A method for preparing a catalyst having an optimized platinum reaction site and applications thereof

Abstract

The present application relates to a kind of catalyst with optimized platinum reaction site and its preparation method, and application in the hydrogen production of photo-reforming lignocellulose.The present application finds that by adjusting acidification concentration, the regulation of platinum reaction site can be realized by a large number of researches, and the optimized reaction site can effectively lengthen H-OH bond for promoting hydrogen evolution process.The acidification strategy provided by the present application changes the complexation site between carrier and platinum ion by changing the properties of carrier, and anchors metal through three-dimensional mesoporous structure, which has excellent activity and stability, which is different from the reported scheme of optimizing platinum coordination structure to promote hydrogen evolution process, without additional introduction of ligand, which leads to cost increase, and ligand structure instability leads to poor cycle stability factors.The present application can not only be used to promote the hydrogen production of photo-reforming lignocellulose, but also has effective promoting effect on hydrogen production capacity of other substrates.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic material preparation and photocatalysis technology, specifically relating to a method for preparing a catalyst with optimized platinum reaction sites and its application in photo-reforming lignocellulose to produce hydrogen. Background Technology

[0002] Hydrogen (H2) is sustainable, clean, and has a high energy density (120 MJ·kg⁻¹). -1 Hydrogen is considered an important energy carrier in a sustainable energy economy. Solar-driven hydrogen production offers a promising and sustainable way to utilize solar energy. However, overall water splitting is often slowed down or even completely inhibited by oxygen evolution kinetics. Due to the lower reaction energy barrier of organic oxidation, replacing the oxygen evolution reaction with organic oxidation is a more efficient, economical, and environmentally friendly resource generation strategy.

[0003] Lignocellulose is an abundant, green, and renewable biomass resource that is attracting widespread attention. Converting lignocellulose into hydrogen evolution and producing valuable products is one of the important pathways to obtaining green energy in the future. However, thermal reforming processes are practically limited by energy consumption and carbon emissions. Photoreforming reactions can achieve highly selective conversion under mild conditions via redox species or reaction intermediates. However, photoreforming of lignocellulose faces three main bottlenecks: i) its stubborn structure and strong alkaline conditions are often necessary to achieve the optimal hydrogen evolution rate; ii) its complex structure and lack of specific reaction sites for selective conversion; and iii) rapid support recombination, necessitating the development of more effective lignocellulose reforming catalysts. Therefore, developing efficient and green photocatalysts for photoreforming lignocellulose under mild conditions is valuable and has broad application prospects.

[0004] Modification of co-catalysts in the photocatalytic hydrogen evolution reaction (HER) can significantly reduce overpotential, promote charge transfer, and provide additional adsorption activation sites, and is considered a good means to promote the HER process. Currently, platinum-based materials are the most active catalysts for the HER, due to the high work function of Pt forming a Schottky barrier that promotes irreversible electron transfer at the interface. Furthermore, the hydrogen adsorption free energy (ΔG) is a key factor influencing the HER process. H * This can reflect the adsorption and desorption process of hydrogen, when ΔG H * As the value approaches zero, HER becomes more effective, and based on the work of Nørskov et al., ΔG was established on the depositional surfaces of transition metals and noble metals. H * The DFT database was used, and the measured exchange current was used to calculate ΔG. H *A function was established, and a volcano-shaped curve was obtained, further demonstrating that Pt is the most effective hydrogen evolution catalyst. However, the content of platinum in the Earth's crust is only 0.001%, which undoubtedly leads to the problems of scarcity and high price. At the same time, highly dispersed platinum also faces the problem of easy agglomeration during photo-reforming.

[0005] Highly dispersible platinum catalysts using ligands are an effective and commonly used method to promote hydrogen evolution. However, they suffer from poor stability due to unstable anchoring relationships between ligands and platinum, and between coordination and the support. Obtaining highly stable, highly active, and controllable platinum catalysts through green and simple methods is extremely challenging. Summary of the Invention

[0006] The purpose of this invention is to solve the problems in the existing technology of photoreforming lignocellulose, which usually requires strong alkaline conditions to break the CC / CO bond, as well as the problems of platinum dispersion and easy agglomeration. Therefore, it provides a preparation method and application of optimized platinum reaction sites, which can be effectively used for photoreforming lignocellulose to produce hydrogen under neutral conditions, is non-corrosive to equipment, and the catalyst is easy to separate and has good photocatalytic stability.

[0007] To achieve the above objectives, the present invention is accomplished by the following means: A method for preparing a catalyst with optimized platinum reaction sites includes the following steps: (1) Add the acid to the three-dimensional titanate dispersion; (2) Platinum salt aqueous solution is added for complexation with three-dimensional titanates; (3) The product is obtained by high-temperature calcination.

[0008] Preferably, the acid in step (1) is selected from one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; more preferably, the acid is selected from hydrochloric acid.

[0009] Preferably, the concentration of the acid is 0.01-0.25 mol·L⁻¹. -1 More preferably, the concentration of the acid is 0.1 mol·L⁻¹. -1 .

[0010] Preferably, the three-dimensional titanate dispersion in step (1) is obtained by ultrasonic dispersion of three-dimensional titanate.

[0011] Preferably, the ultrasonic dispersion time is 20-60 min; more preferably, the ultrasonic dispersion time is 30 min.

[0012] Preferably, the three-dimensional titanate is prepared from N,N-dimethylformamide, tetrabutyl titanate, and alcohol; and / or from titanium metal salt and oxide; more preferably, the three-dimensional titanate is prepared from N,N-dimethylformamide, tetrabutyl titanate, and alcohol by hydrothermal method; and / or from titanium metal salt and oxide by alkaline hydrothermal method.

[0013] Preferably, the alcohol is selected from one or more of isopropanol and ethylene glycol.

[0014] Preferably, the mass ratio of N,N-dimethylformamide, tetrabutyl titanate, and alcohol is 1:0.05-0.3:1-6.

[0015] Preferably, the three-dimensional titanate is prepared by the following method: Tetrabutyl titanate was rapidly added to a mixed solution of N,N-dimethylformamide and alcohol, and then transferred to a reaction vessel for heating reaction.

[0016] Preferably, the reactor is selected from a reactor lined with tetrafluoroethylene.

[0017] Preferably, the heating reaction is carried out at a temperature of 140-220°C for 12-48 hours. Preferably, the platinum salt in step (2) is selected from one or more of platinum chloride, chloroplatinic acid, platinum acetylacetonate, and potassium chloroplatinate; more preferably, the platinum salt is selected from chloroplatinic acid.

[0018] Preferably, the platinum salt is selected from chloroplatinic acid hexahydrate.

[0019] Preferably, the concentration of the metal salt solution is 1-10 g / L; more preferably, the concentration of the metal salt solution is 4 g / L.

[0020] Preferably, the high-temperature calcination in step (3) is carried out at a temperature of 300-600℃ for 1-5 hours.

[0021] A second aspect of the present invention provides a catalyst with optimized platinum reaction sites prepared according to the above preparation method.

[0022] A third aspect of the present invention provides a method for optimizing platinum reaction sites in a platinum catalyst, comprising the following steps: (1) Add the acid to the three-dimensional titanate dispersion; (2) Platinum salt aqueous solution is added for complexation with three-dimensional titanates; (3) The product is obtained by high-temperature calcination.

[0023] Preferably, the acid in step (1) is selected from one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; more preferably, the acid is selected from hydrochloric acid.

[0024] Preferably, the concentration of the acid is 0.01-0.25 mol·L⁻¹. -1 More preferably, the concentration of the acid is 0.1 mol·L⁻¹. -1 .

[0025] Preferably, the three-dimensional titanate dispersion in step (1) is obtained by ultrasonic dispersion of three-dimensional titanate.

[0026] Preferably, the ultrasonic dispersion time is 20-60 min; more preferably, the ultrasonic dispersion time is 30 min.

[0027] Preferably, the three-dimensional titanate is prepared from N,N-dimethylformamide, tetrabutyl titanate, and alcohol; and / or from titanium metal salt and oxide; more preferably, the three-dimensional titanate is prepared from N,N-dimethylformamide, tetrabutyl titanate, and alcohol by hydrothermal method; and / or from titanium metal salt and oxide by alkaline hydrothermal method.

[0028] Preferably, the alcohol is selected from one or more of isopropanol and ethylene glycol.

[0029] Preferably, the mass ratio of N,N-dimethylformamide, tetrabutyl titanate, and alcohol is 1:0.05-0.3:1-6.

[0030] Preferably, the three-dimensional titanate is prepared by the following method: Tetrabutyl titanate was rapidly added to a mixed solution of N,N-dimethylformamide and alcohol, and then transferred to a reaction vessel for heating reaction.

[0031] Preferably, the reactor is selected from a reactor lined with tetrafluoroethylene.

[0032] Preferably, the heating reaction is carried out at a temperature of 140-220°C for 12-48 hours. Preferably, the platinum salt in step (2) is selected from one or more of platinum chloride, chloroplatinic acid, platinum acetylacetonate, and potassium chloroplatinate; more preferably, the platinum salt is selected from chloroplatinic acid.

[0033] Preferably, the platinum salt is selected from chloroplatinic acid hexahydrate.

[0034] Preferably, the concentration of the metal salt solution is 1-10 g / L; more preferably, the concentration of the metal salt solution is 4 g / L.

[0035] Preferably, the high-temperature calcination in step (3) is carried out at a temperature of 300-600℃ for 1-5 hours.

[0036] The fourth aspect of this invention provides the application of three-dimensional titanates in optimizing platinum reaction sites in platinum catalysts.

[0037] Preferably, the three-dimensional titanate is prepared from N,N-dimethylformamide, tetrabutyl titanate, and alcohol; and / or from titanium metal salt and oxide; more preferably, the titanate is prepared from N,N-dimethylformamide, tetrabutyl titanate, and alcohol by a hydrothermal method; and / or from titanium metal salt and oxide by an alkaline hydrothermal method.

[0038] Preferably, the alcohol is selected from one or more of isopropanol and ethylene glycol.

[0039] Preferably, the mass ratio of N,N-dimethylformamide, tetrabutyl titanate, and alcohol is 1:0.05-0.3:1-6.

[0040] Preferably, the three-dimensional titanate is prepared by the following method: Tetrabutyl titanate was rapidly added to a mixed solution of N,N-dimethylformamide and alcohol, and then transferred to a reaction vessel for heating reaction.

[0041] Preferably, the reactor is selected from a reactor lined with tetrafluoroethylene.

[0042] Preferably, the heating reaction is carried out at a temperature of 140-220°C for 12-48 hours. A fifth aspect of the present invention provides a method for photo-reforming lignin to produce hydrogen, comprising the following steps: taking the above-mentioned catalyst having optimized platinum reaction sites, lignocellulose substrate, and water, placing them in a photoreactor, and carrying out a reforming reaction under light irradiation.

[0043] Preferably, the lignocellulose substrate is selected from one or more of lignin, hemicellulose, cellulose, carbohydrate biomass, and lignin model compounds.

[0044] Preferably, the pH value of the water is 7.

[0045] Preferably, the mass ratio of the catalyst with optimized platinum reaction sites, the lignocellulose substrate, and water is 0.05:0.1:100.

[0046] Preferably, the light source is selected from one or more of sunlight, xenon lamp light source, and LED light source; most preferably, the light source is selected from sunlight simulated using a xenon lamp light source equipped with an AM 1.5G filter.

[0047] Preferably, the reforming reaction is carried out under closed inert gas and / or vacuum conditions.

[0048] Preferably, the inert gas is selected from one or more of nitrogen, helium, and argon.

[0049] The sixth aspect of the present invention provides the application of the above-mentioned catalyst with optimized platinum reaction sites in photo-reforming lignin for hydrogen production.

[0050] Compared with existing technologies, the present invention has the following advantages: (1) Through extensive research, this invention has discovered that platinum can be obtained by adjusting the concentration of acid. 平台 Hebo 台阶 / 扭结 For platinum reaction sites with coexisting reaction sites, the optimization effect on platinum reaction sites is best when the acid concentration is 0.1 mol / L, compared to platinum obtained without acid treatment. 台阶 / 扭结 At the reaction site, the H-OH bond of the water molecule is effectively elongated, thereby promoting the hydrogen evolution process.

[0051] (2) Based on this, the present invention uses titanate with a three-dimensional mesoporous structure to anchor platinum particles. On the one hand, the three-dimensional structure is conducive to obtaining a photocatalyst with a highly dispersed and highly stable embedded structure. On the other hand, due to its high work function, platinum will form a Schottky heterojunction with the three-dimensional mesoporous titanate, using the potential barrier to prevent electron and hole recombination and promote electron transfer. This will enable the catalyst to be effectively used in the photo-reforming of lignocellulose under mild and neutral conditions, overcoming the equipment corrosion caused by the use of strong alkali treatment in traditional technology and meeting the needs of green chemical industry.

[0052] (3) The photocatalyst with optimized platinum reaction sites obtained in this invention effectively improves the hydrogen production capacity of lignocellulose photo-reforming due to the optimization of platinum reaction sites and the three-dimensional mesoporous structure. At the same time, the lignocellulose is oxidized into high-value products, which is conducive to the sustainable high-value utilization of lignocellulose. Attached Figure Description

[0053] Figure 1 The carbon monoxide-infrared spectra of the three-dimensional Pt / TiO2 (0.1 M) catalyst in Example 1 and the three-dimensional Pt / TiO2 (0 M) catalyst in Comparative Example 1 are shown.

[0054] Figure 2 Scanning electron microscope (SEM) images of the three-dimensional Pt / TiO2 (0.1 M) catalyst in Example 1 and the two-dimensional Pt / TiO2 (0.1 M) catalyst in Comparative Example 3.

[0055] Figure 3The activity diagrams of the three-dimensional Pt / TiO2 (0.1 M) catalyst in Example 1, the three-dimensional Pt / TiO2 (0 M) catalyst in Comparative Example 1, the three-dimensional Pt / TiO2 (0.01 M) catalyst in Comparative Example 2, the three-dimensional Pt / TiO2 (0.05 M) catalyst in Comparative Example 2, and the three-dimensional Pt / TiO2 (0.25 M) catalyst in Comparative Example 2 under simulated sunlight for reforming 4-methylbenzyl alcohol to produce hydrogen.

[0056] Figure 4 For platinum reaction sites (platinum) 平台 Hebo 台阶 / 扭转 Theoretical calculation diagram showing the effect of H-OH bond length on water molecules.

[0057] Figure 5 The activity diagrams show the reforming of 4-methylbenzyl alcohol to produce hydrogen under simulated sunlight for the two-dimensional-Pt / TiO2 (0.1 M) catalyst in Comparative Example 3 and the three-dimensional-Pt / TiO2 (0.1 M) catalyst in Example 1.

[0058] Figure 6 The activity diagram of the three-dimensional Pt / TiO2 (0.1 M) catalyst prepared in Example 1 for hydrogen production by reforming different types of biomass substrates under simulated sunlight is shown.

[0059] Figure 7 The diagram shows the cyclic stability of the three-dimensional Pt / TiO2 (0.1 M) catalyst prepared in Example 1 for hydrogen production by reforming 4-methylbenzyl alcohol under simulated sunlight. Detailed Implementation

[0060] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0061] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0062] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0063] Example 1 A catalyst with optimized platinum reaction sites, the preparation method of which includes the following steps: (1) Titanium isopropoxide (0.83 g) was rapidly added to a mixed solution of isopropanol (19.64 g) and N,N-dimethylformamide (7.84 g). The transparent solution was transferred to a 50 mL stainless steel autoclave lined with polytetrafluoroethylene and kept in an oven at 200 °C for 24 hours to obtain a three-dimensional titanium salt.

[0064] (2) The three-dimensional titanate (0.1g) was ultrasonically dispersed in HCl aqueous solution (10mL, 0.1M), and then chloroplatinic acid aqueous solution was added for complexation. After stirring for two hours, the suspension was collected by centrifugation and pyrolyzed into Pt / TiO2 by calcination at 450℃ for 2 hours under H2 / Ar atmosphere. It was named three-dimensional-Pt / TiO2 (0.1M).

[0065] Comparative Example 1 A platinum catalyst, the preparation method of which includes the following steps: (1) Titanium isopropoxide (0.83 g) was rapidly added to a mixed solution of isopropanol (19.64 g) and N,N-dimethylformamide (7.84 g). The transparent solution was transferred to a 50 mL stainless steel autoclave lined with polytetrafluoroethylene and kept in an oven at 200 °C for 24 hours to obtain a three-dimensional titanium salt.

[0066] (2) The three-dimensional titanate (0.1g) was ultrasonically dispersed into an aqueous solution (10mL), and then chloroplatinic acid aqueous solution was added for complexation. After stirring for two hours, the suspension was collected by centrifugation and pyrolyzed into Pt / TiO2 by calcination at 450℃ for 2 hours under H2 / Ar atmosphere. It was named three-dimensional-Pt / TiO2 (0M).

[0067] Comparative Example 2 A catalyst with optimized platinum reaction sites on a three-dimensional titanate substrate, exhibiting a coexistence of plateaus and steps / torsions, is prepared by the following steps: (1) Titanium isopropoxide (0.83 g) was rapidly added to a mixed solution of isopropanol (19.64 g) and N,N-dimethylformamide (7.84 g). The transparent solution was transferred to a 50 mL stainless steel autoclave lined with polytetrafluoroethylene and kept in an oven at 200 °C for 24 hours to obtain a three-dimensional titanium salt.

[0068] (2) Three-dimensional titanate (0.1 g) was ultrasonically dispersed into HCl aqueous solution (10 mL, x M) with different concentrations, and then chloroplatinic acid aqueous solution was added for complexation coordination. After stirring for two hours, the suspension was collected by centrifugation and pyrolyzed into Pt / TiO2 by calcination at 450℃ for 2 hours under H2 / Ar atmosphere. It was named three-dimensional-Pt / TiO2 (x M), specifically x = 0.01, 0.05 or 0.25.

[0069] Comparative Example 3 A catalyst with optimized platinum reaction sites on two-dimensional titanates, exhibiting a coexistence of plateaus and steps / torsions, is prepared by the following steps: TiO2 (P25, 1g) was added to a NaOH aqueous solution (30mL, 10M), and stirred for 20min. The white suspension was then transferred to a 50mL stainless steel autoclave lined with polytetrafluoroethylene and kept in an oven at 180℃ for 72h to obtain a two-dimensional titanate. The surface NaOH was removed by washing with water, and the resulting white solid was vacuum dried at 60℃ for 12h.

[0070] Two-dimensional titanate (0.1 g) was ultrasonically dispersed in HCl aqueous solution (10 mL, 0.1 M), and then chloroplatinic acid aqueous solution was added for complexation coordination. After stirring for two hours, the suspension was collected by centrifugation and pyrolyzed by calcination at 450 °C for 2 hours under H2 / Ar atmosphere to convert it into Pt / TiO2, named two-dimensional-Pt / TiO2 (0.1 M).

[0071] Verification Example 1 The catalyst prepared in Example 1 with optimized platinum reaction sites of both plateau and step / torsion coexistence (three-dimensional-Pt / TiO2 (0.1M)) and the catalyst prepared in Comparative Example 1 with optimized platinum reaction sites of step / torsion (three-dimensional-Pt / TiO2 (0M)) were used to test their platinum coordination state using a carbon monoxide-infrared spectroscopy device. The test results are as follows: Figure 1 As shown. The results show that, compared to Comparative Example 1, after the introduction of acid, the reaction sites of platinum in Example 1 changed from a step / twist state to a state of both plateau and step / twist coexistence. The morphological structures of Example 1 and Comparative Example 3 after calcination were investigated using scanning electron microscopy, as shown. Figure 2 As shown, the results indicate that the calcined samples maintained the precursor structure. Example 1 consisted of spheres with a three-dimensional mesoporous structure, while Comparative Example 3 consisted of two-dimensional nanowires. The abundant mesoporous structure of Example 1 facilitated the adsorption and diffusion processes of the reaction substrate.

[0072] Verification Example 2 50 mg of the three-dimensional Pt / TiO2 (0.1 M) catalyst from Example 1, 50 mg of the three-dimensional Pt / TiO2 (0 M) catalyst from Comparative Example 1, 50 mg of the three-dimensional Pt / TiO2 (0.01 M) catalyst from Comparative Example 2, 50 mg of the three-dimensional Pt / TiO2 (0.05 M) catalyst from Comparative Example 2, and 50 mg of the three-dimensional Pt / TiO2 (0.25 M) catalyst from Comparative Example 2, along with 0.5 g of 4-methylbenzyl alcohol and 100 mL of water, were added to the photoreactor. The pH was adjusted to 7, and the reaction was carried out under simulated sunlight for 4 hours in a sealed argon atmosphere. 1 mL of gas was sampled at 1-hour intervals and analyzed qualitatively and quantitatively using gas chromatography. Each experiment was repeated five times, and the average value was used for analysis. The analytical results are as follows: Figure 3 As shown.

[0073] like Figure 3 The results showed that, compared to the hydrogen production rate of cellulose photoreforming using only a three-dimensional TiO2 catalyst (only 165 μmol·g), the hydrogen production rate of cellulose photoreforming was significantly higher. -1 ·h -1 After platinum loading, the hydrogen evolution rate was effectively promoted, fully demonstrating the electron transfer ability of platinum's high work function. The hydrogen evolution rates at different platinum reaction sites were as follows: When the reaction sites in Comparative Example 1 only had step / torsion sites, the hydrogen evolution rate reached 1621.6 μmol·g. -1 ·h -1 When the platinum reaction sites consist of both plateau and step / torsion coexistence (Example 1, Comparative Example 2), the hydrogen evolution activity of the three-dimensional Pt / TiO2 (0.01M) catalyst in Comparative Example 2 increased to 3077.9 μmol·g. -1 ·h -1 In Comparative Example 2, the hydrogen evolution activity of the three-dimensional Pt / TiO2 (0.05 M) catalyst was increased to 3319.0 μmol·g. -1 ·h -1 In Example 1, the hydrogen evolution activity of the three-dimensional Pt / TiO2 (0.1M) catalyst was increased to 4654.7 μmol·g. -1 ·h -1 In Comparative Example 2, the hydrogen evolution activity of the three-dimensional Pt / TiO2 (0.25 M) catalyst was increased to 2366.7 μmol·g. -1 ·h -1 .like Figure 4 As shown, water molecules in platinum 台阶 / 扭转 The H-OH bond length at the site is 1.000 Å, which is significant in platinum. 平台 The H-OH bond length at the site increased from 1.000 Å to 1.114 Å, which means that in platinum... 平台The H-OH bonds at the reaction sites are more easily broken, which is the main reason for the improved hydrogen evolution activity. The above results indicate that acidification can adjust the platinum reaction sites to obtain better hydrogen evolution activity. Subsequently, the catalytic activity of the two-dimensional Pt / TiO2 (0.1M) catalyst prepared in Comparative Example 3 for reforming 4-methylbenzyl alcohol to produce hydrogen was compared under simulated sunlight, and the results are as follows: Figure 5 As shown, the hydrogen evolution rate for hydrogen production from 4-methylbenzyl alcohol via two-dimensional Pt / TiO2 (0.1 M) reforming is 1402.9 μmol·g. -1 ·h -1 The hydrogen evolution rate for hydrogen production from 4-methylbenzyl alcohol via three-dimensional Pt / TiO2 (0.1M) reforming was 4656.0 μmol·g. -1 ·h -1 Three-dimensional mesoporous structures facilitate rapid product adsorption and desorption processes, resulting in excellent hydrogen evolution rates.

[0074] Subsequently, the catalytic activity of the three-dimensional Pt / TiO2 (0.1M) catalyst prepared in Example 1 in the hydrogen production from different types of biomass substrates (glucose, xylose, 4-methylbenzyl alcohol, cellulose, hemicellulose, lignin) under simulated sunlight was tested. Figure 6 The results showed that the hydrogen evolution activities reached 4771.3, 4681.9, 4654.7, 1450.5, 3423.0, and 614.9 μmol·g, respectively. -1 ·h -1 The above results indicate that the three-dimensional Pt / TiO2 (0.1 M) is an effective hydrogen evolution catalyst, superior to most reported systems in neutral environments. This can be attributed to the optimization of platinum reaction sites and the synergistic effect of the three-dimensional structure.

[0075] Furthermore, the cycle stability of the three-dimensional Pt / TiO2 (0.1M) catalyst prepared in Example 1 for reforming 4-methylbenzyl alcohol to produce hydrogen under simulated sunlight was tested, specifically including the following steps: 50 mg of the three-dimensional Pt / TiO2 (0.1 M) catalyst prepared in Example 1 was added to the photoreactor along with 0.5 g of methylbenzyl alcohol and 100 mL of water. The pH was adjusted to 7, and the reaction was carried out under nitrogen atmosphere and simulated sunlight for 4 hours. After the reaction, 1 mL of the gas was collected and analyzed qualitatively and quantitatively by gas chromatography. Every 4 hours, the generated gas was removed using inert gas, and the next round of stability testing was conducted. The test results are as follows: Figure 7 As shown in the figure. The results show that after 6 cycles, the hydrogen production capacity of the three-dimensional-Pt / TiO2 (0.1M) catalyst for photo-reforming 4-methylbenzyl alcohol did not change significantly, indicating that the three-dimensional-Pt / TiO2 (0.1M) catalyst has good photostability, which is promising for realizing the high-value utilization of lignocellulose.

[0076] The above detailed embodiments provide a specific description of the technical solutions involved in this invention. It should be noted that the above description is only intended to help those skilled in the art better understand the methods and ideas of this invention, and is not intended to limit the scope of the invention. Without departing from the principles of this invention, those skilled in the art can make appropriate adjustments or modifications to this invention, and such adjustments and modifications should also fall within the protection scope of this invention.

Claims

1. A method for preparing a catalyst having platinum reaction sites, characterized in that, The steps include the following: (1) Add the acid to the three-dimensional titanate dispersion; the concentration of the acid is 0.01-0.25 mol·L. -1 The three-dimensional titanate was prepared by rapidly adding tetrabutyl titanate to a mixed solution of N,N-dimethylformamide and an alcohol, and then transferring it to a reaction vessel for heating reaction; the alcohol was selected from one or more of isopropanol and ethylene glycol. (2) Platinum salt aqueous solution is added for complexation with three-dimensional titanates; (3) The product is obtained by high-temperature calcination under H2 / Ar atmosphere; the high-temperature calcination temperature is 300-600℃. The platinum reaction site is specifically platinum. 平台 Hebo 台阶 / 扭结 Reaction site.

2. The preparation method according to claim 1, characterized in that, The acid mentioned in step (1) is selected from one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

3. The preparation method according to claim 1, characterized in that, The mass ratio of N,N-dimethylformamide, tetrabutyl titanate, and alcohol is 1:0.05-0.3:1-6.

4. The preparation method according to any one of claims 1-3, characterized in that, The high-temperature calcination time in step (3) is 1-5 hours.

5. A catalyst having platinum reaction sites prepared by the preparation method according to any one of claims 1-4.

6. The application of the catalyst with platinum reaction sites according to claim 5 in photo-reforming lignin for hydrogen production.

7. A method for photo-reforming lignin to produce hydrogen, comprising the following steps: taking a catalyst having platinum reaction sites as described in claim 5, a lignocellulose substrate, and water, placing them in a photoreactor, and carrying out a reforming reaction under light irradiation.

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