Metal nanoparticle confined porous organic framework composites and methods of preparation

Abstract

The application discloses a kind of preparation of metal nanoparticle confined porous organic framework (POFs) composite based on laser implantation, under the condition of any catalyst, POFs precursor is directly added to laser-prepared metal nanoparticle organic colloid, in-situ polymerization reaction is carried out, and metal nanoparticles are successfully encapsulated into POFs pores uniformly.The preparation method of the application is simple and easy to operate, and has strong universality, and does not need traditional acid catalytic polymerization.The prepared nanoparticle confined POFs composite has the characteristics of metal loading, uniform distribution and "bulk phase confinement", and has good potential application prospect in the field of heterogeneous catalysis.

Description

Technical Field

[0001] The present invention relates to the technical field of new material preparation, and in particular to a method for preparing a porous organic framework material. Background Art

[0002] Porous organic frameworks (POFs) are a class of organic polymer materials composed of lightweight elements such as C, H, N, and O. They offer advantages such as large surface area, lightweight porosity, and tunable topology and chemical structure, making them promising for heterogeneous catalysis. However, despite their excellent porous confinement properties, POFs lack metal catalytic sites, severely limiting their effective use in heterogeneous catalysis.

[0003] Transition metal and rare earth metal nanoparticles, due to their unique electronic geometry and tunable d-band centers, possess excellent catalytic activity and are widely used in heterogeneous catalysis. Metal catalytic activity often exhibits a significant "size effect." Generally speaking, the smaller the metal size, the stronger the catalytic activity. However, after nanosizing, metals must be loaded onto a support to catalyze heterogeneous reactions. However, metal nanoparticles are prone to agglomeration and inactivation during the catalytic process, severely affecting their catalytic stability. Therefore, overcoming the bottleneck of metal nanosizing's easy agglomeration and inactivation is key to obtaining highly efficient catalysts.

[0004] Encapsulating highly active metal nanoparticles within polyolefin (POF)-based fluoropolymers (PFs) can effectively mitigate the aggregation and deactivation of metal catalysts. The "confinement effect" between POFs and metal nanoparticles not only enhances metal activity but also effectively inhibits metal nanoparticle aggregation and deactivation, thereby simultaneously improving both metal catalytic activity and stability. However, current synthesis methods mostly rely on a "post-adsorption-reduction" approach, where POFs are first prepared using an acetic acid-catalyzed Schiff base reaction. A metal salt solution is then post-adsorbed onto the POF support, and finally chemically reduced using sodium borohydride or other methods to obtain the metal nanoparticle-confined POF composite. However, this method involves lengthy synthesis steps and an uncontrollable reduction process. Furthermore, the reducing agents involved in the preparation process may damage the structure of the POF support. Furthermore, the resulting "surface-supported" composites often suffer from large and unevenly distributed metal size, low catalytic activity, and inefficient metal utilization. These factors severely restrict the application of metal nanoparticles and their POF-based composites in heterogeneous catalysis. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a metal nanoparticle confined porous organic framework composite material and preparation method that achieves uniform bulk distribution of metal nanoparticles in the POFs pores, fully utilizes the activity of nano-metal and the pore mass transfer confinement characteristics of POFs materials, and takes into account the high activity and high stability of metal catalysts.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a metal nanoparticle confined porous organic framework composite material, comprising the following steps:

[0007] Step 1: Prepare a colloidal mother solution containing metal nanoparticles:

[0008] The wavelength is 355~1064nm and the laser flux is 0.1~2Jpulse -1 cm -2 Nanosecond pulse laser bombards a metal target placed in 20-40 ml of solvent for 1-20 minutes to obtain a metal nanoparticle solution containing 0.1-50 mg / mL of metal nanoparticles;

[0009] Next, a pulse with a flux of 0.1 to 2 J is used. -1 cm -2 The metal nanoparticle solution is irradiated with a nanosecond pulse laser for 5-10 minutes to obtain a colloidal mother solution containing metal nanoparticles;

[0010] Wherein, the solvent is one of n-butanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide;

[0011] Step 2: Preparation of metal nanoparticle confined porous organic framework composite materials:

[0012] Ultrasonic dispersion of the porous organic framework precursor in 20-40 ml of a colloidal mother solution containing metal nanoparticles to form a porous organic framework reaction system;

[0013] The porous organic framework reaction system is placed at a temperature of 25 to 120°C and allowed to react for 2 to 96 hours. After the reaction is completed, the precipitate is washed alternately with N,N-dimethylformamide and ethanol at least three times, the precipitated powder is collected, and vacuum dried at 80°C for 10 to 14 hours to obtain a metal nanoparticle confined porous organic framework composite material.

[0014] Furthermore, the metal nanoparticles are at least one of Pt, Pd, Au, Ru, Cu, Ag, Ni, Co, V, Cr, In, Ga, Er, Sm or Gd.

[0015] Furthermore, the porous organic framework precursor includes an aldehyde precursor and an amine precursor, wherein the ratio of the total amount of aldehyde groups in the aldehyde precursor to the total amount of amino groups in the amine precursor is 1 / 1.

[0016] Furthermore, the aldehyde precursor is one of terephthalaldehyde, substituted terephthalaldehyde, isophthalic acid trimeraldehyde, biphenyl dicarboxaldehyde, substituted biphenyl dicarboxaldehyde, terphenyl dicarboxaldehyde, substituted terphenyl dicarboxaldehyde and trialdehyde phloroglucinol.

[0017] Furthermore, the amine precursor is one of p-phenylenediamine, substituted p-phenylenediamine, benzyl diamine, substituted benzyl dimethylamine, terphenyl dimethylamine, substituted terphenyl dimethylamine and 1,3,5-triaminobenzene.

[0018] Furthermore, the porous organic framework of the porous organic framework material obtained from the porous organic framework precursor is POF.

[0019] The present invention also provides a metal nanoparticle confined porous organic framework composite material prepared based on the above preparation method, which is metal nanoparticles uniformly confined in the pores of the porous organic framework material.

[0020] The beneficial effects of the present invention are:

[0021] (1) The metal nanoparticle-confined POFs composite material prepared by the present invention has a distinct "bulk confinement effect" and does not contain any impurities such as surfactants and reducing agents. The metal is highly dispersed, uniform in size, and encapsulated into the POFs pores, which has great application prospects in the field of heterogeneous catalysis.

[0022] (2) The present invention can prepare metal particle confined POFs composite materials in a green, simple, efficient and universal manner, and the in-situ encapsulation strategy involved successfully achieves high-quality confinement of metal nanoparticles in POFs pores.

[0023] (3) The metal particle confined POFs composite material prepared by the present invention has obvious "bulk encapsulation confinement" characteristics and is expected to be widely used in heterogeneous catalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a high-resolution transmission electron microscopy (HRTEM) image of the Pt nanoparticle confined POF composite material Pt@POF1 prepared in Experimental Example 1 of the present invention;

[0025] Figure 2 (a) X-ray photoelectron spectroscopy (XPS) of Pt@POF1 prepared in Experimental Example 1 of the present invention;

[0026] Figure 2 (b) is the Fourier transform infrared (ATR-FTIR) spectrum of Pt@POF1 prepared in Experimental Example 1 of the present invention and POF1 prepared in Comparative Example 1;

[0027] Figure 3Powder X-ray diffraction (PXRD) spectra of Pt@POF1 prepared in Experimental Example 1 of the present invention and POF1 prepared in Comparative Example 1. DETAILED DESCRIPTION

[0028] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] In order to achieve the above object, the present invention provides the following specific implementation methods:

[0030] Example 1:

[0031] A method for preparing a metal nanoparticle confined porous organic framework composite material comprises the following steps:

[0032] Step 1: Prepare a colloidal mother solution containing metal nanoparticles:

[0033] The wavelength is 355~1064nm and the laser flux is 0.1~2Jpulse -1 cm -2 Nanosecond pulse laser bombards a metal target placed in 20-40 ml of solvent for 1-20 minutes to obtain a metal nanoparticle solution containing 0.1-50 mg / mL of metal nanoparticles;

[0034] Among them, the metal nanoparticles are at least one of Pt, Pd, Au, Ru, Cu, Ag, Ni, Co, V, Cr, In, Ga, Er, Sm or Gd.

[0035] The solvent is one of n-butanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide;

[0036] Next, a pulse with a flux of 0.1 to 2 J is used. -1 cm -2 The metal nanoparticle solution is irradiated with a nanosecond pulse laser for 5-10 minutes to obtain a colloidal mother solution containing metal nanoparticles;

[0037] Step 2: Preparation of metal nanoparticle confined porous organic framework composite materials:

[0038] The porous organic framework precursor is ultrasonically dispersed in 20-40 ml of a colloidal mother liquor containing metal nanoparticles to form a porous organic framework reaction system; wherein the porous organic framework precursor includes an aldehyde precursor and an amine precursor, wherein the ratio of the total amount of aldehyde groups in the aldehyde precursor to the total amount of amino groups in the amine precursor is 1 / 1.

[0039] The aldehyde precursor is one of terephthalaldehyde, substituted terephthalaldehyde, isophthalic acid trimeraldehyde, biphenyl dicarboxaldehyde, substituted biphenyl dicarboxaldehyde, terphenyl dicarboxaldehyde, substituted terphenyl dicarboxaldehyde and trialdehyde phloroglucinol.

[0040] The amine precursor is one of p-phenylenediamine, substituted p-phenylenediamine, benzyldiamine, substituted benzyldimethylamine, terphenyldimethylamine, substituted terphenyldimethylamine and 1,3,5-triaminobenzene.

[0041] The porous organic framework of the porous organic framework material obtained from the porous organic framework precursor is POF.

[0042] The porous organic framework reaction system is placed at a temperature of 25 to 120°C and allowed to react for 2 to 96 hours. After the reaction is completed, the precipitate is washed alternately with N,N-dimethylformamide and ethanol at least three times, the precipitated powder is collected, and vacuum dried at 80°C for 10 to 14 hours to obtain a metal nanoparticle confined porous organic framework composite material.

[0043] To further illustrate the present invention, an experimental example is provided in which the porous organic framework material obtained from the porous organic framework precursor is abbreviated as POFX. Here, X is used to distinguish POFs synthesized from any combination of aldehyde and amine precursors, and X is equal to 1, 2, 3, etc.

[0044] In this embodiment, the metal nanoparticles are Pt, Pd, V or Ga, the amine precursor is p-phenylenediamine, the aldehyde precursor is trialdehyde phloroglucinol, and the synthesized POF is POF1.

[0045] Experimental Example 1: Preparation of Pt@POF1:

[0046] (1) The wavelength is 1064nm and the laser flux is 1.2Jpulse -1 cm -2 The Pt foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 10 min to obtain a dimethyl sulfoxide mother liquor containing Pt nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 The dimethyl sulfoxide colloidal solution containing Pt nanoparticles was obtained by secondary bombardment with a pulsed laser for 10 min.

[0047] (2) 324.42 mg of p-phenylenediamine and 420.28 mg of trialdehyde phloroglucinol were directly added to 40 mL of dimethyl sulfoxide colloidal solution containing Pt nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain a Pt nanoparticle-confined POF1 composite material.

[0048] Experimental Example 2:

[0049] Preparation of Pd@POF1:

[0050] (1) The wavelength is 1064nm and the laser flux is 1.0Jpulse -1 cm -2 The Pd foil in 20 mL of N, N-dimethylformamide was bombarded with a nanosecond pulse laser for 10 min to obtain an N, N-dimethylformamide mother liquor containing Pd nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse -1 cm -2 After secondary bombardment with a pulsed laser for 10 min, an N,N-dimethylformamide colloidal solution containing Pd nanoparticles was obtained;

[0051] (2) 324.42 mg of p-phenylenediamine and 420.28 mg of trialdehyde pyrogallol were directly added to 40 mL of N,N-dimethylformamide colloidal solution containing Pd nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain a Pd nanoparticle-confined POF1 composite material.

[0052] Experimental Example 3:

[0053] Preparation of V@POF1:

[0054] (1) The wavelength is 1064nm and the laser flux is 1.2Jpulse -1 cm -2 The V foil in 20 mL of n-butanol was bombarded with a nanosecond pulse laser for 10 min to obtain a n-butanol mother liquor containing V nanoparticles; the obtained mother liquor was treated with a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with pulsed laser for 10 min, a n-butanol colloidal solution containing V nanoparticles was obtained;

[0055] (2) 324.42 mg of p-phenylenediamine and 420.28 mg of trialdehyde phloroglucinol were ultrasonically dispersed in 40 mL of n-butanol colloidal solution containing V nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain a V nanoparticle-confined POF1 composite material.

[0056] Experimental Example 4:

[0057] Preparation of Ga@POF1:

[0058] (1) The wavelength is 1064nm and the laser flux is 1.0Jpulse-1 cm -2 The Ga foil in 20 mL of n-butanol was bombarded with a nanosecond pulse laser for 2 min to obtain a n-butanol mother liquor containing Ga nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with a pulsed laser for 10 min, a n-butanol colloidal solution containing Ga nanoparticles was obtained;

[0059] (2) 324.42 mg of p-phenylenediamine and 420.28 mg of trialdehyde phloroglucinol were ultrasonically dispersed in 40 mL of n-butanol colloidal solution containing Ga nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain a Ga nanoparticle-confined POF1 composite material.

[0060] Example 2: Same as Example 1, except that:

[0061] The metal nanoparticles are Cr or Ni, the amine precursor is p-phenylenediamine, the aldehyde precursor is m-phenylenedialdehyde, and the synthesized POF is POF2.

[0062] In order to further illustrate Example 2, the following specific experimental examples 5-6 are provided:

[0063] Experimental Example 5:

[0064] Preparation of Cr@POF2:

[0065] (1) The wavelength is 1064nm and the laser flux is 0.5Jpulse -1 cm -2 The Cr foil in 20 mL of n-butanol was bombarded with a nanosecond pulse laser for 2 min to obtain a n-butanol mother liquor containing Cr nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with a pulsed laser for 10 min, a n-butanol colloidal solution containing Cr nanoparticles was obtained;

[0066] (2) 324.42 mg of p-phenylenediamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of n-butanol colloidal solution containing Cr nanoparticles and allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times. The resulting powder was vacuum dried at 80 °C for 12 h to obtain a Cr nanoparticle-confined POF2 composite material.

[0067] Experimental Example 6:

[0068] Preparation of Ni@POF2:

[0069] (1) The wavelength is 1064nm and the laser flux is 0.5Jpulse -1 cm -2 The Ni foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Ni nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with a pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Ni nanoparticles was obtained;

[0070] (2) 324.42 mg of p-phenylenediamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Ni nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain a Ni nanoparticle-confined POF2 composite material.

[0071] Example 3: Same as Example 1, except that:

[0072] The metal nanoparticles are Au or Ru, the amine precursor is dichloro-p-phenylenediamine, the aldehyde precursor is m-phenylenedialdehyde, and the synthesized POF is POF3. To further illustrate Example 3, the following specific experimental examples 7-8 are provided:

[0073] Experimental Example 7:

[0074] Preparation of Au@POF3:

[0075] (1) The wavelength is 1064nm and the laser flux is 1.0Jpulse -1 cm -2 The Au foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Au nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Au nanoparticles was obtained;

[0076] (2) 531.09 mg of dichloro-p-phenylenediamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Au nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain an Au nanoparticle-confined POF3 composite material.

[0077] Experimental Example 8:

[0078] Preparation of Ru@POF3:

[0079] (1) The wavelength is 1064nm and the laser flux is 1.6Jpulse -1 cm -2 The Ru foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Ru nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with a pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Ru nanoparticles was obtained;

[0080] (2) 531.09 mg of dichloro-p-phenylenediamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Ru nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was then washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain a Ru nanoparticle-confined POF3 composite material.

[0081] Example 4: Same as Example 1, except that:

[0082] The metal nanoparticles are Ag, Er, Gd or Sm, the amine precursor is benzyl diamine, the aldehyde precursor is m-phenylenedialdehyde, and the synthesized POF is POF4.

[0083] In order to further illustrate Example 4, the following specific experimental examples 9-12 are provided:

[0084] Experimental Example 9:

[0085] Preparation of Ag@POF4:

[0086] (1) The wavelength is 1064nm and the laser flux is 0.5Jpulse -1 cm -2 The Ag foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Ag nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Ag nanoparticles was obtained;

[0087] (2) 324.72 mg of benzyl diamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Ag nanoparticles, and the mixture was allowed to react at 40 °C for 2 h. The resulting precipitate was then washed alternately with N,N-dimethylformamide and ethanol three times, and the resulting powder was vacuum dried at 80 °C for 12 h to obtain an Ag nanoparticle-confined POF4 composite material.

[0088] Experimental Example 10:

[0089] Preparation of Er@POF4:

[0090] (1) The wavelength is 1064nm and the laser flux is 0.5Jpulse -1 cm -2 The Er foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Er nanoparticles; the obtained mother liquor was treated with a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Er nanoparticles was obtained;

[0091] (2) 324.72 mg of benzyl diamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Er nanoparticles and allowed to react at 40 °C for 2 h. The resulting precipitate was then washed alternately with N,N-dimethylformamide and ethanol three times. The resulting powder was vacuum dried at 80 °C for 12 h to obtain an Er nanoparticle-confined POF4 composite material.

[0092] Experimental Example 11:

[0093] Preparation of Gd@POF4:

[0094] (1) The wavelength is 1064nm and the laser flux is 0.5Jpulse -1 cm -2 The Gd foil in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Gd nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Gd nanoparticles was obtained;

[0095] (2) 324.72 mg of benzyl diamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Gd nanoparticles and allowed to react at 40 °C for 2 h. The resulting precipitate was then washed alternately with N,N-dimethylformamide and ethanol three times. The resulting powder was vacuum dried at 80 °C for 12 h to obtain a Gd nanoparticle-confined POF4 composite material.

[0096] Experimental Example 12:

[0097] Preparation of Sm@POF4:

[0098] (1) The wavelength is 1064nm and the laser flux is 0.5Jpulse -1 cm -2 The Sm foil placed in 20 mL of dimethyl sulfoxide was bombarded with a nanosecond pulse laser for 2 min to obtain a dimethyl sulfoxide mother liquor containing Sm nanoparticles; the obtained mother liquor was subjected to a 1.4 J pulse laser. -1 cm -2 After secondary bombardment with pulsed laser for 10 min, a dimethyl sulfoxide colloidal solution containing Sm nanoparticles was obtained;

[0099] (2) 324.72 mg of benzyl diamine and 324.28 mg of isophthalic acid were ultrasonically dispersed in 40 mL of dimethyl sulfoxide colloidal solution containing Sm nanoparticles and allowed to react at 40 °C for 2 h. The resulting precipitate was then washed alternately with N,N-dimethylformamide and ethanol three times. The resulting powder was vacuum dried at 80 °C for 12 h to obtain a Sm nanoparticle-confined POF4 composite material.

[0100] In order to demonstrate the technical effects of the present invention, the present invention also provides the following comparative examples for comparison and explanation with the present invention:

[0101] Comparative Example 1: Preparation of pure POF1,

[0102] 324.42 mg of p-phenylenediamine and 420.28 mg of trialdehyde phloroglucinol were added to 40 mL of dimethyl sulfoxide, followed by 10 mL of 6 M glacial acetic acid. The mixture was allowed to react at 40 °C for 12 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and dried in vacuo at 80 °C for 12 h to obtain POF1 material.

[0103] Comparative Example 2: Preparation of pure POF2,

[0104] 324.42 mg of p-phenylenediamine and 324.28 mg of isophthalic acid were added to 40 mL of dimethyl sulfoxide, followed by the addition of 10 mL of 6 M glacial acetic acid. The mixture was allowed to react at 40 °C for 12 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and dried in vacuo at 80 °C for 12 h to obtain POF2 material.

[0105] Comparative Example 3: Preparation of pure POF3,

[0106] 531.09 mg of dichloro-p-phenylenediamine and 324.28 mg of isophthalic acid were added to 40 mL of dimethyl sulfoxide, followed by 10 mL of 6 M glacial acetic acid. The reaction was allowed to stand at 40 °C for 12 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and dried in vacuo at 80 °C for 12 h to obtain POF3 material.

[0107] Comparative Example 4: Preparation of pure POF4,

[0108] 324.72 mg of benzyl diamine and 324.28 mg of isophthalic acid were added to 40 mL of dimethyl sulfoxide, followed by 10 mL of 6 M glacial acetic acid. The mixture was allowed to react at 40 °C for 12 h. The resulting precipitate was washed alternately with N,N-dimethylformamide and ethanol three times, and dried in vacuo at 80 °C for 12 h to obtain POF4 material.

[0109] Example 5: Figure 1-3 As shown, the present invention also provides a metal nanoparticle confined porous organic framework composite material prepared based on the above preparation method, which is metal nanoparticles uniformly confined in the pores of the porous organic framework material.

[0110] Figure 1 This is a high-resolution transmission electron microscopy (HRTEM) image of the Pt nanoparticle confined POF1 composite material (Pt@POF1) prepared in Experimental Example 1. Figure 1 It can be seen that the Pt@POF1 composite material synthesized in the present invention does not contain uneven large Pt particles, and the Pt species are evenly distributed, with sizes almost all being about 2 nm.

[0111] Figure 2 (a) is the X-ray photoelectron spectrum (XPS) of Pt@POF1 prepared in Experimental Example 1. Figure 2 (b) is the Fourier transform infrared spectrum (ATR-FTIR) of Pt@POF1 prepared in Example 1 and POF1 prepared in Comparative Example 1. Figure 2 (a) It can be seen that the Pt valence state in the Pt@POF1 composite material prepared by the present invention is +2; Figure 2 (b) It can be seen that the 1624 cm-1 of the Pt@POF1 composite material prepared by the present invention-1 There is obvious vibration absorption of the imine bond at the position of the amine precursor, which proves that the aldehyde and amine precursors are polymerized into imine POF1 without any catalyst.

[0112] Figure 3 The X-ray powder diffraction (XRD) spectra of Pt@POF1 prepared in Experimental Example 1 and Comparative Example 1 and POF1 prepared in Comparative Example 1 show that the preparation method of the in-situ implantation of metal nanoparticles into POF material provided by the present invention has no effect on the crystallinity of POF, and the obtained nanoparticle confined POF composite material has excellent crystallinity and ordered structure.

[0113] In summary, the metal nanoparticle-confined POFs prepared by the present invention exhibit high purity, are free of impurity ions, exhibit excellent crystallinity, and exhibit highly uniform distribution of the nanoparticles within the POF pores, potentially offering advantages in heterogeneous catalysis, balancing catalytic activity and stability. Furthermore, the preparation method provided by the present invention is simple, versatile, and readily applicable, offering promising potential applications in heterogeneous catalysis.

[0114] The above description is only a preferred experimental example of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a metal nanoparticle confined porous organic framework composite material, characterized in that: The following steps are involved: Step 1: Prepare a colloidal mother solution containing metal nanoparticles: The wavelength is 355~1064nm and the laser flux is 0.1~2Jpulse -1 cm -2 Nanosecond pulse laser bombards a metal target placed in 20-40 ml of solvent for 1-20 minutes to obtain a metal nanoparticle solution containing 0.1-50 mg / mL of metal nanoparticles; Next, a pulse with a flux of 0.1 to 2 J is used. -1 cm -2 The metal nanoparticle solution is irradiated with a nanosecond pulse laser for 5-10 minutes to obtain a colloidal mother solution containing metal nanoparticles; Wherein, the solvent is one of n-butanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide; Step 2: Preparation of metal nanoparticle confined porous organic framework composite materials: Ultrasonic dispersion of the porous organic framework precursor in 20-40 ml of a colloidal mother solution containing metal nanoparticles to form a porous organic framework reaction system; The porous organic framework reaction system is placed at a temperature of 25 to 120°C and allowed to react for 2 to 96 hours. After the reaction is completed, the precipitate is washed alternately with N,N-dimethylformamide and ethanol at least three times, the precipitated powder is collected, and vacuum dried at 80°C for 10 to 14 hours to obtain a metal nanoparticle confined porous organic framework composite material.

2. The method for preparing the metal nanoparticle confined porous organic framework composite material according to claim 1, characterized in that: The metal nanoparticles are at least one of Pt, Pd, Au, Ru, Cu, Ag, Ni, Co, V, Cr, In, Ga, Er, Sm or Gd.

3. The method for preparing the metal nanoparticle confined porous organic framework composite material according to claim 1, wherein: The porous organic framework precursor comprises an aldehyde precursor and an amine precursor, wherein the ratio of the total amount of aldehyde groups in the aldehyde precursor to the total amount of amino groups in the amine precursor is 1 / 1.

4. The method for preparing the metal nanoparticle confined porous organic framework composite material according to claim 3, wherein: The aldehyde precursor is one of terephthalaldehyde, substituted terephthalaldehyde, isophthalic acid trimeraldehyde, biphenyl dicarboxaldehyde, substituted biphenyl dicarboxaldehyde, terphenyl dicarboxaldehyde, substituted terphenyl dicarboxaldehyde and trialdehyde phloroglucinol.

5. The method for preparing the metal nanoparticle confined porous organic framework composite material according to claim 3, wherein: The amine precursor is one of p-phenylenediamine, substituted p-phenylenediamine, benzyldiamine, substituted benzyldimethylamine, terphenyldimethylamine, substituted terphenyldimethylamine and 1,3,5-triaminobenzene.

6. The method for preparing the metal nanoparticle confined porous organic framework composite material according to any one of claims 1 to 5, characterized in that: The porous organic framework of the porous organic framework material obtained from the porous organic framework precursor is POF.

7. A metal nanoparticle confined porous organic framework composite material prepared by the preparation method according to claims 1-5, characterized in that: Metal nanoparticles uniformly confined in the pores of porous organic framework materials.

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