Preparation method of supported PdAg nano material containing Ce < 3 + >

Abstract

The invention relates to the technical field of nano material preparation, in particular to a preparation method of a Ce < 3 + >-containing supported PdAg nano material, which comprises the following steps: carrying out first mixing, rotary evaporation treatment, plasma treatment, washing treatment and drying treatment on a cerium salt material and an active carrier material in a first solvent to obtain a carrier; carrying out second mixing on a carrier and a coupling agent in a second solvent to obtain a second mixed solution; adding a palladium salt material and a silver salt material into the second mixed solution for third mixing to obtain a third mixed solution; and a reducing agent is added into the third mixed solution for reduction, and the Ce < 3 + >-containing supported PdAg nano material is obtained. According to the method, the amorphous carrier rich in Ce < 3 + > can be rapidly prepared, uniform loading of PdAg nano-particles is achieved through plasma activation and coupling agent regulation and control, and the nano-material shows higher activity, excellent selectivity and good stability in formic acid dehydrogenation reaction.

Description

Technical Field

[0001] This invention relates to the field of nanomaterial preparation technology, specifically to a Ce-containing nanomaterial... 3+ A method for preparing supported PdAg nanomaterials. Background Technology

[0002] Hydrogen energy, as a clean and efficient energy form, has enormous development potential. Formic acid, as an emerging liquid hydrogen storage material, offers higher hydrogen storage density, milder storage and transportation conditions, controlled hydrogen release, and sustainability compared to traditional hydrogen storage methods. It provides a safer and more efficient solution for promoting the hydrogen economy, and is particularly suitable for distributed energy systems and mobile applications. With breakthroughs in catalyst technology and recycling systems, it is expected to become a core choice for next-generation hydrogen storage materials, with the key lying in the development of high-performance catalysts.

[0003] Acidic oxides are beneficial for the dehydration of formic acid, while basic oxides are beneficial for its dehydrogenation. Cerium oxide, as a typical basic metal oxide, is used for formic acid dehydrogenation. However, cerium oxide has a relatively low specific surface area and poor mass transfer efficiency, limiting its catalytic activity. Noble metal nanomaterials, due to their excellent catalytic activity and selectivity, are used in the field of hydrogen energy utilization. However, the preparation of noble metal nanomaterials generally suffers from problems such as easy agglomeration of metal particles, difficulty in precise size control, and insufficient metal dispersion, resulting in their catalytic performance not being fully realized. Summary of the Invention

[0004] (a) Purpose of the invention The purpose of this invention is to provide a Ce-containing 3+ The method for preparing supported PdAg nanomaterials can rapidly produce amorphous nanomaterials rich in Ce. 3+ The carrier is used to achieve uniform loading of PdAg nanoparticles through plasma activation and coupling agent regulation, so that the nanomaterials exhibit higher activity, excellent selectivity and good stability in the formic acid dehydrogenation reaction.

[0005] (II) Technical Solution To address the above problems, the present invention provides a Ce-containing... 3+ The preparation method of supported PdAg nanomaterials includes: The cerium salt material and the active carrier material are first mixed in a first solvent to obtain a first mixture; The first mixture was subjected to rotary evaporation to obtain precursor powder; The precursor powder was subjected to plasma treatment, washing treatment and drying treatment in sequence to obtain a carrier; The carrier and coupling agent are mixed a second time in a second solvent to obtain a second mixture; Palladium salt material and silver salt material are added to the second mixture for a third mixing to obtain a third mixture. The reducing agent is added to the third mixture for reduction to obtain Ce-containing solution. 3+ Supported PdAg nanomaterials.

[0006] In another aspect of the present invention, preferably, the cerium salt material is soluble in the first solvent; The cerium salt material includes at least one of cerium nitrate, cerium chloride, cerium sulfate, and cerium acetate; The active carrier material includes activated carbon and graphene; The first solvent includes at least one of water and ethanol; The mass ratio of cerium ions, active carrier material, and first solvent in the cerium salt material is (0.001~0.003):0.1:4.

[0007] In another aspect of the present invention, preferably, the first mixing includes mixing using ultrasound, wherein the ultrasound duration is 1.5 to 2.5 hours and the ultrasound power is 350 to 450 W.

[0008] In another aspect of the present invention, preferably, the temperature of the rotary evaporation process is 70~90°C and the rotation speed is 25~35 rpm.

[0009] In another aspect of the present invention, preferably, The plasma treatment time is 1~2s, and the plasma treatment current is 45~55A; The washing process includes washing with deionized water and ethanol 2 to 4 times; The drying process includes drying in a vacuum environment at 50~70℃ for 10~14 hours.

[0010] In another aspect of the invention, preferably, the coupling agent comprises at least one of 3-aminopropyltriethoxysilane and aminopropyltrimethoxysilane; The second solvent includes deionized water and ultrapure water; The mass ratio of the carrier, coupling agent, and second solvent is 1:4 to 5:300.

[0011] In another aspect of the present invention, preferably, the second mixing of the carrier and the coupling agent in a second solvent to obtain a second mixture comprises: The carrier is mixed in a second solvent using ultrasound for 0.5 to 1.5 hours at a power of 350 to 450 W to obtain a suspension. The coupling agent is added to the suspension and mixed using ultrasound and magnetic stirring. The ultrasound time is 0.5~1.5h, the ultrasound power is 350~450W, the magnetic stirring time is 0.5~1.5h, and the rotation speed is 20~30 rpm.

[0012] In another aspect of the present invention, preferably, both the palladium salt material and the silver salt material are soluble in the second solvent; The palladium salt material includes at least one of palladium chloride, palladium nitrate, and sodium tetrachloropalladate. The silver salt material includes at least one of silver nitrate and silver acetate; The molar ratio of palladium ions in the palladium salt material to silver ions in the silver salt material is 1:0.8~1.2; The third mixing includes mixing using magnetic stirring, with the stirring time being 1.5 to 2.5 hours and the stirring speed being 20 to 30 revolutions per minute.

[0013] In another aspect of the present invention, preferably, the reducing agent comprises at least one of sodium borohydride and boron hydride; The mass ratio of the reducing agent, palladium salt material, and silver salt material is 3~4:0.5~0.7.

[0014] In another aspect of the present invention, preferably, the reduction agent is added to the third mixture for reduction to obtain Ce-containing... 3+ Supported PdAg nanomaterials include: The reducing agent is added to the third mixture and mixed using magnetic stirring for 1.5 to 2.5 hours at a speed of 20 to 30 revolutions per minute. Wash 2-4 times with deionized water using centrifugation. Drying in a vacuum environment at 50~70℃ for 10~14h yields Ce-containing products. 3+ Supported PdAg nanomaterials.

[0015] (III) Beneficial Effects The above-described technical solution of the present invention has the following beneficial technical effects: This invention combines plasma activation with an active carrier material to rapidly prepare amorphous materials rich in Ce. 3+ The carrier avoids the Ce caused by traditional high-temperature calcination. 3+ To Ce 4+ The transformation problem aims to maintain a high Ce content in the material. 3+The amorphous cerium oxide and active support material, due to their loose structure, large specific surface area, and abundant surface defects, provide more binding and anchoring sites for noble metal nanoparticles. Under the synergistic effect of coupling agents, Pd and Ag salts achieve efficient adsorption and uniform distribution on the support surface, forming highly dispersed PdAg bimetallic nanoparticles after reduction, and establishing stable metal-support interface interactions. (Ce-rich) 3+ Cerium oxide can significantly modulate the electronic structure of PdAg, enhance the dehydrogenation ability of metal active sites for formic acid molecules, and form a reaction pathway that is more conducive to H2 generation, thereby enabling the catalyst to exhibit higher catalytic activity and better product selectivity in the formic acid dehydrogenation process. Attached Figure Description

[0016] Figure 1 This is an overall flowchart of one embodiment of the present invention; Figure 2 This is a transmission electron microscope image of the nanomaterial of Example 2 of the present invention; Figure 3 This is a high-resolution transmission electron microscope image of the nanomaterial of Example 2 of the present invention; Figure 4 These are the X-ray photoelectron spectra of the nanomaterials in Examples 1, 2, and 3 of this invention; Figure 5 These are the Raman spectra of the nanomaterials of Example 2 and Comparative Example 1 of the present invention; Figure 6 These are the X-ray diffraction patterns of the nanomaterials of Example 2 and Comparative Example 1 of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0018] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Example A Ce-containing 3+ Preparation method of supported PdAg nanomaterials. Figure 1 An overall flowchart of one embodiment of the present invention is shown, as follows: Figure 1 As shown, it includes: A first mixture is obtained by mixing a cerium salt material and an active carrier material in a first solvent. The cerium salt material is soluble in the first solvent, ensuring that cerium ions can fully contact and adsorb onto the surface of the active carrier material. The cerium salt material includes at least one of cerium nitrate, cerium chloride, cerium sulfate, and cerium acetate, or it can be a mixture of two or more cerium salts. The active carrier material can be an oxide, a carbon material, or a porous material with a surface hydroxyl structure to ensure good adsorption capacity and surface reactivity. The active carrier material includes activated carbon and graphene. The first solvent includes at least one of water and ethanol. Water provides good cerium salt solubility, while ethanol can enhance the wetting and diffusion effect on the surface of the active carrier. The first solvent can be a solvent in which the ratio of the two is adjusted as needed. The mass ratio of cerium ions in the cerium salt material, the active carrier material, and the first solvent is (0.001~0.003):0.1:4. Within this mass ratio range, the concentration of cerium ions is moderate, which can avoid excessive accumulation or agglomeration of cerium species, while ensuring that they can be uniformly adsorbed or deposited on the carrier surface, thereby forming a stable precursor system.

[0022] In this embodiment, the first mixing includes ultrasonic mixing, wherein the ultrasonic treatment time is 1.5 to 2.5 hours and the ultrasonic power is 350 to 450 W. Ultrasonic treatment effectively promotes the rapid dissolution of cerium salt in the solvent and enhances the adsorption efficiency of cerium ions on the surface of the active carrier material. To ensure the adequacy of the mixing process, the ultrasonic treatment time is controlled within the range of 1.5 to 2.5 hours. Too short an ultrasonic treatment time may result in incomplete dissolution or insufficient dispersion of the cerium salt material, thus affecting the uniform deposition of cerium ions on the carrier surface; while too long an ultrasonic treatment time may cause structural damage to the carrier material, reducing its subsequent ability to load noble metals. The ultrasonic power is selected as 350 to 450 W. This power range ensures effective dispersion while avoiding excessive mechanical impact on the carrier material. Too low an ultrasonic power can easily lead to uneven mixing, preventing the cerium salt from fully penetrating into the pores or surface active sites of the carrier; while too high an ultrasonic power may cause particle breakage, pore structure collapse, or damage to surface functional groups, thereby affecting the final material properties. During the ultrasonic mixing process, continuous or intermittent ultrasonic methods can be used, and the process can be carried out at room temperature or under appropriate temperature control conditions.

[0023] The first mixture is subjected to rotary evaporation to obtain precursor powder. The rotary evaporation process is carried out at a temperature of 70-90°C and a rotation speed of 25-35 rpm. This process removes the first solvent and yields the solid precursor powder. The rotary evaporation step accelerates solvent evaporation under reduced pressure while maintaining uniform stirring of the system. This facilitates the uniform deposition of cerium salt materials on the surface of the active carrier material, resulting in a precursor structure with consistent composition. The rotary evaporation temperature is controlled within the range of 70-90°C. This temperature range effectively promotes the rapid evaporation of the first solvent, such as water or ethanol, and avoids adverse effects such as solvent residue due to excessively low temperatures or changes in cerium salt crystal form and damage to the carrier surface structure due to excessively high temperatures. Choosing this temperature range ensures a uniform distribution of cerium salt on the carrier surface while maintaining the stability of the material structure. Setting the rotary evaporator speed to 25–35 rpm not only enhances the expansion of the liquid film and increases the contact area between the solvent and air, but also maintains the overall homogeneity of the system, preventing problems such as carrier sedimentation, accumulation, or localized uneven concentration during evaporation. If the speed is too low, the mixture is prone to localized deposition on the vessel wall; if the speed is too high, it may cause liquid splashing or introduce too many air bubbles, affecting the powder forming quality.

[0024] The precursor powder is subjected to plasma treatment, washing, and drying sequentially to obtain a carrier; the plasma treatment time is 1-2 seconds, and the plasma treatment current is 45-55 A; plasma can rapidly activate and structurally regulate the cerium salt precursor under rapid high-temperature conditions, transforming the cerium species from a crystalline or partially crystalline state to an amorphous structure, while avoiding the Ce loss caused by traditional high-temperature calcination. 3+ To Ce 4+ The process transforms the surface oxygen vacancies, resulting in a high concentration. The plasma treatment time is 1-2 seconds to avoid excessive bombardment that could damage the carrier structure. The selected current range ensures stable plasma discharge, making the activation process uniform and controllable. Furthermore, the short plasma treatment time shortens the overall preparation cycle.

[0025] The washing process includes 2-4 washes with deionized water and ethanol to remove unreacted ion residues and potential byproducts. Deionized water effectively dissolves residual inorganic salts, while ethanol promotes solvent exchange and reduces powder agglomeration, while also accelerating the subsequent drying process. Multiple washes ensure thorough removal of impurities, resulting in a cleaner carrier surface, which is beneficial for subsequent coupling agent adsorption and metal ion complexation.

[0026] The drying process involves drying in a vacuum environment at 50–70°C for 10–14 hours. After washing, the powder is dried to obtain a stable solid carrier. This drying process is carried out in a vacuum environment at 50–70°C for 10–14 hours. Vacuum conditions help remove residual solvents at lower temperatures and avoid Ce under high-temperature conditions. 3+ Re-oxidized to Ce 4+ This process preserves the amorphous structure and oxygen vacancy characteristics of the carrier surface. The selection of drying temperature and time ensures complete dehydration of the powder while preventing structural collapse or particle agglomeration.

[0027] The carrier and coupling agent are mixed a second time in a second solvent to obtain a second mixture. The treated carrier and coupling agent are then added to the second solvent for a second mixing to achieve effective anchoring of the coupling agent on the carrier surface, thereby enhancing the subsequent adsorption capacity and loading uniformity of metal ions. The coupling agent includes at least one of 3-aminopropyltriethoxysilane and aminopropyltrimethoxysilane. The coupling agent modifies the carrier, introducing active functional groups such as amino groups onto the carrier surface. These active functional groups can form complexes with metal ions in palladium and silver salts, achieving uniform dispersion of metal ions on the carrier surface. Subsequent reduction with reducing agents such as sodium borohydride forms highly dispersed PdAg bimetallic nanoparticles, preventing particle aggregation. In this embodiment, the amino functional groups of 3-aminopropyltriethoxysilane and aminopropyltrimethoxysilane have strong coordination properties, effectively anchoring the PdAg bimetallic nanoparticles. 2+ Ag + It has strong complexing ability and can form stable metal-ligand complexes, which can significantly improve the adsorption and fixation effect of metal ions on the carrier surface, resulting in smaller particle size and more uniform dispersion of the PdAg bimetallic nanoparticles formed subsequently.

[0028] The second solvent includes deionized water and ultrapure water; The mass ratio of the carrier, coupling agent, and second solvent is 1:4 to 5:300. The amount of coupling agent ensures the formation of a uniform and dense organic functional layer on the carrier surface; the sufficient volume of the second solvent provides a suitable flow environment for ultrasound and stirring, allowing the modification reaction to be more complete.

[0029] The step of mixing the carrier and coupling agent in a second solvent to obtain a second mixture includes: The carrier is mixed in a second solvent using ultrasound for 0.5 to 1.5 hours at a power of 350 to 450 W to obtain a suspension. This effectively disperses the carrier particles, promotes full exposure of their surface, and forms a uniform suspension, which is beneficial for the subsequent adsorption of coupling agents.

[0030] The coupling agent is added to the suspension and mixed using ultrasound and magnetic stirring. Ultrasounding time is 0.5–1.5 h to promote complete hydrolysis of the coupling agent and its bonding with functional groups on the support surface. The ultrasound power is 350–450 W, and the magnetic stirring time is 0.5–1.5 h at a speed of 20–30 rpm. Continuous stirring improves the homogeneity of the system and prevents local enrichment or aggregation of the coupling agent, thus ensuring a uniform modified layer covering the support surface. This second mixing process introduces a large number of stable amino and other active functional groups onto the support surface, resulting in a second mixture with good metalophilicity and reactivity, providing a reliable foundation for the subsequent complexation, adsorption, and uniform loading of Pd / Ag metal salts.

[0031] Palladium salt material and silver salt material are added to the second mixture for a third mixing to obtain a third mixture; by forming a stable Pd and Ag ion complex layer on the surface of the support, a foundation is laid for the subsequent reduction to generate supported PdAg nanoparticles. Both the palladium salt material and the silver salt material are soluble in the second solvent; the palladium salt material includes at least one of palladium chloride, palladium nitrate, and sodium tetrachloropalladate, which can be used alone or in combination; the silver salt material includes at least one of silver nitrate and silver acetate. The molar ratio of palladium ions in the palladium salt material to silver ions in the silver salt material is 1:0.8~1.2; regarding the metal ion ratio, the molar ratio of palladium ions in the palladium salt material to silver ions in the silver salt material is controlled within the range of 1:0.8~1.2. This molar ratio allows for the adjustment of the composition ratio of Pd and Ag, achieving a synergistic catalytic effect of bimetallic nanoparticles, and avoiding particle agglomeration or reduced activity caused by an excess of a single metal while ensuring catalytic activity and selectivity.

[0032] The third mixing process includes mixing using magnetic stirring for 1.5 to 2.5 hours at a speed of 20 to 30 revolutions per minute. This allows Pd to... 2+ With Ag + Ions are fully adsorbed on the active sites modified by the coupling agent on the support surface, forming a uniform metal precursor layer.

[0033] The reducing agent is added to the third mixture for reduction to obtain Ce-containing solution. 3+ Supported PdAg nanomaterials. The aim is to utilize PdAg nanomaterials adsorbed on the surface of a support or complexed on a coupling agent. 2+ With Ag + Ions are reduced to metallic nanoparticles while preserving Ce in the support. 3+ The enriched state of the material allows for the production of bimetallic nanomaterials with uniform structure, controllable particle size, and excellent catalytic performance.

[0034] The reducing agent includes at least one of sodium borohydride and boron hydride; the mass ratio of the reducing agent to the sum of the palladium salt material and the silver salt material is 3~4:0.5~0.7.

[0035] The reducing agent is added to the third mixture for reduction to obtain Ce-containing solution. 3+ Supported PdAg nanomaterials include: The reducing agent is added to the third mixture, and the mixture is stirred magnetically for 0.5–1.5 hours at a speed of 20–30 rpm. During stirring, the metal ions are gradually reduced to PdAg nanoparticles, forming highly dispersed bimetallic particles on the carrier surface. Appropriate stirring time and speed help prevent particle aggregation or sedimentation during the reaction and ensure the homogeneity of the entire system.

[0036] Wash the product 2-4 times with deionized water using centrifugation. After reduction, wash the product to remove residual reducing agent and byproducts. Washing can be done with deionized water, using centrifugation for 2-4 exchanges to ensure thorough washing and removal of soluble salts and unreacted substances, thereby obtaining a clean PdAg nanoparticle-supported system.

[0037] Drying in a vacuum environment at 50~70℃ for 10~14h yields Ce-containing products. 3+ Supported PdAg nanomaterials. Vacuum drying can remove residual moisture or solvent at low temperatures, avoiding the damage to Ce caused by high temperatures. 3+ Oxidized to Ce 4+ Alternatively, metal particles can be sintered to maintain the stability of the support structure and the high dispersibility of the PdAg nanoparticles. After drying, the final Ce-containing nanoparticles are obtained. 3+ Supported PdAg nanomaterials with Ce-rich surfaces 3+ It is rich in oxygen vacancies and has uniformly dispersed metal particles, making it suitable for highly efficient catalytic reactions, especially for catalytic applications such as formic acid dehydrogenation. It is also rich in Ce. 3+ The carrier has abundant oxygen vacancies, which can significantly modulate the electronic structure of PdAg bimetals, enhance the adsorption and activation ability of metal active sites for formic acid molecules, optimize the dehydrogenation reaction pathway, and improve catalytic efficiency and selectivity.

[0038] This invention combines plasma activation with an active carrier material to rapidly prepare amorphous materials rich in Ce. 3+ The carrier avoids the Ce caused by traditional high-temperature calcination. 3+ To Ce 4+ The transformation problem aims to maintain a high Ce content in the material. 3+The amorphous cerium oxide and active support material, due to their loose structure, large specific surface area, and abundant surface defects, provide more binding and anchoring sites for noble metal nanoparticles. Under the synergistic effect of coupling agents, Pd and Ag salts achieve efficient adsorption and uniform distribution on the support surface, forming highly dispersed PdAg bimetallic nanoparticles after reduction, and establishing stable metal-support interface interactions. (Ce-rich) 3+ Cerium oxide can significantly modulate the electronic structure of PdAg, enhance the dehydrogenation ability of metal active sites for formic acid molecules, and form a reaction pathway that is more conducive to H2 generation, thereby making the catalyst exhibit higher catalytic activity and better product selectivity in the formic acid dehydrogenation process.

[0039] Example 1 17 mg of cerium nitrate and 500 mg of activated carbon were dispersed in 20 mL of deionized water and sonicated for 2 h at an ultrasonic power of 400 W to obtain the first mixture.

[0040] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 80°C and the rotation speed was 30 rpm to obtain the precursor powder.

[0041] 20 mg of precursor powder was weighed and placed in a crucible, which was placed directly below the plasma jet and 2 cm away from the plasma outlet for plasma treatment. The operating current was controlled by the power supply, and the reaction time was precisely controlled by the timer. The plasma treatment time was controlled to be 1 s and the plasma operating current was 50 A. The plasma-treated powder was washed three times with deionized water and ethanol to remove unreacted cerium nitrate. It was then vacuum dried at 60 °C for 12 h to obtain CeO2-C support.

[0042] Weigh 100 mg of CeO2-C carrier and add it to 30 mL of deionized water. Sonicate for 1 h at a power of 400 W to obtain a suspension. Add 0.5 mL of 3-aminopropyltriethoxysilane to the suspension and sonicate for 1 h at a power of 400 W. Stir magnetically for 1 h at a speed of 30 rpm to obtain a second mixture.

[0043] 0.01 mmol of sodium tetrachloropalladium and 0.01 mmol of silver nitrate were weighed and added to a mixed solution. The mixture was magnetically stirred for 2 hours at 30 rpm. Then, 30 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 2 hours at 30 rpm. After centrifugation, the mixture was washed three times with deionized water and vacuum dried at 60 °C for 12 hours to obtain PdAg-NH2 / CeO2-C nanomaterials.

[0044] Example 2 34 mg of cerium nitrate and 500 mg of activated carbon were dispersed in 20 mL of deionized water and ultrasonically treated for 2 h at an ultrasonic power of 400 W to obtain the first mixture.

[0045] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 80°C and the rotation speed was 30 rpm to obtain the precursor powder.

[0046] 20 mg of precursor powder was weighed and placed in a crucible, which was positioned directly below the plasma jet and 2 cm away from the plasma outlet for plasma treatment. The operating current was controlled by a power supply, and the reaction time was precisely controlled by a timer. The plasma treatment time was controlled to be 1 s, and the plasma operating current was 50 A. The plasma-treated powder was washed three times with deionized water and ethanol to remove unreacted cerium nitrate, and then vacuum dried at 60 °C for 12 h to obtain the CeO2-C support.

[0047] Weigh 100 mg of CeO2-C carrier and add it to 30 mL of deionized water. Sonicate for 1 h at a power of 400 W to obtain a suspension. Add 0.5 mL of 3-aminopropyltriethoxysilane to the suspension and sonicate for 1 h at a power of 400 W. Stir magnetically for 1 h at a speed of 30 rpm to obtain a second mixture.

[0048] 0.01 mmol of sodium tetrachloropalladium and 0.01 mmol of silver nitrate were weighed and added to a mixed solution. The mixture was magnetically stirred for 2 hours at 30 rpm. Then, 30 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 2 hours at 30 rpm. After centrifugation, the mixture was washed three times with deionized water and vacuum dried at 60 °C for 12 hours to obtain PdAg-NH2 / CeO2-C nanomaterials. Figure 2 A transmission electron microscope image of the nanomaterial of Example 2 of the present invention is shown; Figure 3 A high-resolution transmission electron microscope image of the nanomaterial of Example 2 of the present invention is shown; as follows: Figure 2 and Figure 3 As shown, PdAg and CeO2 nanoparticles are uniformly dispersed on a carbon substrate. The lattice spacing of 0.231 nm belongs to the (111) plane of PdAg, and CeO2 is an amorphous amorphous structure.

[0049] Example 3 51 mg of cerium nitrate and 500 mg of activated carbon were dispersed in 20 mL of deionized water and ultrasonically treated for 2 h at an ultrasonic power of 400 W to obtain the first mixture.

[0050] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 80°C and the rotation speed was 30 rpm to obtain the precursor powder.

[0051] 20 mg of precursor powder was weighed and placed in a crucible, which was positioned directly below the plasma jet and 2 cm away from the plasma outlet for plasma treatment. The operating current was controlled by a power supply, and the reaction time was precisely controlled by a timer. The plasma treatment time was controlled to be 1 s, and the plasma operating current was 50 A. The plasma-treated powder was washed three times with deionized water and ethanol to remove unreacted cerium nitrate, and then vacuum dried at 60 °C for 12 h to obtain the CeO2-C support.

[0052] Weigh 100 mg of CeO2-C carrier and add it to 30 mL of deionized water. Sonicate for 1 h at a power of 400 W to obtain a suspension. Add 0.5 mL of 3-aminopropyltriethoxysilane to the suspension and sonicate for 1 h at a power of 400 W. Stir magnetically for 1 h at a speed of 30 rpm to obtain a second mixture.

[0053] 0.01 mmol of sodium tetrachloropalladium and 0.01 mmol of silver nitrate were weighed and added to a mixed solution. The mixture was magnetically stirred for 2 hours at 30 rpm. Then, 30 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 2 hours at 30 rpm. After centrifugation, the mixture was washed three times with deionized water and vacuum dried at 60 °C for 12 hours to obtain PdAg-NH2 / CeO2-C nanomaterials. Figure 4 The X-ray photoelectron spectra of the nanomaterials of Examples 1, 2, and 3 of the present invention are shown, as follows: Figure 4 As shown, with the increase of Ce content, the Ce in the sample... 3+ The content has increased.

[0054] Example 4 30 mg of cerium chloride and 500 mg of activated carbon were dispersed in 20 mL of deionized water and ultrasonically treated for 1.5 h at an ultrasonic power of 350 W to obtain the first mixture.

[0055] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 70°C and the rotation speed was 25 rpm to obtain the precursor powder.

[0056] 20 mg of precursor powder was weighed and placed in a crucible, which was placed directly below the plasma jet and 2 cm away from the plasma outlet for plasma treatment. The operating current was controlled by the power supply, and the reaction time was precisely controlled by the timer. The plasma treatment time was controlled to be 2 s and the plasma operating current was 45 A. The plasma-treated powder was washed twice with deionized water and ethanol to remove unreacted cerium nitrate. It was then vacuum dried at 50 °C for 14 h to obtain CeO2-C support.

[0057] Weigh 100 mg of CeO2-C carrier and add it to 30 mL of deionized water. Sonicate the mixture for 0.5 h at a power of 350 W to obtain a suspension. Add 400 mg of 3-aminopropyltriethoxysilane to the suspension and sonicate it for 0.5 h at a power of 350 W. Stir the mixture magnetically for 0.5 h at a speed of 20 rpm to obtain a second mixture.

[0058] 0.01 mmol of palladium nitrate and 0.01 mmol of silver acetate were weighed and added to a mixed solution. The mixture was magnetically stirred for 1.5 h at 20 rpm. 24.8 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 1.5 h at 20 rpm. After centrifugation, the mixture was washed twice with deionized water and vacuum dried at 50 °C for 14 h to obtain PdAg-NH2 / CeO2-C nanomaterials.

[0059] Example 5 30 mg of cerium sulfate and 500 mg of activated carbon were dispersed in 20 mL of deionized water and ultrasonically treated for 2.5 h at an ultrasonic power of 450 W to obtain the first mixture.

[0060] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 90°C and the rotation speed was 35 rpm to obtain the precursor powder.

[0061] 20 mg of precursor powder was weighed and placed in a crucible, which was placed directly below the plasma jet and 2 cm away from the plasma outlet for plasma treatment. The operating current was controlled by the power supply, and the reaction time was precisely controlled by the timer. The plasma treatment time was controlled to be 1 s and the plasma operating current was 55 A. The plasma-treated powder was washed four times with deionized water and ethanol to remove unreacted cerium nitrate. It was then vacuum dried at 70 °C for 10 h to obtain CeO2-C support.

[0062] Weigh 100 mg of CeO2-C carrier and add it to 30 mL of deionized water. Sonicate for 1.5 h at a power of 450 W to obtain a suspension. Add 500 mg of 3-aminopropyltriethoxysilane to the suspension and sonicate for 1.5 h at a power of 450 W. Stir magnetically for 1.5 h at a speed of 25 rpm to obtain a second mixture.

[0063] 0.01 mmol of palladium nitrate and 0.01 mmol of silver acetate were weighed and added to a mixed solution. The mixture was magnetically stirred for 2.5 h at 25 rpm. 34.67 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 2.5 h at 25 rpm. After centrifugation, the mixture was washed four times with deionized water and vacuum dried at 70 °C for 10 h to obtain PdAg-NH2 / CeO2-C nanomaterials.

[0064] Comparative Example 1 500 mg of activated carbon was dispersed in 20 mL of deionized water and ultrasonically treated for 2 h at an ultrasonic power of 400 W to obtain the first mixture.

[0065] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 80°C and the rotation speed was 30 rpm to obtain the precursor powder.

[0066] 20 mg of precursor powder was weighed and placed in a crucible, which was placed directly below the plasma jet and 2 cm away from the plasma outlet for plasma treatment. The operating current was controlled by the power supply, and the reaction time was precisely controlled by the timer. The plasma treatment time was controlled to be 1 s and the plasma operating current was 50 A. The plasma-treated powder was washed three times with deionized water and ethanol to remove impurities and then dried under vacuum at 60 °C for 12 h to obtain C support.

[0067] Weigh 100 mg of C carrier and add it to 30 mL of deionized water. Sonicate for 1 h at a power of 400 W to obtain a suspension. Add 0.5 mL of 3-aminopropyltriethoxysilane to the suspension, sonicate for 1 h at a power of 400 W, and magnetically stir for 1 h at a speed of 30 rpm to obtain a second mixture.

[0068] 0.01 mmol of sodium tetrachloropalladium and 0.01 mmol of silver nitrate were weighed and added to a mixed solution. The mixture was magnetically stirred for 2 hours at 30 rpm. Then, 30 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 2 hours at 30 rpm. After centrifugation, the mixture was washed three times with deionized water and vacuum dried at 60 °C for 12 hours to obtain PdAg-NH2 / C nanomaterials. Figure 5 Raman spectra of the nanomaterials of Example 2 and Comparative Example 1 of the present invention are shown; Figure 6 The X-ray diffraction patterns of the nanomaterials of Example 2 and Comparative Example 1 of the present invention are shown; as follows: Figure 5 and Figure 6 As shown, the F of CeO2 appeared in the Raman spectrum. 2g and O v The absence of obvious metal peaks in the X-ray diffraction pattern is due to the low loading and high dispersion of the metal.

[0069] Comparative Example 2 34 mg of cerium nitrate and 500 mg of activated carbon were dispersed in 20 mL of deionized water and ultrasonically treated for 2 h at an ultrasonic power of 400 W to obtain the first mixture.

[0070] The first mixture was placed in a water bath for rotary evaporation to remove the water solvent. The water bath temperature was set to 80°C and the rotation speed was 30 rpm to obtain the precursor powder.

[0071] The precursor powder was placed in a tube furnace and treated under the following conditions to obtain the CeO2-C support: the temperature was increased from 25°C to 400°C at a heating rate of 5°C / min, held for 2 hours, and then cooled to room temperature with the furnace.

[0072] Weigh 100 mg of CeO2-C carrier and add it to 30 mL of deionized water. Sonicate for 1 h at a power of 400 W to obtain a suspension. Add 0.5 mL of 3-aminopropyltriethoxysilane to the suspension and sonicate for 1 h at a power of 400 W. Stir magnetically for 1 h at a speed of 30 rpm to obtain a second mixture.

[0073] 0.01 mmol of sodium tetrachloropalladium and 0.01 mmol of silver nitrate were weighed and added to a mixed solution. The mixture was magnetically stirred for 2 hours at 30 rpm. Then, 30 mg of sodium borohydride was added, and the mixture was magnetically stirred for another 2 hours at 30 rpm. After centrifugation, the mixture was washed three times with deionized water and vacuum dried at 60 °C for 12 hours to obtain PdAg-NH2 / CeO2-C nanomaterials.

[0074] Table 1 shows the experimental results of Examples 1-5 and Comparative Examples 1-2. As shown in Table 1, the catalytic activity was optimal when the Ce content was 1.4 wt% after plasma treatment.

[0075] Table 1. Experimental results of Examples 1-5 and Comparative Examples 1-2 As shown in Table 1, the turnover frequency of Examples 1-5 is significantly higher than that of Comparative Example 1 and Comparative Example 2. Among them, the turnover frequency of Example 2 is the highest.

[0076] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0077] The present invention has been described above with reference to embodiments thereof. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

[0078] Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and modifications can be made to the embodiments of the present invention without departing from the spirit and scope of the invention.

[0079] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A Ce-containing 3+ The method for preparing supported PdAg nanomaterials is characterized by, include: The cerium salt material and the active carrier material are first mixed in a first solvent to obtain a first mixture; The first mixture was subjected to rotary evaporation to obtain precursor powder; The precursor powder was subjected to plasma treatment, washing treatment and drying treatment in sequence to obtain a carrier; The carrier and coupling agent are mixed a second time in a second solvent to obtain a second mixture; Palladium salt material and silver salt material are added to the second mixture for a third mixing to obtain a third mixture. The reducing agent is added to the third mixture for reduction to obtain Ce-containing solution. 3+ Supported PdAg nanomaterials.

2. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, The cerium salt material is soluble in the first solvent; The cerium salt material includes at least one of cerium nitrate, cerium chloride, cerium sulfate, and cerium acetate; The active carrier material includes activated carbon and graphene; The first solvent includes at least one of water and ethanol; The mass ratio of cerium ions, active carrier material, and first solvent in the cerium salt material is (0.001~0.003):0.1:

4.

3. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, The first mixing includes mixing using ultrasound, wherein the ultrasound duration is 1.5 to 2.5 hours and the ultrasound power is 350 to 450 W.

4. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, The rotary evaporation process is carried out at a temperature of 70-90°C and a rotation speed of 25-35 rpm.

5. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, The plasma treatment time is 1~2s, and the plasma treatment current is 45~55A; The washing process includes washing with deionized water and ethanol 2 to 4 times; The drying process includes drying in a vacuum environment at 50~70℃ for 10~14 hours.

6. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, The coupling agent includes at least one of 3-aminopropyltriethoxysilane and aminopropyltrimethoxysilane; The second solvent includes deionized water and ultrapure water; The mass ratio of the carrier, coupling agent, and second solvent is 1:4 to 5:

300.

7. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, The step of mixing the carrier and coupling agent in a second solvent to obtain a second mixture includes: The carrier is mixed in a second solvent using ultrasound for 0.5 to 1.5 hours at a power of 350 to 450 W to obtain a suspension. The coupling agent is added to the suspension and mixed using ultrasound and magnetic stirring. The ultrasound time is 0.5~1.5h, the ultrasound power is 350~450W, the magnetic stirring time is 0.5~1.5h, and the rotation speed is 20~30 rpm.

8. The Ce-containing [product / service] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by, Both the palladium salt material and the silver salt material are soluble in the second solvent; The palladium salt material includes at least one of palladium chloride, palladium nitrate, and sodium tetrachloropalladate. The silver salt material includes at least one of silver nitrate and silver acetate; The molar ratio of palladium ions in the palladium salt material to silver ions in the silver salt material is 1:0.8~1.2; The third mixing includes mixing using magnetic stirring, with the stirring time being 1.5 to 2.5 hours and the stirring speed being 20 to 30 revolutions per minute.

9. The Ce-containing [product / service] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by: The reducing agent includes at least one of sodium borohydride and boron hydride; The mass ratio of the reducing agent, palladium salt material, and silver salt material is 3~4:0.5~0.

7.

10. The Ce-containing [material] according to claim 1 3+ The method for preparing supported PdAg nanomaterials is characterized by: The reducing agent is added to the third mixture for reduction to obtain Ce-containing solution. 3+ Supported PdAg nanomaterials include: The reducing agent is added to the third mixture and mixed using magnetic stirring for 1.5 to 2.5 hours at a speed of 20 to 30 revolutions per minute. Wash 2-4 times with deionized water and centrifugation. Drying in a vacuum environment at 50-70℃ for 10-14 hours yields Ce-containing products. 3+ Supported PdAg nanomaterials.

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