Indium-based sulfur high-value catalyst, preparation method and application thereof

Abstract

The application discloses an indium-based sulfur high-value catalyst, a preparation method and application thereof, and belongs to the technical field of material preparation and environmental catalysis. Nitrogen-carbon polymers with a nanosieve morphology are used as carriers, and In is bonded to the carriers in the form of a single-atom In-N X chemical bond. The application has simple and easy-to-implement synthesis steps, good repeatability, and can realize the regulation and optimization of the electronic structure and surface properties of the catalyst by using the In-N X chemical coordination to bond In atoms on the nitrogen-carbon carrier. The catalyst has a high specific surface area and pore volume, and presents high catalytic activity and product selectivity in the H2S nucleophilic addition of aromatic nitrile compounds to form thio-benzamide products. The application can realize efficient removal of H2S sources and high-value utilization of H2S, has better performance than traditional catalysts such as h-BN, CuO and Fe2O3, is not prone to sulfur poisoning and carbon corrosion, can be recycled, has wide applicability to organic substrates, and has great industrial application prospects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of material preparation and environmental catalysis, and particularly relates to a preparation method of an indium-based catalyst and application of the indium-based catalyst in H2S nucleophilic addition of aryl nitrile compounds to form thio-benzamide. BACKGROUND

[0002] Hydrogen sulfide (H2S) is a highly toxic pollutant that not only destroys the ecological environment but also endangers human health. Therefore, in the past few decades, how to effectively treat H2S associated with coal chemical industry and natural gas has been an extremely important and challenging topic. The most commonly used technology for treating H2S at present is the Claus process, but this process can only recover elemental sulfur from waste gas The H element in H2S is converted into H2O and discharged as wastewater, which not only pollutes the environment but also loses a large amount of valuable hydrogen resources. Therefore, it is urgent to develop new ways and new materials that can not only effectively remove H2S but also simultaneously realize high-value utilization of the S element and the H element in H2S.

[0003] Using H2S as a "hydrogen donor", atomically economically utilizing the H element and the S element in H2S, and developing atomically economic utilization of H2S nucleophilic addition of aryl nitrile compounds to prepare high-value aryl thioamides is an effective way to realize source removal of H2S and high-value utilization of H2S. Thioamides and their derivatives are key intermediates for industrial applications and have great application prospects in the fields of biological medicines, fine chemicals, and polymer materials. Therefore, the key to this reaction is to design and develop new and efficient catalysts that promote the reaction.

[0004] At present, the catalysts that can effectively catalyze the conversion of H2S and the amination or amidation of nitrogen-containing aromatic organic compounds are mainly precious metal systems (Pt, Pd, Ru, Au) and transition metal (Fe, Co, Cu, Ni) systems. However, the above materials still have deficiencies, which limit their further development. For example, the precious metal system has the disadvantages of high price, limited reserves, and easy sulfur corrosion. In addition, the conventional transition metal materials have strong oxidizing properties and are easy to promote the formation of sulfates in the reaction system, leading to catalyst poisoning and deactivation. Therefore, finding a non-precious metal and transition metal catalyst with a simple and effective synthesis path is an important part of the H2S nucleophilic addition of aryl nitrile compounds to prepare thio-benzamide reaction.

[0005] We noticed that indium (In), a group IIIA element in the fifth period of the periodic table, is a green and environmentally friendly p-block metal element with an electronic configuration of [Kr]4d 10 5s 2 5p 1, has a certain polar covalent bond attribute, which is conducive to promoting the adsorption of polar molecules. At the same time, the In element with delocalized p orbital electron state can effectively regulate the electronic structure of the In active center by coordinating with nitrogen (N) element, so that it can not only participate in the activation process of the reactant molecules (CO2, H2S and other polar molecules), promote the formation of intermediates, but also reduce the desorption energy barrier of the product on the catalyst, accelerate the process of the reaction. Based on this, a kind of green, mild and scalable method for preparing In doped carbon nitrogen catalyst is creatively designed and developed, and it is applied to the H2S nucleophilic addition of aryl nitrile compound to prepare thio benzamide reaction. We first take one or more than two of melamine, cyanuric acid, thiocyanic acid, urea, dicyandiamide, thiourea, cyanamide as a polymer nitrogen carbon precursor, one or more than two of bromophenol, tetrabromobisphenol A, tribromophenol as a carbon source, one or more than two of indium chloride, indium nitrate, indium phosphide, indium bromide, isopropyl alcohol indium as a metal active In atom precursor, one or more than two of 1,10-phenanthroline, phthalocyanine, Schiff base as a space isolation agent of metal site In, realize the high dispersion of In atom anchoring on the nitrogen carbon polymer carrier. The present application provides a reference for the simple, green and scalable preparation of In-based catalyst, which has great research prospect and far-reaching academic significance. At the same time, the synthesized In-based catalyst can realize the efficient source removal of H2S and realize the high value application of H2S, and further expand the application field of In-based materials. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides an indium-based sulfur high-value catalyst, a preparation method and application thereof. The catalyst solves the problems of H2S poisoning and carbon poisoning in the desulfurization reaction process in the prior art, and can realize the catalytic conversion of H2S to aryl nitrile compounds under mild conditions to obtain high-value aryl thioamide compounds and their derivatives.

[0007] To achieve the above object, the present application adopts the following technical scheme:

[0008] An indium-based sulfur high-value catalyst is composed of a nanoscale sieve-shaped carbon nitrogen polymer as a carrier and an active p region metal In dispersed on the carrier in an atomic level; the preparation method comprises the following steps:

[0009] (1) taking the nitrogen-containing precursor for synthesizing the carbon nitride polymer, grinding into powder, and then polymerizing at a certain temperature under a certain rate of temperature rise;

[0010] (2) taking the synthesized carbon nitride polymer and dissolving in a corresponding solvent, and ultrasonic dispersing until completely dispersed;

[0011] (3) taking the carbon source and dissolving in a corresponding solvent, and ultrasonic dissolving until completely dissolved;

[0012] (4) Mix the two solutions of steps (2) and (3), and stir at room temperature for a period of time;

[0013] (5) Take the metal indium source and the corresponding ligand compound, and dissolve them in the corresponding solvent, and stir and mix at room temperature;

[0014] (6) Mix the two solutions of steps (4) and (5), stir for a period of time, centrifuge, and then dry and grind;

[0015] (7) Transfer the powder obtained in step (6) to a tube furnace, and obtain an indium-doped carbon-nitrogen polymer catalyst with a nanosieve morphology after calcination under the corresponding calcination gas.

[0016] Further, the nitrogen-containing precursor in step (1) is one or more of trichloroformamidine, formamidine, thiocyanic acid, urea, dicyanamide, thiourea, and monocyamide as a polymer nitrogen-carbon precursor.

[0017] Further, the carbon source is one or more of p-bromophenol, tetrabromobisphenol A, and tribromophenol as a carbon source, and the molar ratio of the carbon source to the polymer nitrogen-carbon precursor is 1:1-3.

[0018] Further, the indium source is one or more of indium chloride, indium nitrate, indium phosphide, indium bromide, and isopropyl alcohol indium as a metal active In atom precursor, and the ligand is one or more of 1,10-phenanthroline, phthalocyanine, and Schiff base, and the molar ratio of the indium source to the ligand is 1:1-2.

[0019] Further, the solvent is one or more of deionized water, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, triethanolamine, isopropylamine, ethanol, methanol, ethylene glycol, and diethylamine, and the amount of solvent added is 40-120 mL.

[0020] Further, the polymerization temperature in step (1) is 400-600°C, and the heating rate is 1-5°C / min.

[0021] Further, in step (6), the drying is performed at 80-120°C for 8-24h.

[0022] Further, in step (7), the calcination temperature is 600-1000°C, and the time is 2-8h.

[0023] Further, in step (7), the heating rate of calcination is 1-10°C / min.

[0024] Further, in step (7), the calcination atmosphere is one of nitrogen, ammonia, argon, and helium.

[0025] Further, the doping amount of In in the catalyst is 1-4 wt.%, and the single-atom activity is In-N X , wherein 2

[0026] Further, the specific surface area of the catalyst is 400-800 m 2 / g.

[0027] Further, the application conditions of the H2S nucleophilic addition aryl nitrile group to thioaroyl amide reaction are as follows: the reaction temperature is 30-110 DEG C, the reaction pressure is normal pressure to 2.0 MPa, the heating rate is 2.5 DEG C / min, the raw gas gas flow rate is 10-30 mL / min, the H2S concentration in the raw gas is 500-50000 ppm, and the aryl nitrile substrate content in the system is 0.1-10 mmol.

[0028] The beneficial effects of the present application are as follows:

[0029] (1) The single-atom indium-doped carbon-nitrogen polymer catalyst with nanosieve morphology provided by the present application has high specific surface area and pore volume, which is beneficial to accelerate the mass transfer diffusion process and increase the exposure of reaction active sites, and the synthesis method has the advantages of simple conditions, simple and easy steps, easy industrial production, and great application prospect.

[0030] (2) The single-atom indium-doped carbon-nitrogen polymer catalyst with nanosieve morphology provided by the present application, in which In and N are bonded through a chemical bond, can effectively improve the geometric structure and electronic structure of the In center and the surface chemical properties of the nitrogen-carbon carrier, and has good catalytic activity and product selectivity in the H2S nucleophilic addition aryl nitrile group to thioamide reaction.

[0031] (3) The single-atom indium-doped carbon-nitrogen polymer catalyst with nanosieve morphology obtained by the present application is not easy to be poisoned by sulfur, and the performance does not change obviously before and after the reaction, can be recycled, can reduce consumables, and has better performance than traditional desulfurizers such as g-C3N4, h-BN, nitrogen-doped carbon, MgO, CuO, TiO2, CeO2, ZrO2, CoO, NiO, SnO2, MnO2, MoS2, ZnO, Fe2O3 and Si / Al molecular sieve. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 X-ray powder diffraction spectra of pristine NC and In-NC prepared in Examples 1-4 of the present application;

[0033] Figure 2 N2 physical adsorption-desorption curves of pristine NC and In-NC prepared in Examples 1-4 of the present application;

[0034] Figure 3 SEM images of pristine NC and In-NC prepared for Examples 1-4 of the present application;

[0035] Figure 4 TEM, TEM Mapping images of pristine NC and In-NC prepared for Examples 1-4 of the present application;

[0036] Figure 5 XPS images of pristine NC and In-NC prepared for Examples 1-4 of the present application, a is In 3d spectrum, b is N 1s spectrum;

[0037] Figure 6 Sulfenamide yield of pristine NC and In-NC prepared for Examples 1-4 of the present application at 2h in the reaction of catalytic H2S conversion of benzonitrile;

[0038] Figure 7 Activity chart of In-NC prepared for Examples 1-4 of the present application in five rounds of testing. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present application clearer and more apparent, the present application will be described in detail below with reference to the examples and drawings, and the examples described are further illustrations of the present application, rather than limitations on the content of the present application.

[0040] Example 1

[0041] First, 10g of melamine and urea (mass ratio 1:1) were weighed and heated to 550℃ at a heating rate of 5℃ / min under a nitrogen atmosphere and held at this temperature for 4h, and after cooling to room temperature, ground into a powder to obtain a polymer carbon nitride material. Then 2.0g of the polymer carbon nitride and 2g of p-bromophenol were added to 50mL of ethanol + 50mL of deionized water, and ultrasonicated for 30min to completely disperse and dissolve. Subsequently, 100mg of indium chloride and 135mg of 1,10-phenanthroline (molar ratio 1:1) were added to the above solution, and ultrasonicated for another 30min to completely dissolve, and then stirred on a magnetic stirrer at 80℃ until evaporated to dryness, and then transferred to an oven at 80℃ for drying for 12h. The dried sample was ground and transferred into a tube furnace, and heated to 800℃ at a heating rate of 5℃ / min under a nitrogen atmosphere and held at this temperature for 4h. After natural cooling to room temperature, the resulting sample, nanosieve-shaped monatomic indium-doped carbon-nitrogen polymer catalyst, was named In-NC. 100 -NC.

[0042] Example 2

[0043] Firstly, 10 g of melamine and urea (mass ratio 1 : 1) were weighed and heated to 550 °C at a heating rate of 5 °C / min under nitrogen atmosphere and kept at this temperature for 4 h. After cooling to room temperature, the sample was ground into powder to obtain a polymer carbon nitride material. Then 2.0 g of the polymer carbon nitride and 2 g of p-bromophenol were added into 50 mL of ethanol + 50 mL of deionized water, and ultrasonic treatment was performed for 30 min to make them completely dispersed and dissolved. Subsequently, 200 mg of indium chloride and 270 mg of 1,10-phenanthroline (molar ratio 1 : 1) were added into the above solution, and ultrasonic treatment was continued for 30 min to make them completely dissolved. Then the solution was stirred at 80 °C on a magnetic stirrer until it was evaporated to dryness, and then it was transferred into an oven at 80 °C for drying for 12 h. After drying, the sample was ground and transferred into a tube furnace, and heated to 800 °C at a heating rate of 5 °C / min under nitrogen atmosphere and kept at this temperature for 4 h. After natural cooling to room temperature, the synthesized sample, a single-atom indium-doped carbon-nitrogen polymer catalyst with nanosieve morphology, was named In-NC. 200 -NC.

[0044] Example 3

[0045] Firstly, 10 g of melamine and urea (mass ratio 1 : 1) were weighed and heated to 550 °C at a heating rate of 5 °C / min under nitrogen atmosphere and kept at this temperature for 4 h. After cooling to room temperature, the sample was ground into powder to obtain a polymer carbon nitride material. Then 2.0 g of the polymer carbon nitride and 2 g of p-bromophenol were added into 50 mL of ethanol + 50 mL of deionized water, and ultrasonic treatment was performed for 30 min to make them completely dispersed and dissolved. Subsequently, 200 mg of indium chloride and 270 mg of 1,10-phenanthroline (molar ratio 1 : 1) were added into the above solution, and ultrasonic treatment was continued for 30 min to make them completely dissolved. Then the solution was stirred at 80 °C on a magnetic stirrer until it was evaporated to dryness, and then it was transferred into an oven at 80 °C for drying for 12 h. After drying, the sample was ground and transferred into a tube furnace, and heated to 800 °C at a heating rate of 5 °C / min under nitrogen atmosphere and kept at this temperature for 4 h. After natural cooling to room temperature, the synthesized sample, a single-atom indium-doped carbon-nitrogen polymer catalyst with nanosieve morphology, was named In-NC. 400 -NC.

[0046] Example 4

[0047] Firstly, 10 g of melamine and urea (mass ratio 1:1) were weighed and heated to 550 °C at a rate of 5 °C / min under nitrogen atmosphere and kept at this temperature for 4 h. After cooling to room temperature, the sample was ground into powder to obtain the polymer carbon nitride material. Then 2.0 g of the polymer carbon nitride and 2 g of p-bromophenol were added to 50 mL of ethanol + 50 mL of deionized water, and ultrasonic treatment was performed for 30 min to completely disperse and dissolve the sample. Then the sample was transferred to an oven at 80 °C and dried for 12 h. After drying, the sample was ground and transferred to a tube furnace, and heated to 800 °C at a rate of 5 °C / min under nitrogen atmosphere and kept at this temperature for 4 h. After natural cooling to room temperature, the resulting sample, a carbon-nitrogen polymer catalyst with nanosheet morphology, was named Pristine NC.

[0048] Characterization analysis:

[0049] 1. Instrumentation

[0050] X-ray powder diffraction (XRD): The XRD pattern of the catalyst was measured by a Bruker D8 Advance X-ray diffractometer with a copper target (Cu Ka, λ = 0.154 nm) X-ray tube, a Ni filter, a working voltage of 45 kV, and a current of 40 mA, and a scanning range of 2θ = 10-60°.

[0051] Specific surface area and pore size distribution determination (low-temperature N2 physical adsorption): The specific surface area and pore size distribution of the catalyst were analyzed and determined by an ASAP2020 other adsorption pore size analyzer (American Micrometrics Company). The sample chamber was vacuumed to a degree of vacuum P / P0 in the range of 0-1, and the adsorption-desorption isotherm was determined by a liquid nitrogen static adsorption method. Before testing, the catalyst was degassed at a temperature of 453 K under vacuum for 4 h, and then the adsorption-desorption isotherm was determined according to the static method, the specific surface area was calculated by the multi-point Barrett-Emmett-Teller (BET) method, and the pore volume and pore size distribution were calculated by the Barrett-Joyner-Halanda (BJH) model.

[0052] Field emission scanning electron microscopy (SEM): The SEM image of the sample was observed on an S-4800 scanning electron microscope, and the test current and voltage were 7 μA and 5 kV, respectively.

[0053] The morphology and particle size distribution of the sample were observed by a transmission electron microscope of the Netherlands Philips Company. Before testing, the sample was ultrasonically dispersed in an ethanol solution, and after 20 min, the sample was dropped on a copper grid loaded with a carbon film, and then analyzed after natural drying.

[0054] The distribution state of metal atoms in the sample was observed using a Titan Cubed Themis G2300 type convergent spherical aberration-corrected transmission electron microscope. Before testing, the sample was first dispersed in an ethanol solution and ultrasonicated, then dropped onto the fresh surface of a mica sheet, and naturally dried before analysis in the instrument.

[0055] The elemental chemical state of the sample surface was tested using an X-ray photoelectron spectrometer (ESCA CAB 250xi). A monochromatic Al Kα excitation source (1486.6 eV, 15 kV, 10.8 mA) was used. The sample was fixed on an ultra-high vacuum insulating tape after being pressed into a sheet, and the tape was pasted on the sample holder. After gradually pumping to the specified vacuum degree in the sample chamber and the sample preparation chamber, the analysis chamber was tested. The analysis chamber vacuum degree was < 10 -8 bar. The charge calibration was performed with C1s = 284.8 eV as the internal standard.

[0056] Figure 1 X-ray powder diffraction spectra of pristine NC and In-NC prepared in Examples 1-4 of the present application. As Figure 1 can be seen, all catalysts have a clear characteristic diffraction peak at 27.4° belonging to the (002) plane of nitrogen-doped carbon. The NC and In X -NC have similar XRD results, indicating that the In X -NC catalyst structure is basically the same as that of NC. No In metal signal of In oxide was detected in the XRD result graph, only the characteristic peak of NC was detected, which indicates that the metal dispersion is good, In coordinates with NC, and In atoms are successfully doped into the NC lattice. In addition, when the amount of metal added is increased from 100 mg to 400 mg, the diffraction angle shifts to a low angle, and the peak widens and becomes lower in intensity. This may be because when the amount of metal In added is too much, it will affect the thermal polymerization of NC, and In enters the NC skeleton, causing an increase in disordered C-N structure.

[0057] Figure 2 N2 physical adsorption-desorption curves of pristine NC and In-NC prepared in Examples 1-4 of the present application. As can be seen from the figure, all catalysts belong to type IV isotherm adsorption curve and appear H-3 type hysteresis loop. The pore size distribution graph shows that the catalyst has a mesoporous structure, and the pore size distribution is between 3.5-4.3 nm, which belongs to the range of mesoporous. The specific surface area of NC and In X -NC (x = 100, 200, 300) was calculated by the BET method to be 384, 710, 536 and 296 m 2 / g, respectively. Among them, the BET specific surface area and total pore volume of In 100 -NC are the largest. And the total pore volume of In 100 -NC (2.7 cm3 / g) is approximately NC (1.4cm) 3 This is twice the amount of CN (g). This is because CN is released during the material calcination process. X and CH X The fragments act as soft templates for pore formation during pyrolysis, thereby increasing the BET surface area of ​​the catalyst. A high specific surface area facilitates contact between reactants and the catalyst, and further promotes the adsorption and activation of H₂S and benzonitrile substrates.

[0058] Figure 3 These are SEM images of pristine NC and In-NC prepared in Examples 1-4 of this invention. Figure 3 It can be seen that In X -NC exhibits a loose structure composed of stacked lamellae, with many fine pores formed on the lamellae.

[0059] Figure 4 The images show TEM and TEM mapping images of pristine NC and In-NC prepared in Examples 1-4 of this invention. It can be seen that In-NC exhibits a thin, lamellar morphology. The thin lamellar structure increases the exposure of active sites due to the large contact area, which can significantly improve catalytic activity. The EDS mapping images of the samples show that indium, carbon, and nitrogen are uniformly distributed, and indium is clearly highly dispersed.

[0060] Figure 5 XPS plots of pristine NC and In-NC prepared in Examples 1-4 of this invention are shown. a is the In 3d spectrum, and b is the N1s spectrum. The results show two In 3d orbitals with good resolution in the 3d orbital plot. 5 / 2 and 3D 3 / 2 Spectral lines. In 200 -NC's In 3d 5 / 2 and 3D 3 / 2 The fitting peaks are located at 444.8 and 452.4 eV, respectively. Catalyst In 200 -NC's In 3d 5 / 2 and 3D 3 / 2 The binding energies of the In bonds all shifted to higher values, a transition likely caused by strong electronic interactions between the In and N bonds. XPS results also showed no metallic In peak at 443.8 eV, but rather a peak closer to the In peak. 3+ (443.8 eV), indicating that In 200 -In in NC, the price state of In is closer to that of In. 3+ The presence of In can be further confirmed by fitting the In-N (399.3 eV) spectrum. Figure 5b are high-resolution N 1s spectra of NC and In-NC. N 1s can be fitted into four peaks at 398.0 eV, 400.7 eV, 401.8 eV and 403.8 eV, corresponding to pyridinic N, pyrrolic N, graphitic N and oxidized N, respectively. Comparing NC and In-NC, in addition to these N species, In X -NC, in addition to these N species, In 200 -NC, an additional peak at 399.3 eV appears, which is related to In-N coordinated porphyrin-like groups. Since In-N structures start to form at 600 °C and increase dramatically at pyrolysis temperature up to 900 °C. On the other hand, under high temperature conditions, In atoms tend to be more stable by coordinating with N species. Therefore, this comparison result illustrates the combination between In and NC support.

[0061] H2S nucleophilic addition to nitrile group to thio-benzamide reaction test: pristine NC and In-NC prepared in Examples 1-4 were ground and applied to the activity test. The test conditions are as follows: catalyst dosage is 40 mg, raw gas is composed of 5% H2S and balance nitrogen, nitrile substrate concentration is 1 mmol, raw gas flow rate is 20 mL·min -1 -1, reaction time is 2 h, and reaction temperature is 60 °C. The catalysts prepared in each example were applied to the H2S nucleophilic addition to nitrile group to thio-benzamide reaction, and gas-liquid chromatography was used for quantitative analysis.

[0062] Figure 6 The thio-benzamide yield of pristine NC and In-NC prepared in Examples 1-4 in the reaction of catalyzing H2S to convert benzonitrile for 2 h. It can be observed that the conversion rate of benzonitrile and the selectivity of thio-benzamide of the catalyst NC without In are lower than those of In-NC, wherein, In 200 -NC has the best catalytic activity, and under the test conditions, the conversion rate of benzonitrile is 98%, and the selectivity of thio-benzamide product reaches 95%. With the further increase of the amount of In added, the conversion rate of benzonitrile and the selectivity of thio-benzamide are both reduced. The activity of each catalyst is ranked as follows: In 200 -NC > In 100 -NC > In 400 -NC > NC. This experimental result shows that the metal In active site formed after the appropriate amount of metal In is added to the NC framework can effectively improve the activity of the catalyst. In this way, the cycle stability test of catalyzing H2S to prepare thio-benzamide was carried out for 5 times. From Figure 7It can be seen that when the reaction times increase, the performance of the catalyst after washing can be almost recovered, and the activity has a certain decrease in the fifth test. Overall, the activity of the catalyst does not decrease significantly in the process, and the catalyst maintains high stability in performance and structure. These results confirm that the unique morphology and rich In-N X The active sites and the optimal reaction conditions make it have high long-term stability. And it is superior to h-BN, BCN, CoO, Co3O4, Fe2O3, CuO, Si / Al molecular sieve and other materials (Table 1). More importantly, the In-based catalyst can be applied to different aryl nitrile substrates and has good catalytic activity, and the substrate applicability is wide (Table 2).

[0063] Table 1 Statistical table of H2S nucleophilic addition aryl nitrile group activity of In-doped carbon nitride polymers prepared in examples 1-3 of the present application and g-C3N4, h-BN, nitrogen-doped carbon, MgO, CuO, TiO2, CeO2, ZrO2, CoO, NiO, SnO2, MnO2, MoS2, ZnO, Fe2O3 and Si / Al molecular sieve

[0064]

[0065]

[0066] Table 2 Statistical table of H2S nucleophilic addition activity of different aryl nitrile substrates to prepare thio-benzamide of example 3 of the present application

[0067] Phenyl cyanide substrate Conversion (%) Selectivity (%) Benzo nitrile 98.0 95.0 p-Tolunitrile 94.8 92.5 p-Nitrobenzonitrile 90.5 88.9 4-Hydroxybenzonitrile 86.7 83.8 4-Methoxybenzonitrile 89.2 78.3 p-Cyanobenzaldehyde 85.6 80.9

[0068] As can be seen from the above, the In-doped carbon nitride polymers prepared by the present application at different calcination temperatures have good catalytic activity and product selectivity in the conversion of H2S to thio-benzamide by H2S nucleophilic addition of benzonitrile. Among them, the In 200 -NC sample has the highest catalytic activity. The prepared In-doped carbon nitride polymer material has a thin silk sheet layer morphology, high pore volume and specific surface area, low indium loading, can effectively catalyze the reaction of H2S conversion of benzonitrile, and has great industrial application prospect.

[0069] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. The use of an indium-based sulfur valorization catalyst in the H2S nucleophilic addition aryl nitrile group to thioaroyl amide reaction, characterized by: The preparation method of the indium-based sulfur high-value catalyst comprises the following steps: (1) grinding a nitrogen-containing precursor into powder, and polymerizing at high temperature to obtain a carbon nitride polymer: (2) dissolving the carbon nitride polymer in a solvent and ultrasonicating until completely dispersed; (3) dissolving a carbon source in a solvent and ultrasonicating until completely dissolved; (4) mixing the solutions of steps (2) and (3) and stirring uniformly at room temperature; (5) dissolving an indium source and a ligand compound in a solvent and stirring at room temperature; (6) mixing the solutions of steps (4) and (5), stirring, centrifuging, drying, grinding, and calcining to obtain the indium-based sulfur high-value catalyst; The carbon source is at least one of p-bromophenol, tetrabromobisphenol A, and tribromophenol; the molar ratio of the carbon source to the nitrogen-containing precursor is 1:1-3; The ligand compound is at least one of 1,10-phenanthroline, phthalocyanine, and Schiff base; the molar ratio of the indium source to the ligand compound is 1:1-2; The calcination temperature is 600-1000℃, the time is 2-8 h, the heating rate is 1-10℃ / min, and the atmosphere is one of nitrogen, ammonia, argon, and helium.

2. Use according to claim 1, characterized in that: The nitrogen-containing precursor is at least one of trichlorotriazine, thiocyanic acid, urea, dicyanamide, thiourea, and monocyamine.

3. Use according to claim 1, characterized in that: The indium source is at least one of indium chloride, indium nitrate, indium phosphide, indium bromide, and isopropyl alcohol indium.

4. Use according to claim 1, characterized in that: The solvent is at least one of deionized water, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, triethanolamine, isopropylamine, ethanol, methanol, ethylene glycol, and diethylamine.

5. The use according to claim 1, characterized in that: The polymerization temperature in step (1) is 400-600℃, and the heating rate is 1-5℃ / min.

6. Use according to claim 1, characterized in that: The drying temperature in step (6) is 80-120℃, and the time is 8-24 h.

7. Use according to claim 1, characterized in that: The indium-based sulfur high-value catalyst has a nanosieve carbon-nitrogen polymer as a carrier, and metal In is dispersed in the carrier in an atomic form; the doping amount of In in the catalyst is 1-4 wt.%, and the single-atom activity is In-N X , wherein 2 < X < 6; the specific surface area of the catalyst is 400-800 m 2 / g.

Images