5500 rpm for 3 min to separate the solid sample, placing it in 40 mL of 40 mM ammonium fluoride aqueous solution, reacting in a 50 mL high-pressure reactor at 70 ℃ for 3 h, cooling to room temperature, centrifuging to separate the solid, washing the obtained solid three times with deionized water and ethanol, and then drying at 80 ℃ to form the MIL-100 (Fe) precursor.

3. The method for preparing highly active Pt-based MOFs-derived metal oxide materials according to claim 1, characterized in that, In step S2, the preparation process of the Fe2O3-M support includes: placing the MIL-100(Fe) precursor in a tube furnace and heating at 10°C / min. -1 The heating rate was increased to 800℃, and the mixture was carbonized at 800℃ for 1 hour under O2 conditions to obtain the Fe2O3-M support.

4. The method for preparing highly active Pt-based MOFs-derived metal oxide materials according to claim 1, characterized in that, In step S3, the loading of Pt is 3.00 wt%.

5. The method for preparing highly active Pt-based MOFs-derived metal oxide materials according to claim 1, characterized in that, In step S3, 0.0398 g of H2PtCl6·6H2O and 0.5 g of Fe2O3-M support powder were dissolved in 50 mL of deionized water and stirred for 5 h. Then, 5 mL of 0.1 M NaBH4 solution was slowly added dropwise to the mixed solution and stirred for another 1 h. The resulting solution was then centrifuged at 8000 rpm and washed, and dried overnight in an oven at 60 °C. The resulting solid was then ground into powder to obtain the final product.

6. A highly active Pt-based MOFs-derived metal oxide material, characterized in that, The highly active Pt-based MOFs-derived metal oxide material was prepared by the method described in any one of claims 1 to 5.

7. The application of the highly active Pt-based MOFs-derived metal oxide material of claim 6 in the catalytic production of glycerol from glyceric acid.

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