Application of a Palladium-Doped Nanoporous Nickel / Nickel Oxide Composite Material in the Catalytic Hydrogenation Reaction of p-Nitrophenol

Abstract

The present invention discloses the application of a palladium-doped nanoporous nickel / nickel oxide composite material in the catalytic hydrogenation reaction of p-nitrophenol. The palladium-doped nanoporous nickel / nickel oxide composite material is directly obtained through chemical corrosion of an AlNiPd alloy strip. The composite material has a three-dimensionally interconnected porous structure, and palladium is dispersed in the nickel / nickel oxide matrix at the sub-nanometer scale. The material exhibits excellent solution catalytic hydrogenation activity and can achieve the hydrogenation reduction reaction of substrates with sodium borohydride solutions of different concentrations. Therefore, the material involved in this patent is simple to prepare, has outstanding catalytic hydrogenation reaction activity, and has good application prospects in the fields of p-nitrophenol wastewater treatment and p-aminophenol preparation.

Description

Technical Field

[0001] The present invention relates to the application of a palladium-doped nanoporous nickel / nickel oxide composite material in the catalytic hydrogenation reaction of p-nitrophenol, belonging to the field of catalytic materials. Background Art

[0002] p-Nitrophenol is an important raw material or intermediate, playing an important role in industrial production such as medicine, dyes, developing agents, pesticides, etc. However, p-nitrophenol is a toxic and harmful environmental pollutant, and reducing this wastewater is an important way to degrade pollutants. At the same time, p-aminophenol is an important fine chemical product, mainly used for manufacturing antipyretic and analgesic drugs, manufacturing sulfur dyes, and synthesizing stabilizers for polymer materials, etc. Currently, the annual output of p-aminophenol is about 200,000 tons. With the growth of economic society and health needs, the market prospect of p-aminophenol is broad. Therefore, from the perspectives of environmental protection technology and organic matter production, the hydrogenation of p-nitrophenol to prepare p-aminophenol has important practical significance.

[0003] The reduction of p-nitrophenol with iron powder under acidic conditions is a traditional production method for preparing p-aminophenol, but it has a low yield, there are problems of a large amount of iron mud and wastewater treatment, and it is easy to cause environmental pollution. The catalytic hydrogenation method is a more environmentally friendly method for the reduction of p-nitrophenol and the production of p-aminophenol. Among them, the catalyst has a key influence on the catalytic hydrogenation reaction rate of p-nitrophenol. The reported catalysts are mainly based on noble metals, such as hierarchical porous zeolites modified with PtRu alloy nanoparticles (CN201711030384.1), gold nanoparticle / metal-organic framework composites (CN 202010047881.8), palladium / molybdenum carbide composites (CN 202110535307.1), etc. These catalytic materials show outstanding catalytic performance in the reduction reaction of p-nitrophenol, but the cost is still high, which is not conducive to large-scale use. The exploration of transition metal (Fe, Co, Ni, Cu, etc.) catalysts has made great progress, but improving their catalytic performance is still a challenge (Chem.Rev.2019,119,2611-2680.).

[0004] Therefore, for the catalytic hydrogenation reaction of p-nitrophenol, exploring the preparation of a catalytic system with high activity and low cost has important scientific significance and practical value. Reducing the dosage of noble metals and simultaneously improving the catalytic reaction activity is the key to the application of the hydrogenation reaction of p-nitrophenol. Summary of the Invention

[0005] Aiming at the deficiencies existing in the traditional hydrogenation reaction system of p-nitrophenol solution, the present invention discloses a method for using a palladium-doped nanoporous nickel / nickel oxide composite material to catalyze the hydrogenation reaction of p-nitrophenol.

[0006] The present invention is realized through the following technical solutions:

[0007] A method for catalytic hydrogenation reaction of p-nitrophenol, which ultrasonically disperses a catalyst in water, takes an appropriate amount and adds it to a mixed solution of p-nitrophenol and sodium borohydride to make the reaction proceed until the solution completely fades. It is characterized in that the catalyst is a palladium-doped nanoporous nickel / nickel oxide composite material.

[0008] The palladium-doped nanoporous nickel / nickel oxide composite material has a three-dimensionally interconnected porous structure.

[0009] In the palladium-doped nanoporous nickel / nickel oxide composite material, palladium is dispersed in the nickel / nickel oxide matrix at a sub-nanometer scale.

[0010] The preparation process of the palladium-doped nanoporous nickel / nickel oxide composite material includes the following steps:

[0011] (1) Preparation of alloy strip: Melting nickel, palladium, and aluminum metals to obtain an AlNiPd alloy ingot, and performing melt spinning to obtain an alloy strip;

[0012] (2) Corrosion of alloy strip: Chemically corroding the strip obtained in step (1) to obtain a palladium-doped nanoporous nickel / nickel oxide composite material.

[0013] Further, in step (1), according to the ratio of Al 90 Ni x Pd y (x = 9 - 9.9, y = 0.1 - 1), the composition of the AlNiPd alloy is Al 90 Ni x Pd y (x = 9 - 9.9, y = 0.1 - 1).

[0014] Further, in step (1), the spinning rate is 1000 - 5000 rpm, preferably 2000 - 3000 rpm.

[0015] Further, in step (2), the chemical corrosion is to place the strip in a strong base solution until the reaction is complete.

[0016] Further, the strong base solution is a 1 - 3M aqueous solution of sodium hydroxide or potassium hydroxide, and the reaction time is 12 - 24 hours.

[0017] Further, after the composite material is prepared, it is ultrasonically dispersed in water to obtain a catalyst dispersion liquid with a content of 2 - 5 mg / mL, preferably 4 mg / mL.

[0018] Further, the dosage of the catalyst dispersion liquid is 0.005 - 0.02 mL, preferably 0.01 mL.

[0019] Further, in the method for catalytic hydrogenation of p-nitrophenol, the ratio of p-nitrophenol to sodium borohydride is 1:10 to 1:1000.

[0020] Preferably, the ratio of p-nitrophenol to sodium borohydride is 1:100 to 1:1000.

[0021] Adopting the above technical solution, the material change involved in the present invention is as follows:

[0022] According to the Al-Ni binary phase diagram, the alloy strip mainly contains the metal Al phase and the Al3Ni phase. Pd is dissolved in the alloy matrix through Pd-Al and Pd-Ni metal interactions. During the strong alkali corrosion process, the metal Al phase is corroded first to form a primary pore structure, and then the Al in the Al3Ni phase is corroded to form a secondary pore structure. At the same time, part of the surface layer Ni is oxidized to NiO. Pd is combined with Ni in the Ni phase through Pd-Ni interaction and combined with O in NiO through Pd-O interaction.

[0023] In the solution hydrogenation catalytic reaction, the p-nitrophenol solution and the sodium borohydride solution are mixed evenly, and the solution shows a light yellow color, which is the absorption spectrum characteristic of p-nitrophenol under weak alkaline conditions; 10 μL of the aqueous dispersion of palladium-doped nanoporous nickel / nickel oxide composite material is added and stirred evenly. On the surface of the catalyst, p-nitrophenol combines with the active hydrogen intermediate released by sodium borohydride, and the nitro group is reduced. p-Nitrophenol is converted into p-aminophenol, and the solution becomes colorless.

[0024] Adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0025] Considering from the aspect of material preparation, the preparation of the sub-nanoscale palladium-doped composite catalyst involved in this patent has its characteristics. Compared with other disclosed methods, such as the Pd-doped carbon material obtained by the thermal cracking method (CN201910851330.4), the single-atom doped tin oxide material obtained by the hydrothermal reaction (CN 202110087661.2), the single-atom modified manganese dioxide / carbon nanotube composite material and two-dimensional nickel telluride obtained by solution impregnation adsorption and high-temperature annealing (CN201810181736.1 and CN202011360684.8), and the AgPd single-atom alloy material obtained by the multiple corrosion method (CN 202210862058.1), this patent directly obtains the sub-nanoscale palladium-doped Ni / NiO composite material through the corrosion of aluminum alloy. The method is simple and can meet the requirements of batch production.

[0026] From the perspective of catalytic applications, the palladium-doped composite catalyst involved in this patent has a synergistic effect of components and structure. The nanoporous structure has sufficient active sites exposed; palladium is doped at the sub-nanometer scale, significantly improving the electronic structure of catalytic sites and enhancing the intrinsic catalytic activity; the Ni / NiO composite matrix helps to anchor palladium atoms to maintain the catalyst stability; the presence of NiO makes the catalyst surface hydrophilic, thus achieving a good dispersion effect in the solution, promoting the adsorption of p-nitrophenol and active hydrogen intermediates, and promoting the efficient progress of the reduction reaction. The above factors together achieve excellent solution hydrogenation catalytic effects and enable continuous and efficient hydrogenation reactions in the solution.

[0027] Therefore, the catalytic hydrogenation application of the composite material of the present invention has significant novelty, creativity and practicality. Brief Description of the Drawings

[0028] Figure 1 is Al 90 Ni 9.9 Pd 0.1 XRD patterns of alloy (a) and nanoporous Pd1@Ni / NiO composite material (b);

[0029] Figure 2 is the scanning electron microscope (SEM) image of nanoporous Pd1@Ni / NiO;

[0030] Figure 3 is the transmission electron microscope (TEM) image (a) and high-angle annular dark-field scanning image (b) of nanoporous Pd1@Ni / NiO;

[0031] Figure 4 is Al 90 Ni9Pd1 alloy (a) and nanoporous Pd 10 @Ni / NiO composite material (b) XRD patterns;

[0032] Figure 5 is nanoporous Pd 10 @Ni / NiO scanning electron microscope (SEM) image;

[0033] Figure 6 is the absorption spectrum change of the hydrogenation reaction of nitrophenol without catalyst (p-nitrophenol:sodium borohydride = 1:100);

[0034] Figure 7 is the absorption spectrum change of the hydrogenation reaction catalyzed by nanoporous Pd1@Ni / NiO (p-nitrophenol:sodium borohydride = 1:100);

[0035] Figure 8is the absorption spectrum change of the catalytic hydrogenation reaction of nanoporous Pd1@Ni / NiO (p-nitrophenol:sodium borohydride = 1:1000);

[0036] Figure 9 is nanoporous Pd 10 @Ni / NiO catalytic hydrogenation reaction absorption spectrum change (p-nitrophenol:sodium borohydride = 1:100);

[0037] Figure 10 is the absorption spectrum change of the catalytic hydrogenation reaction of nanoporous Ni / NiO (p-nitrophenol:sodium borohydride = 1:100). Detailed implementation mode

[0038] To make the objectives, technical solutions and beneficial effects of the present invention clearer, the present invention will be further described below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0039] Example 1 Preparation of nanoporous Pd1@Ni / NiO composite material

[0040] High-purity Al, Ni, and Pd are uniformly melted in a vacuum arc furnace according to the composition ratio of Al 90 Ni 9.9 Pd 0.1 to obtain a master alloy ingot; the master alloy is made into a strip at a rate of 2000 rpm in a strip casting machine. By chemical dealloying, the obtained strip is reacted in a sufficient amount of 1M KOH solution for 12 hours respectively, and the Al metal is corroded to obtain black powder.

[0041] XRD test shows that the Al 90 Ni 9.9 Pd 0.1 alloy contains a metal Al phase and a weak Al3Ni phase (as shown in Appendix Figure 1 a); after corrosion, the obtained product Pd1@Ni / NiO presents a Ni / NiO mixed phase (as shown in Appendix Figure 1 b), and no metal Pd phase appears, indicating that Pd is dispersed in the Ni / NiO matrix. Scanning electron microscope (SEM) test shows that the obtained material has a nanoporous structure (as shown in Appendix Figure 2 ); Transmission electron microscope (TEM) test further confirms the existence of the porous structure, and there is a three-dimensional through and uniform pore distribution (as shown in Appendix Figure 3 a), and Pd (the white part in the figure) is doped in the Ni / NiO matrix in a highly dispersed form at the sub-nanometer scale (as shown in Appendix Figure 3 b).

[0042] Example 2 Nanoporous Pd 10 Preparation of @Ni / NiO Composite Material

[0043] High-purity Al, Ni, and Pd were melted uniformly in a vacuum arc furnace according to the composition ratio of Al 90 Ni9Pd1 to obtain a master alloy ingot; the master alloy was made into strips at a rate of 2000 rpm in a melt spinner. By chemical dealloying, the obtained strips were reacted in a sufficient amount of 1 M KOH solution for 12 hours respectively, and the Al metal was corroded to obtain black powder.

[0044] XRD test showed that Al 90 Ni9Pd1 alloy contained metal Al phase and Al3Ni phase (as shown in Attachment Figure 4 a). After corrosion, the obtained product Pd 10 @Ni / NiO presented a Ni / NiO mixed phase (as shown in Attachment Figure 4 b), and no phase of metallic Pd appeared, indicating that Pd was dispersed in the Ni / NiO matrix. Scanning electron microscope (SEM) test showed that the obtained material had a nanoporous structure (as shown in Attachment Figure 5 ).

[0045] Example 3 Catalytic Hydrogenation Reaction of Sodium Borohydride by Nanoporous Pd1@Ni / NiO Composite Material (1:100)

[0046] 1 mL of p-nitrophenol solution (0.10 mM) was mixed evenly with 1 mL of sodium borohydride solution (10 mM, 1:100), and the solution showed light yellow; 10 μL of the aqueous dispersion (4 mg / mL) of nanoporous Pd1@Ni / NiO composite material was added, and stirring was carried out until the reaction proceeded until the solution completely faded.

[0047] The change of the solution absorption spectrum was recorded by an ultraviolet-visible spectrophotometer. The solution without adding the catalyst did not fade in two hours (as shown in Attachment Figure 6 ), and after adding the catalyst, the solution faded rapidly within a few minutes (as shown in Attachment Figure 7 ), indicating that the catalyst had excellent catalytic hydrogenation reaction activity.

[0048] Example 4 Catalytic Hydrogenation Reaction of Sodium Borohydride by Nanoporous Pd1@Ni / NiO Composite Material (1:1000)

[0049] 1 mL of p-nitrophenol solution (0.10 mM) was mixed evenly with 1 mL of sodium borohydride solution (100 mM, 1:1000), and the solution showed light yellow; 10 μL of the aqueous dispersion (4 mg / mL) of nanoporous Pd1@Ni / NiO composite material was added, and stirring was carried out until the reaction proceeded until the solution completely faded.

[0050] The change in the absorption spectrum of the solution was recorded by an ultraviolet-visible spectrophotometer. After the addition of the catalyst, the solution quickly reacted and faded (as shown in the attachment). Figure 8 This further indicates that the catalyst has excellent catalytic hydrogenation activity.

[0051] Example 5: Nano-porous Pd 10 Catalytic hydrogenation reaction of sodium borohydride by @Ni / NiO composite (1:100)

[0052] 1 mL of p-nitrophenol solution (0.10 mM) was mixed evenly with 1 mL of sodium borohydride solution (10 mM, 1:100), and the solution showed a light yellow color. 10 μL of the aqueous dispersion (4 mg / mL) of the nano-porous Pd 10 @Ni / NiO composite was added, and the reaction was stirred until the solution completely faded.

[0053] The change in the absorption spectrum of the solution was recorded by an ultraviolet-visible spectrophotometer. After the addition of the catalyst, the solution quickly reacted and faded (as shown in the attachment). Figure 9 This indicates that the catalyst has outstanding catalytic hydrogenation activity.

[0054] Comparative Example 1: Catalytic hydrogenation reaction of sodium borohydride by nano-porous Ni / NiO composite (1:100)

[0055] High-purity Al and Ni were melted evenly in a vacuum arc furnace according to the composition ratio of Al 90 Ni 10 to obtain a master alloy ingot; the master alloy was made into a strip at a rate of 2000 rpm in a strip casting machine. Dealloying was carried out by a chemical method, and the obtained strip was reacted in a sufficient amount of 1 M KOH solution for 12 hours respectively, and the Al metal was corroded to obtain Ni / NiO black powder.

[0056] 1 mL of p-nitrophenol solution (0.10 mM) was mixed evenly with 1 mL of sodium borohydride solution (10 mM, 1:100), and the solution showed a light yellow color. 10 μL of the aqueous dispersion (4 mg / mL) of the nano-porous Ni / NiO composite was added, and the reaction was stirred until the solution significantly faded.

[0057] The change in the absorption spectrum of the solution was recorded by an ultraviolet-visible spectrophotometer. After the addition of the catalyst, the solution faded slowly (as shown in the attachment). Figure 10 This indicates that the material does not have outstanding catalytic hydrogenation activity.

[0058] As can be seen from the above results, the obtained nanoporous Pd@Ni / NiO composite material has catalytic hydrogenation activity for p-nitrophenol and excellent catalytic effects on sodium borohydride solutions with different concentrations. From the comparative examples, it can be seen that the introduction of Pd plays an important promoting role in the hydrogenation reduction reaction of p-nitrophenol.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for catalytic hydrogenation reaction of p-nitrophenol. An appropriate amount of catalyst dispersion is added to a mixed solution of p-nitrophenol and sodium borohydride, and stirring is carried out to make the reaction proceed until the solution completely fades. It is characterized in that, The catalyst is a palladium-doped nanoporous nickel / nickel oxide composite material; In the composite material, palladium is dispersed in the nickel / nickel oxide matrix at the sub-nanometer scale, and its preparation process includes the following steps: (1)Preparation of alloy strip: According to the ratio of Al 90 Ni x Pd y (x = 9 - 9.9, y = 0.1 - 1), nickel, palladium, and aluminum metals are melted to obtain an AlNiPd alloy ingot, and then melt spinning is carried out to obtain an alloy strip; (2) Alloy strip corrosion: Chemically corrode the strip obtained in step (1) to obtain a palladium-doped nanoporous nickel / nickel oxide composite material.

2. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 1, wherein The composite material has a three-dimensionally interconnected porous structure.

3. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 1, wherein In step (1), the spinning rate is 1000 - 5000 rpm.

4. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 3, characterized in that, The spinning rate is 2000 - 3000 rpm.

5. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 1, wherein In step (2), the chemical corrosion is to place the strip in a strong base solution until the reaction is complete.

6. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 5, wherein, The strong base solution is a 1 - 3 M aqueous solution of sodium hydroxide or potassium hydroxide, and the reaction time is 12 - 24 hours.

7. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 1, characterized in that, The composite material is ultrasonically dispersed in water at a content of 2 - 5 mg / mL.

8. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 1, characterized in that, The dosage of the catalyst dispersion is 0.005 - 0.02 mL.

9. The method for catalytic hydrogenation reaction of p-nitrophenol according to claim 1, wherein The concentration ratio of p-nitrophenol to sodium borohydride is 1:10~1:1000.

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