A supported metal type dehydrogenation catalyst based on a carbon material carrier, a preparation method and application in catalytic dehydrogenation of organic liquid hydrogen storage materials

Abstract

The application provides a carbon material carrier-based supported metal type dehydrogenation catalyst, a preparation method and application in catalytic dehydrogenation of organic liquid hydrogen storage materials, and belongs to the technical field of catalysts. The catalyst comprises 88.5-98.5% of a carrier, 0.5-2.5% of noble metal and 1-9% of an additive. The catalyst can be applied to the reaction of organic liquid hydrogen storage materials, has a relatively high reaction rate, has no other by-products, can be used for multiple times, and has good dehydrogenation stability. The application reduces the usage amount of active components of noble metal in the catalyst and reduces the cost of the catalyst. The cold plasma technology is used to effectively anchor a large amount of active components of noble metal at the interface of the additive-carrier, to generate a large amount of micro-positive noble metal particles, and the strong electronic complementarity between the noble metal and the additive forms a special electronic environment, and the density and flowability of the electrons are improved.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a supported metal dehydrogenation catalyst based on a carbon material support, its preparation method, and its application in the catalytic dehydrogenation of organic liquid hydrogen storage materials. Background Technology

[0002] Hydrogen energy, as a highly efficient, green, and environmentally friendly renewable secondary energy source, has become one of the most promising new energy carriers. Hydrogen storage technology is a key link in realizing the large-scale application of hydrogen energy. Compared with traditional hydrogen storage methods, liquid organic hydrogen carriers (LOHCs) technology achieves reversible storage and release of hydrogen through organic compounds, which not only reduces dependence on special storage conditions but also lowers related energy consumption and safety risks. However, LOHCs technology also faces some challenges. The reaction rate of the addition and dehydrogenation process is often low, and the rate of the addition and dehydrogenation reaction directly affects the efficiency of hydrogen energy application. To meet practical applications, organic liquid hydrogen storage technology often requires specific catalysts.

[0003] In the prior art, CN109701588A discloses a dehydrogenation catalyst and its preparation method. A nitrogen-containing support is prepared using nitrides, and an active component is introduced by impregnation or precipitation. The active component is then reduced at low temperature to complete the preparation of the dehydrogenation catalyst. It exhibits good dehydrogenation performance when used in the dehydrogenation reaction of organic liquid hydrogen storage materials. However, the support preparation is cumbersome and expensive. CN114436208A discloses a catalytic hydrogen supply system based on organic liquids and its hydrogen supply method. This catalytic hydrogen supply system involves an organic liquid hydrogen supply material and a hydrogen supply reaction catalyst. The organic liquid hydrogen supply material is composed of fully hydrogenated benzyltoluene and decahydronaphthalene organic liquid hydrogen supports. The hydrogen supply reaction catalyst is a supported metal catalyst, containing a catalyst support and a catalyst active component. However, the mass percentage of the active metal component in the catalyst is 5.0%–30.0%, and the total mass percentage of the two precious metals, palladium and platinum, is 0.3%–2.0%, resulting in high preparation costs. While the aforementioned technologies have achieved certain results in the catalytic dehydrogenation of organic liquid hydrogen storage materials, the cumbersome preparation of their supports or the large amount of active components required reduces cost-effectiveness and limits large-scale industrial applications. Therefore, designing dehydrogenation catalysts with simple support preparation, low noble metal loading, low cost, and high catalytic activity is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a carbon-based supported metal dehydrogenation catalyst that is simple to prepare, can reduce the loading of precious metals, and improve the utilization efficiency of precious metals in the catalyst.

[0005] To achieve the above objectives, the present invention provides a supported metal dehydrogenation catalyst based on a carbon material support, the catalyst comprising the following components by mass percentage:

[0006] Carrier 88.5%–98.5%, precious metals 0.5%–2.5%, additives 1%–9%;

[0007] The carrier is an activated carbon material; the carbon material is C. 60 At least one of CNTs and CDs;

[0008] The precious metal is at least one of Pd, Pt, Ru, and Rh;

[0009] The auxiliary agent is at least one of elemental or oxide forms of Zn, Fe, Ti, and Ce.

[0010] The precious metal has a 75% to 90% surface charge and is effectively anchored at the additive-carrier interface.

[0011] Preferably, the catalyst has a specific surface area of ​​150–250 m². 2 / g, pore volume 0.60~1.00cm³ 3 / g, with a pore size of 10-15nm.

[0012] Preferably, the method for preparing the carrier is as follows:

[0013] (1) Mix the alkali and carbon material in a dispersant, stir thoroughly and evaporate to dryness, then calcine in an inert gas at 800°C for 1-2 hours to obtain alkali-treated carbon material;

[0014] (2) Cool the alkali-treated carbon material, dissolve it in the same dispersant, and add acid dropwise to obtain acid-treated carbon material;

[0015] (3) The acid-treated carbon material is washed, dried and ground to obtain a carrier.

[0016] More preferably, the alkali is any one of potassium hydroxide, sodium hydroxide, and ammonia water; the dispersant is any one of water, ethanol, and acetone; the inert gas is any one of nitrogen and argon; and the acid is any one of hydrochloric acid, sulfuric acid, and nitric acid.

[0017] The mass ratio of alkali, carbon material, and dispersant in step (1) is 1-5:1:20;

[0018] The mass ratio of the alkali-treated carbon material, dispersant, and acid in step (2) is 1:20:8-10.

[0019] Another object of the present invention is to provide a method for preparing a supported metal dehydrogenation catalyst based on a carbon material support, comprising the following steps:

[0020] S1. The additive precursor and the carrier are mixed in a dispersant, ultrasonicated, stirred, evaporated to dryness, calcined in an inert gas, and cooled to room temperature to obtain the additive-carrier.

[0021] S2. The additive-carrier and the noble metal precursor are mixed in the dispersant, stirred, evaporated, and dried in an oven to obtain the catalyst precursor;

[0022] S3. Place the catalyst precursor into a cold plasma reactor, introduce reaction gas to fully react, and obtain the supported metal dehydrogenation catalyst based on carbon material support.

[0023] Preferably, the precursor of the auxiliary agent in step S1 is an organic or inorganic salt of the auxiliary agent; the dispersant is any one of water, ethanol, and acetone; and the inert gas is any one of nitrogen and argon.

[0024] The ratio of the auxiliary agent precursor, carrier and dispersant is 20-25: 170-180: 50000;

[0025] The roasting temperature is 450–500°C.

[0026] Preferably, the noble metal precursor in step S2 is an organic or inorganic salt of a noble metal; the dispersant is any one of water, ethanol, and acetone.

[0027] The ratio of the additive-carrier, the noble metal precursor and the dispersant is 95-100:1:1950-2000;

[0028] Preferably, the reaction gas in step S3 is any one of O2, H2, and Ar, and the output voltage of the cold plasma is 80-120V.

[0029] The third objective of this invention is to provide an application of the above-mentioned carbon-supported metal dehydrogenation catalyst in the catalytic dehydrogenation reaction of organic liquid hydrogen storage materials;

[0030] The organic liquid hydrogen storage material is a mixture of any one or more of the following: perhydronitropropylcarbazole, perhydronitroethylcarbazole, perhydrodibenzyltoluene, perhydro1-methylindole, and perhydro1,2-dimethylindole.

[0031] Preferably, the temperature of the catalytic dehydrogenation reaction is 100℃~400℃, the mass ratio of the catalyst to the organic liquid hydrogen storage material is 1:5~5:1, and the reaction time is 0~400min.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The carbon-supported metal-based dehydrogenation catalyst provided by this invention can be applied to reactions involving organic liquid hydrogen storage materials. It exhibits a fast reaction rate, produces no other byproducts, can be reused multiple times, and demonstrates good dehydrogenation stability. The support preparation of this invention is simple, and it reduces the amount of noble metal used as the active component, significantly lowering catalyst costs. This invention utilizes cold plasma technology to effectively anchor a large amount of the active noble metal at the promoter-support interface, generating numerous micro-positively charged noble metal particles. The strong electronic complementarity between the noble metal and the promoter creates a unique electronic environment, increasing electron density and mobility. These micro-positively charged noble metal particles enhance the dehydrogenation reaction rate, and the promoter can quickly replenish the energy consumed during the reaction, forming a unique synergistic mechanism. This enhances the catalyst's activity and stability, making the dehydrogenation reaction more efficient and sustainable. Attached Figure Description

[0034] Figure 1 The physical adsorption-desorption curves of the carbon-supported metal dehydrogenation catalyst prepared in Example 2 are shown.

[0035] Figure 2 The pore size distribution diagram is shown for the carbon-supported metal dehydrogenation catalyst prepared in Example 2.

[0036] Figure 3 TEM image of the carbon-supported metal dehydrogenation catalyst prepared in Example 2;

[0037] Figure 4 The graph shows the relationship between the amount of hydrogen released by the carbon-supported metal dehydrogenation catalyst prepared in Example 2 and the amount of hydrogen released by the dehydrogenation of perhydropropylcarbazole.

[0038] Figure 5 The graph shows the dehydrogenation cycle stability of the carbon-supported metal dehydrogenation catalyst prepared in Example 2.

[0039] Figure 6 Comparison of ammonia temperature-programmed desorption (NH3-TPD) tests on catalysts of Examples 2, 5, 6, 7, and 8 (with different CeO2 loadings);

[0040] Figure 7 Comparison chart of hydrogen temperature programmed desorption (H2-TPD) tests on catalysts of Examples 2, 9, 10 (cold plasma treatment with different gas sources) and Example 11 (without cold plasma treatment);

[0041] Figure 8The graph shows the relationship between the dehydrogenation and hydrogen release of the catalysts in Examples 2, 9, 10 (cold plasma treatment with different gas sources) and Example 11 (without cold plasma treatment) on the total hydrogenated nitrogen propylcarbazole. Detailed Implementation

[0042] This invention provides a supported metal dehydrogenation catalyst based on a carbon material support, the catalyst comprising the following components by mass percentage:

[0043] Carrier 88.5%–98.5%, precious metals 0.5%–2.5%, additives 1%–9%;

[0044] The carrier is an activated carbon material; the carbon material is at least one of C60, CNT, and CDs.

[0045] The precious metal is at least one of Pd, Pt, Ru, and Rh;

[0046] The auxiliary agent is at least one of the elements or oxides of Zn, Fe, Ti, and Ce;

[0047] The noble metal has 75% to 90% of its surface with a micro-positive charge and is effectively anchored at the additive-carrier interface; specifically, the micro-positive charge is a +2 valence micro-positive charge.

[0048] In a specific embodiment of the present invention, the catalyst has a specific surface area of ​​150–250 m². 2 / g, pore volume 0.60~1.00cm³ 3 / g, with a pore size of 10-15nm.

[0049] In a specific embodiment of the present invention, the method for preparing the carrier is as follows:

[0050] (1) Mix the alkali and carbon material in a dispersant, stir thoroughly and evaporate to dryness, then calcine in an inert gas at 800°C for 1-2 hours to obtain alkali-treated carbon material;

[0051] (2) Cool the alkali-treated carbon material, dissolve it in the same dispersant, and add acid dropwise to obtain acid-treated carbon material;

[0052] (3) The acid-treated carbon material is repeatedly rinsed with deionized water until neutral, dried, and ground to obtain a pore volume of 1–1.5 cm. 3 / g, carbon material carrier with a pore size of 10-20nm;

[0053] In a specific embodiment of the present invention, the alkali is any one of potassium hydroxide, sodium hydroxide, and ammonia water; the dispersant is any one of water, ethanol, and acetone; the inert gas is any one of nitrogen and argon; and the acid is any one of hydrochloric acid, sulfuric acid, and nitric acid.

[0054] The mass ratio of alkali, carbon material, and dispersant in step (1) is 4:1:20;

[0055] The mass ratio of the alkali-treated carbon material, dispersant, and acid in step (2) is 1:20:8.

[0056] This invention also provides a method for preparing a supported metal dehydrogenation catalyst based on a carbon material support, comprising the following steps:

[0057] S1. Mix the auxiliary agent precursor and the carrier in a dispersant, sonicate for 10-15 min, stir magnetically for 3-3.5 h, evaporate to dryness at 75-85 °C, calcine at 450-500 °C for 2-2.5 h in an inert gas at a rate of 10-13 °C / min, and cool to room temperature to obtain the auxiliary agent-carrier.

[0058] The precursor of the auxiliary agent is an organic or inorganic salt of the auxiliary agent; the dispersant is any one of water, ethanol, and acetone; the inert gas is any one of nitrogen and argon.

[0059] The ratio of the auxiliary agent precursor, carrier and dispersant is 25:173:50000;

[0060] S2. Mix the additive-carrier and the noble metal precursor in the dispersant, stir for 10-12 hours, evaporate to dryness at 80℃, and then directly transfer to an oven to dry at 50-100℃ for 12-24 hours to obtain the catalyst precursor.

[0061] The noble metal precursor is an organic or inorganic salt of a noble metal; the dispersant is any one of water, ethanol, and acetone.

[0062] The ratio of the auxiliary agent-carrier, the noble metal precursor and the dispersant is 99:1:1980;

[0063] S3. Place the catalyst precursor into the DBD cold plasma reactor, introduce the reaction gas at a flow rate of 10 mL / min for 15 min, then turn on the reactor and set the output voltage to 80-120V, react for 2-3 min, cool, and repeat the process 3-4 times to obtain the supported metal dehydrogenation catalyst based on carbon material support; the reaction gas is any one of O2, H2, and Ar.

[0064] In a specific embodiment of the present invention, the DBD cold plasma reaction device used includes a cold plasma generator with a CTP-2000K experimental power supply, an inductively coupled cold plasma emission spectrometer with an OPTIMA 5300DV, and a gas cylinder.

[0065] In a specific embodiment of the present invention, for the auxiliary agent precursor, when the auxiliary agent is Zn, the precursor is one of zinc chloride, zinc sulfate, and zinc nitrate; when the auxiliary agent is Fe, the precursor is one of ferric chloride, ferric sulfate, and ferric nitrate; when the auxiliary agent is Ti, the precursor is one of tetrabutyl titanate, titanium sulfate, and titanium nitrate; when the auxiliary agent is Ce, the precursor is one of cerium chloride, cerium sulfate, and cerium nitrate hexahydrate; and the dispersant is one of water, ethanol, and acetone.

[0066] In a specific embodiment of the present invention, for the noble metal precursor, when the noble metal is Pd, the precursor is one of palladium acetate, sodium chloropalladium, or sodium bromopalladium; when the noble metal is Pt, the precursor is one of sodium chloroplatinate, dichlorodiammineplatinum, or potassium pentachloroammineplatinum; when the noble metal is Ru, the precursor is one of ruthenium chloride, ruthenium acetate, or ruthenium nitrate; when the noble metal is Rh, the precursor is one of rhodium chloride, rhodium sulfate, or rhodium nitrate; and the dispersant is one of water, hydrochloric acid, or ammonia.

[0067] The carbon-supported metal dehydrogenation catalyst prepared in this invention is used in the catalytic dehydrogenation reaction of organic liquid hydrogen storage material. The specific method is as follows: the catalyst and organic liquid hydrogen storage material are mixed at a mass ratio of 1:5 to 5:1 and reacted at a temperature of 100℃ to 400℃ for 0 to 400 min.

[0068] The organic liquid hydrogen storage material is a mixture of any one or more of the following: perhydronitropropylcarbazole, perhydronitroethylcarbazole, perhydrodibenzyltoluene, perhydro1-methylindole, and perhydro1,2-dimethylindole.

[0069] The present invention will be further described below with reference to the embodiments.

[0070] Example 1

[0071] The preparation method of carbon material carriers includes the following steps:

[0072] (1) Mix 4g KOH and 1g CNT in 20mL of deionized water, stir thoroughly, evaporate to dryness, transfer to a tube furnace, and calcine at 800℃ for 1h under Ar atmosphere to obtain alkali-treated carbon material.

[0073] (2) The alkali-treated carbon material was redissolved in 20 mL of deionized water and 1 M hydrochloric acid was added dropwise to obtain the acid-treated carbon material;

[0074] (3) Finally, rinse repeatedly with deionized water until neutral, dry and grind to obtain an average pore volume of 1.22 cm³. 3 / g, CNT carrier with an average pore size of 16.3nm.

[0075] The carriers used in the following examples are all from Example 1.

[0076] Example 2

[0077] A method for preparing a supported metal dehydrogenation catalyst based on a carbon material support, comprising the following steps:

[0078] S1. Take 0.125g Ce(NO3)3·6H2O and 0.865g CNT support and add them to a beaker. Add 250mL of deionized water. After sonicating the mixture for 10min, stir magnetically for 3h. After evaporating to dryness at 80℃, transfer it to a tube furnace and heat it to 450℃ at a rate of 10℃ / min under N2 atmosphere. Hold for 2h and cool to room temperature to obtain CeO2-CNT.

[0079] S2. Take 0.495g CeO2-CNT, add 10mL of 1M ammonia water and 1mL of 5mg / mL Na2PdCl4 into a beaker, stir continuously for 12h, evaporate to dryness at 80℃, transfer to an oven and dry at 70℃ for 24h. After complete drying, the catalyst precursor is obtained.

[0080] S3. Spread the catalyst precursor evenly in the DBD cold plasma reactor, cover with a sealing cap, and introduce Ar at a flow rate of 10 mL / min for 15 min. Turn on the reactor and set the output voltage to 100V. React for 2 min. After turning off the reactor, stir the sample evenly and spread it evenly in the reactor again. Cool for 3 min and react again. Repeat the process three times to obtain the supported metal dehydrogenation based on carbon material support, denoted as Pd / 5%CeO2-C-Ar.

[0081] The theoretical loading of the catalyst, the noble metal Pd, is 1 wt%, and the loading of the auxiliary agent CeO2 is 5 wt%.

[0082] The obtained catalyst was subjected to degassing pretreatment under the following conditions: 200℃, 300μmHg, 6h. Then, nitrogen physical adsorption-desorption tests were performed using an ASAP 2460 from Micromeritics at -196℃ in a liquid nitrogen bath.

[0083] The physical adsorption-desorption curve of the catalyst Figure 1 As shown, the pore size distribution of the catalyst is as follows: Figure 2 As shown, from Figure 1 and Figure 2 It can be seen that the specific surface area of ​​the Pd / 5%CeO2-C-Ar catalyst treated with cold plasma is 160-180 m². 2 / g, pore volume is 0.60~0.80cm³ 3 / g, with a pore size of 10–12 nm. The TEM characterization results of the catalyst are as follows: Figure 3As shown, Pd is uniformly distributed on CeO2-CNT.

[0084] Example 3

[0085] The catalyst prepared in Example 2 was used to dehydrogenate organic liquid hydrogen storage materials, and the method is as follows:

[0086] The organic liquid hydrogen storage material is perhydropropylcarbazole (PAC), the reaction temperature is 180℃, and the ratio of catalyst to PAC is 1:5. Complete dehydrogenation is achieved within 240 minutes, with a dehydrogenation amount of approximately 5.4 wt%. The amount of hydrogen released by this catalyst from the dehydrogenation of PAC is as follows: Figure 4 As shown.

[0087] Example 4

[0088] The organic liquid hydrogen storage material was used for cyclic dehydrogenation using the carbon-supported metal dehydrogenation catalyst prepared in Example 2, as follows:

[0089] The organic liquid hydrogen storage material was perhydropropylcarbazole, the reaction temperature was 180℃, the ratio of catalyst to perhydropropylcarbazole was 1:5, and 8 cycles of dehydrogenation were performed. Dehydrogenation data are as follows: Figure 5 As shown, from Figure 5 It can be seen that the dehydrogenation performance still maintains a high hydrogen release rate after 8 cycles.

[0090] Examples 5-8

[0091] According to the method of Example 2, the amounts of Ce(NO3)3·6H2O and CNT in step S1 were adjusted to obtain catalysts with CeO2 loadings of 1%, 3%, 7%, and 9%, respectively.

[0092] Because CeO2 itself has a low specific surface area, the specific surface area, pore volume, and pore size of the catalyst all decrease with increasing CeO2 content. The specific surface area of ​​the Pd / 1%CeO2-C-Ar catalyst is 200–205 m² / g. 2 / g, pore volume is 0.75~0.80cm³ 3 / g, with a pore size of 20-25nm.

[0093] The catalysts prepared in Examples 2, 5, 6, 7, and 8 were subjected to Raman spectroscopy, inductively coupled plasma atomic emission spectroscopy, and carbon monoxide pulsed chemisorption tests. The results are shown in Table 1.

[0094] Table 1

[0095]

[0096]

[0097] As shown in Table 1, after introducing low loadings (1, 3, 5 wt%) of CeO2, the particle size of Pd gradually decreased with increasing CeO2 content. However, further increasing the CeO2 content increased the particle size of Pd to approximately 3.4 nm. This indicates that excessively high CeO2 loading led to more active Pd particles directly settling on CeO2, resulting in a lower degree of aggregation during the reduction preparation process.

[0098] Example 9

[0099] A method for preparing a supported metal dehydrogenation catalyst based on a carbon material support, the steps of which are as described in Example 1.

[0100] The difference lies in the fact that the reaction gas introduced in step S4 of Example 9 is O2. The catalyst is designated as Pd / 5%CeO2-C-O2, and its specific surface area is 200-230 m². 2 / g, pore volume is 0.60~1.00cm³ 3 / g, with a pore size of 10-15nm.

[0101] Example 10

[0102] A method for preparing a supported metal dehydrogenation catalyst based on a carbon material support, the steps of which are as described in Example 1.

[0103] The difference lies in the fact that the reaction gas introduced in step S4 of Example 10 is H2. The catalyst is designated as Pd / 5%CeO2-C-H2, and its specific surface area is 160-170 m². 2 / g, pore volume is 0.50~0.75cm³ 3 / g, with a pore size of 10-12nm.

[0104] Example 11

[0105] A method for preparing a supported metal dehydrogenation catalyst based on a carbon material support, the steps of which are as described in Example 1.

[0106] The difference lies in step S4 of Example 11, which does not employ cold plasma treatment but instead uses a conventional thermal reduction method, specifically as follows: The catalyst precursor powder is transferred to a tube furnace and heated to 240°C at a rate of 5°C / min under a 10% H2 / Ar atmosphere, held for 2 hours, with a mixed gas flow rate of 70 mL / min. After cooling, the mixture is ground to obtain the catalyst. The catalyst is designated as Pd / 5%CeO2-C, with a specific surface area of ​​200–235 m². 2 / g, pore volume is 0.50~0.65cm³ 3 / g, with a pore size of 8-10nm.

[0107] The catalysts prepared in Examples 2, 9, 10, and 11 were analyzed by X-ray photoelectron spectroscopy (XPS), and all data were corrected to the C1s binding energy (284.80 eV). The obtained data are shown in Table 2.

[0108] Table 2

[0109]

[0110]

[0111] As shown in Table 2, compared with the catalyst treated with cold plasma, the catalyst prepared by the conventional thermal reduction method (Pd / 5%CeO2-C) cannot generate a large number of micro-positively charged noble metal particles Pd(II), which limits the dehydrogenation reaction. However, the catalyst treated with Ar gas cold plasma (Pd / 5%CeO2-C-Ar) generates more oxygen vacancies on the CeO2 surface, constructs a large number of CeO2-C interfaces, and effectively anchors more active noble metal components at the interface, generating a large number of micro-positively charged noble metal particles Pd(II), which promotes the desorption of the final dehydrogenation products and makes the catalytic reaction more efficient and sustainable.

[0112] Example 12

[0113] The catalysts prepared in Examples 2, 5, 6, 7, and 8 were subjected to ammonia-programmed temperature desorption (NH3-TPD) treatment. The specific steps are as follows:

[0114] S1 Purification: Approximately 50 mg of catalyst was placed under high-purity Ar conditions and heated from 50 °C to 200 °C at a heating rate of 10 °C / min for 1 hour to remove impurities from the catalyst.

[0115] After the S2 adsorption and impurity removal process is completed and the temperature is cooled to room temperature, the atmosphere is replaced with an NH3 / Ar mixed gas with an NH3 content of 10%, and the catalyst is allowed to fully adsorb at room temperature for 1 hour.

[0116] S3 desorption was performed, and the catalyst was heated to 800℃ at a heating rate of 10℃ / min in a high-purity Ar atmosphere. The NH3 content in the exhaust gas was recorded using a TCD.

[0117] NH3-TPD uses NH3 as a molecular probe to study the acidic properties of catalysts. The results are as follows: Figure 6As shown, the medium-strong acid sites at 200-400℃ are provided by the CeO2-C interface. With increasing CeO2 content, the content of medium-strong acid sites in the catalyst first gradually increases, then disappears entirely. This indicates that at low loadings (1, 3, 5 wt%), the CeO2-C interface gradually increases, allowing more surface-positively charged Pd(II) to settle at the interface. However, at 7 wt%, CeO2 becomes oversaturated, the CeO2-C interface disappears, and Pd(II) no longer settles at the interface but directly on the CeO2 surface, which is detrimental to the dehydrogenation reaction.

[0118] Example 13

[0119] The catalysts prepared in Examples 2, 9, 10, and 11 were subjected to hydrogen temperature-programmed desorption (H2-TPD) treatment, with the specific steps being the same as in Example 12;

[0120] The difference is that in S2, the atmosphere is changed to an H2 / Ar mixture with an H2 content of 10%, and the catalyst is allowed to fully adsorb at room temperature for 1 hour; in S3, the H2 content in the exhaust gas is recorded using a TCD.

[0121] H2-TPD uses H2 as a molecular probe to study the adsorption-dissociation ability of noble metal active components for hydrogen species. The results are as follows: Figure 7 As shown, the catalyst without cold plasma treatment exhibits only one desorption peak at around 100℃, attributed to hydrogen adsorption at weak adsorption sites on the surface. However, after cold plasma treatment with different atmospheres, two desorption peaks appear at both around 100℃ and 280℃. The former corresponds to hydrogen adsorption at weak adsorption sites, while the latter is due to hydrogen adsorption by surface-polarized Pd(II) at the CeO2-C interface. Pd / 5%CeO2-C-Ar exhibits the highest desorption peak in the higher temperature range (300-500℃) among all catalysts, demonstrating stronger hydrogen adsorption. This indicates that more surface-polarized Pd(II) lands at the CeO2-C interface, thus promoting a sustained and efficient dehydrogenation reaction.

[0122] Example 14

[0123] The catalysts prepared in Examples 2, 9, 10, and 11 were used in the dehydrogenation application of organic liquid hydrogen storage materials.

[0124] The organic liquid hydrogen storage material is perhydropropylcarbazole, the reaction temperature is 180℃, and the ratio of catalyst to perhydropropylcarbazole is 1:5. Figure 8 As shown, Pd / 5%CeO2-C-Ar exhibited the highest dehydrogenation rate, with a hydrogen release of 5.34 wt% at 360 min, achieving complete hydrogen release.

[0125] Comparative Example 1

[0126] Following the preparation method of Example 2, a catalyst was prepared by replacing S2 with CeO2-CNT using CNTs prepared in Example 1. The catalyst was designated Pd / C-Ar, and its specific surface area was 250–300 m². 2 / g, pore volume is 0.90~1.20cm³ 3 / g, with a pore size of 13-16nm.

[0127] experiment

[0128] The surface charge of the noble metal element Pd and the catalysts prepared in Examples 2, 5, 6, 7, 8, 9, 10, 11 and Comparative Example 1 was detected, and the results of the +2 valence micro-positive charge content are shown in Table 3.

[0129] Table 3

[0130]

[0131] As shown in Table 3, both the CeO2 promoter and cold plasma atmosphere treatment can increase the content of micro-positively charged Pd(II). The Pd / 5%CeO2-C-Ar catalyst in Example 2 has the highest micro-positive charge content and is effectively anchored at the CeO2-CNT interface. The micro-positively charged noble metal particles Pd(II) enhance the dehydrogenation reaction rate, and the CeO2 promoter can quickly replenish the consumption generated during the reaction. The synergistic effect of the two greatly enhances the activity and cycle stability of the catalyst, promoting the rapid and complete dehydrogenation reaction.

[0132] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a supported metal type dehydrogenation catalyst based on a carbon material carrier, characterized by, Includes the following steps: S1. The additive precursor and the carrier are mixed in a dispersant, ultrasonicated, stirred, evaporated to dryness, calcined in an inert gas, and cooled to room temperature to obtain the additive-carrier. S2. The additive-carrier and the noble metal precursor are mixed in the dispersant, stirred, evaporated, and dried in an oven to obtain the catalyst precursor; S3. Place the catalyst precursor into a cold plasma reactor, introduce reaction gas to react fully, and obtain the supported metal dehydrogenation catalyst based on carbon material support. The reacting gas mentioned in step S3 is any one of O2, H2, and Ar; The carbon-supported metal dehydrogenation catalyst comprises the following components by mass percentage: Carrier 88.5%~98.5%, precious metals 0.5%~2.5%, additives 1%~5%; The support is an activated carbon material; the carbon material is at least one of C 60 , CNT, CDs. The precious metal is at least one of Pd, Pt, Ru, and Rh; The auxiliary agent is at least one of elemental Ce or its oxide; The precious metal has a 75% to 90% surface charge and is effectively anchored at the additive-carrier interface.

2. The method for producing a supported metal type dehydrogenation catalyst based on a carbon material carrier according to claim 1, characterized by, The specific surface area of the catalyst is 150-250 m 2 / g, the pore volume is 0.60-1.00 cm 3 / g, and the pore diameter is 10-15 nm.

3. The method for producing a supported metal type dehydrogenation catalyst based on a carbon material carrier according to claim 1, characterized by, The method for preparing the carrier is as follows: (1) Mix the alkali and carbon material in a dispersant, stir thoroughly and evaporate to dryness, then calcine in an inert gas at 800°C for 1-2 hours to obtain alkali-treated carbon material; (2) Cool the alkali-treated carbon material, dissolve it in the same dispersant, and add acid dropwise to obtain acid-treated carbon material; (3) The acid-treated carbon material is washed, dried and ground to obtain a carrier.

4. The method for producing a supported metal type dehydrogenation catalyst based on a carbon material carrier according to claim 3, characterized by, The alkali is any one of potassium hydroxide, sodium hydroxide, and ammonia water; the dispersant is any one of water, ethanol, and acetone; the inert gas is any one of nitrogen and argon; and the acid is any one of hydrochloric acid, sulfuric acid, and nitric acid. The mass ratio of alkali, carbon material, and dispersant in step (1) is 1~5:1:20; In step (2), the mass ratio of the alkali-treated carbon material, dispersant, and acid is 1:20:8~10.

5. The method for preparing a carbon-supported metal dehydrogenation catalyst according to claim 1, characterized in that, The precursor of the auxiliary agent mentioned in step S1 is an organic or inorganic salt of the auxiliary agent; the dispersant is any one of water, ethanol, and acetone; the inert gas is any one of nitrogen and argon. The mass ratio of the auxiliary agent precursor, carrier, and dispersant is 20~25:170~180:50000; The roasting temperature is 450~500℃.

6. The method for preparing a supported metal type dehydrogenation catalyst based on a carbon material carrier according to claim 1, characterized by, In step S2, the noble metal precursor is an organic or inorganic salt of a noble metal; the dispersant is any one of water, ethanol, and acetone. The ratio of the additive-carrier, the noble metal precursor and the dispersant is 95~100:1:1950~2000.

7. The method for preparing a supported metal type dehydrogenation catalyst based on a carbon material carrier according to claim 1, characterized by, The output voltage of the cold plasma in step S3 is 80~120V.

8. Use of a supported metal-based dehydrogenation catalyst prepared according to the method of claim 1, characterized in that, Application of the catalyst in the catalytic dehydrogenation reaction of organic liquid hydrogen storage materials; The organic liquid hydrogen storage material is a mixture of any one or more of the following: perhydronitropropylcarbazole, perhydronitroethylcarbazole, perhydrodibenzyltoluene, perhydro1-methylindole, and perhydro1,2-dimethylindole.

9. Use of a supported metal dehydrogenation catalyst based on a carbon material carrier according to claim 8, characterized in that The temperature of the catalytic dehydrogenation reaction is 100℃~400℃, the mass ratio of catalyst to organic liquid hydrogen storage material is 1:5~5:1, and the reaction time is 0~400min, excluding 0.

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