Hydrogenation and dehydrogenation of heterocyclic organic liquid hydrogen storage carriers

Abstract

The application discloses a hydrogenation and dehydrogenation method of a heterocyclic organic liquid hydrogen storage carrier, which utilizes a heterocyclic organic liquid and hydrogen to carry out a hydrogenation reaction to obtain a saturated organic condensate liquid, and a dehydrogenation process is adopted to remove hydrogen in the saturated organic condensate liquid through catalytic pyrolysis, and the regeneration and recycling of the unsaturated organic liquid are simultaneously realized; the hydrogenation and dehydrogenation process adopts Ru-based multi-component catalyst catalysis; the catalyst of the application can finely control the selectivity of the reaction under the premise of ensuring the reaction activity, can overcome the problems of low hydrogenation and dehydrogenation activity of the catalyst, carbon deposition and deactivation of the catalyst in the hydrogenation and dehydrogenation process and the like existing in the prior art, has high hydrogenation and dehydrogenation activity and stability, improves the purity of hydrogen, and simultaneously realizes the regeneration of the unsaturated organic liquid. The process has the advantages of simple process, low operation cost, mild hydrogenation and dehydrogenation conditions, repeated recycling of the organic liquid, no impurity gas in the dehydrogenation process, high operation stability and the like.

Description

Technical Field

[0001] This invention belongs to the field of organic liquid hydrogen storage technology, specifically relating to methods for hydrogenation and dehydrogenation of heterocyclic organic liquid hydrogen storage carriers. Background Technology

[0002] Hydrogen storage technology has always been a bottleneck in the development of hydrogen energy applications. Currently, commercially available hydrogen storage methods mainly include high-pressure gaseous hydrogen storage and cryogenic liquefaction hydrogen storage. Both methods have significant disadvantages: high cost of storage equipment, harsh operating environments and conditions, significant hydrogen loss during use, low safety factor, high accident risk, expensive infrastructure construction for large-scale deployment, and difficulties in distribution and transportation. Against this backdrop, organic liquid hydrogen storage technology has been proposed as a novel hydrogen storage technology. It utilizes a reversible addition and dehydrogenation reaction between an organic liquid hydrogen storage carrier containing unsaturated bonds and hydrogen to achieve hydrogen storage. It can leverage existing infrastructure for fossil fuel transportation and use, offering convenient storage, safe operation, and low supply chain construction costs.

[0003] Most existing organic liquid hydrogen storage processes involve harsh conditions for hydrogenation and dehydrogenation, low dehydrogenation efficiency due to catalyst performance limitations, short lifespan of organic liquids, and low hydrogen purity. Summary of the Invention

[0004] The purpose of this invention is to provide a method for hydrogenation and dehydrogenation of heterocyclic organic liquid hydrogen storage carriers, which solves the problems of short service life of organic liquids and low activity of catalysts for hydrogenation and dehydrogenation in hydrogen storage processes.

[0005] The technical solution adopted in this invention is a method for hydrogenation and dehydrogenation of a heterocyclic organic liquid hydrogen storage carrier. The method utilizes the hydrogenation reaction between the heterocyclic organic liquid and hydrogen to obtain a saturated organic condensate, while the dehydrogenation process uses catalytic thermal desorption to remove hydrogen from the saturated organic condensate, and simultaneously realizes the regeneration and recycling of the unsaturated organic liquid. The hydrogenation and dehydrogenation processes are catalyzed by a Ru-based multi-component catalyst.

[0006] The invention is further characterized in that,

[0007] The specific steps for hydrogenation and dehydrogenation of heterocyclic organic liquid hydrogen storage carriers are as follows:

[0008] A Ru-based multi-component catalyst was loaded into a hydrogenation reactor and a dehydrogenation reactor, respectively. The catalyst was reduced in the reactor at atmospheric pressure and a pure hydrogen atmosphere at 200-300℃ for 3-6 hours. After reduction, the hydrogen was switched to nitrogen, and the heterocyclic organic liquid was added to the hydrogenation reactor through a liquid injection pump. Hydrogen was injected under pressure, and the hydrogenation reaction was carried out at 100-150℃ and 2-6 MPa. After hydrogenation, the obtained saturated organic condensate was added to the dehydrogenation reactor. The catalyst for the dehydrogenation reaction was a Ru-based multi-component catalyst, and the dehydrogenation reaction was carried out at 200-300℃ and 0.1 MPa. After the hydrogenation and dehydrogenation reactions were completed, the residual liquid phase and the generated gas were qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively.

[0009] The nitrogen flow rate is 100-200 mL / min; the heterocyclic organic liquid is one of dibenzyltoluene and N-ethylcarbazole.

[0010] The specific preparation method of Ru-based multi-component catalyst is as follows:

[0011] Step 1: Pretreatment of carbon support

[0012] The carbon support was placed in a flask, vacuumed, and then deionized water was slowly added. H2O2 was then added and stirred with a magnetic stirrer for 1-5 hours. After the suspension was allowed to stand for 10-24 hours, it was centrifuged at 4000-10000 r / min. The precipitate was dried at 80℃-100℃ and ground for later use. The volume ratio of deionized water to hydrogen peroxide (H2O2) was 1:1.

[0013] Step 2: Heteroatom treatment of carbon support

[0014] The carbon support and heteroatom reducing agent treated in step 1 were mixed and ground using a hydrothermal method. Deionized water was added and the mixture was magnetically stirred for 20-60 minutes. The mixture was then transferred to a hydrothermal reactor and hydrothermally reacted at 100-200℃ for 15-30 hours. After centrifugation and washing three times with deionized water, the mixture was dried to obtain precursor powder. The precursor powder was then placed in a tube furnace and calcined at 550-700℃ for 2-6 hours under nitrogen protection to obtain heteroatom-doped carbon material. The mass ratio of carbon support to heteroatom reducing agent was 1:4.

[0015] Step 3: Synthesis of carbon-supported Ru-based catalyst

[0016] The heteroatom-doped carbon material described in step 3 was added to the Ru active component aqueous solution by ion exchange method, and ion exchange was carried out in a water bath at 70-85℃. After filtration, washing, drying, and calcination in a muffle furnace, the catalyst precursor was obtained.

[0017] Step 4: Transition metal modified catalyst

[0018] The catalyst precursor was added to the aqueous solution of the auxiliary agent by the equal volume impregnation method, and then aged, dried and calcined at room temperature to obtain the Ru-based multi-component catalyst.

[0019] The carbon support mentioned in step 1 is either carbon nanotubes or carbon black.

[0020] The heteroatom reducing agent in step 2 is either triphenylphosphine or melamine.

[0021] The method for preparing the Ru active component aqueous solution in step 3 is as follows: weigh ruthenium chloride and prepare an aqueous solution of the active component with a concentration of 0.5-2.0 mol / L;

[0022] The ratio of the heteroatom-doped carbon material to the Ru active component aqueous solution in step 3 is 1g:6ml;

[0023] The drying temperature in step 3 is 95-110℃, the drying time is 7h-12h, and the drying is carried out in a muffle furnace, including raising the furnace temperature to 550-750℃ at a rate of 2℃ / min-5℃ / min and holding it for 6h-12h.

[0024] In step 4, the auxiliary metal sources are Fe, Co, Ni, Zr, and Ce.

[0025] In step 4, the aging time at room temperature is 15-30 hours, the drying temperature is 80-110℃, the drying time is 10-18 hours, the heating rate of calcination is 2℃ / min-8℃ / min, the calcination temperature is 500-750℃, and the calcination time is 6-15 hours.

[0026] In step 4, an aqueous solution of the additive is prepared. Based on the total mass of the catalyst, the loading of the additive is 0.5-5.0%wt. The additive metal source is weighed according to the additive loading and the aqueous solution of the additive is prepared.

[0027] This invention selects stable and efficient heterocyclic aromatic hydrocarbons as hydrogen storage carriers, achieving reversible hydrogen storage cycles of hydrogenation and dehydrogenation below 300°C. The hydrogen release process produces almost no poisoning of impurity gas components used in downstream fuel cells, and the carrier can be recycled and reused multiple times, demonstrating significant advantages over other hydrogen storage materials. Simultaneously, a multi-component catalyst is synthesized. By adding different components and adjusting their ratios, the selectivity of the reaction can be precisely controlled while maintaining reactivity. This overcomes the problems of low hydrogenation and dehydrogenation activity and carbon deposition and deactivation during hydrogenation and dehydrogenation in existing technologies, exhibiting high hydrogenation and dehydrogenation activity and stability, improving hydrogen purity, and significantly reducing costs.

[0028] The beneficial effects of this invention are:

[0029] This invention selects a stable and efficient heterocyclic organic liquid as a hydrogen storage carrier, achieving reversible hydrogen storage cycles of hydrogenation and dehydrogenation below 300°C. The hydrogen release process produces almost no poisoning of impurity gas components used in downstream fuel cells, and the carrier can be recycled and reused multiple times, demonstrating significant advantages over other hydrogen storage materials. Simultaneously, a carbon-supported Ru-based multi-component catalyst is synthesized, with Ru loading exceeding 40%, improving the utilization rate of the precious metal. Furthermore, the catalyst's hydrogenation and dehydrogenation activity and stability are enhanced, allowing for precise control of reaction selectivity while maintaining reactivity. This overcomes the problems of low catalyst hydrogenation and dehydrogenation activity and carbon deposition and deactivation during hydrogenation and dehydrogenation processes in existing technologies. It exhibits high hydrogenation and dehydrogenation activity and stability, improves hydrogen purity, and significantly reduces costs. Attached Figure Description

[0030] Figure 1 This is a flowchart of the hydrogenation and dehydrogenation method for the heterocyclic organic liquid hydrogen storage carrier of the present invention;

[0031] Figure 2 This is a schematic diagram of the dehydrogenation and hydrogenation reaction of dibenzyltoluene according to the present invention; Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0033] The first key innovation of this invention is that it selects a stable and efficient heterocyclic organic liquid as a hydrogen storage carrier, realizes reversible hydrogen storage cycle of hydrogenation and dehydrogenation below 300°C, and achieves the purpose of recyclable and reusable hydrogen storage carrier.

[0034] The second key innovation of this invention lies in the use of a Ru-based multi-component catalyst, with Ru as the active component, transition metals as promoters, and carbon materials as the catalyst support. The carbon support is treated with heteroatoms, coating its surface with reducing compounds containing heteroatoms. Pyrolysis of these compounds forms heteroatom-modified carbon surfaces, serving as targets for Ru particle nucleation and growth. This heteroatom treatment significantly increases the Ru loading on the carbon support while reducing the amount of precious metals used, thus lowering the catalyst synthesis cost. Introducing heteroatoms into the carbon support disrupts its structure, introducing numerous defect sites, regulating the microscopic electronic structure of the carbon material, promoting charge delocalization, and improving reaction kinetics. Furthermore, the introduction of heteroatoms improves the interaction between the metal and the support, enhancing the support's ability to anchor metal atoms and increasing the intrinsic activity of the metal active sites. Simultaneously, adding different metal components as promoters and adjusting the component ratios allows for precise control of reaction selectivity while maintaining reactivity, overcoming the low hydrogenation and dehydrogenation activity problems of existing catalysts.

[0035] Example 1

[0036] like Figure 1-2 As shown, the Ru-based multi-component catalyst was loaded into a hydrogenation reactor and a dehydrogenation reactor, respectively. The catalyst was reduced at atmospheric pressure in the reactors at 200°C for 6 hours under a pure hydrogen atmosphere at atmospheric pressure. After the reduction was completed, the hydrogen gas was switched to nitrogen gas at a flow rate of 100 mL / min, and dibenzyltoluene was added to the hydrogenation reactor via a liquid injection pump at a space velocity of 10 h⁻¹. -1 Hydrogen was injected under pressure, and the hydrogenation reaction was carried out at 100℃ and 6MPa. After hydrogenation, a portion of the condensate was sampled for analysis, while the remainder was carried into the dehydrogenation reactor under nitrogen. The catalyst for the dehydrogenation reaction was a Ru-based multi-component catalyst, and the dehydrogenation reaction was carried out at 200℃ and 0.1MPa. After the hydrogenation and dehydrogenation reactions were completed, the composition of the residual liquid phase and the generated gas was qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively (Table 2).

[0037] The method for preparing the Ru-based multi-component catalyst used in Example 1 of this invention is as follows:

[0038] Step 1. Pretreatment of carbon support

[0039] Weigh 10g of carbon nanotubes into a three-necked round-bottom flask, slowly add 100mL of deionized water, then add 100mL of H2O2 and stir with a magnetic stirrer for 1h; after the suspension has stood for 10h, centrifuge at 10000r / min, dry the precipitate at 80℃, and grind it for later use.

[0040] The carbon support mentioned in step 1 is either carbon nanotubes or carbon black.

[0041] Step 2. Heteroatom treatment of carbon support

[0042] A hydrothermal method was used to combine 5g of carbon nanotubes treated in step 1 and 20g of triphenylphosphine. Deionized water was added, and the mixture was stirred magnetically for 20 min. The mixture was then transferred to a 500mL hydrothermal reactor and hydrothermally reacted at 100℃ for 30 h. After centrifugation and washing three times with deionized water, the mixture was dried to obtain precursor powder. The precursor powder was placed in a tube furnace and calcined at 700℃ for 2 h under nitrogen protection to obtain heteroatom-doped carbon materials.

[0043] Step 3. Synthesis of carbon-supported Ru-based catalyst

[0044] The catalyst precursor was synthesized by ion exchange: 41.5 g of ruthenium chloride was weighed and added to a 200 mL volumetric flask to prepare a 1.0 mol / L aqueous solution. Ion exchange was carried out in a 70 °C water bath, followed by filtration and washing. The drying temperature was 95 °C and the drying time was 12 h. The precursor was then calcined in a muffle furnace, including raising the furnace temperature to 550 °C at a rate of 2 °C / min and holding it for 12 h to obtain the catalyst precursor.

[0045] Step 4. Transition metal modified catalyst

[0046] Weigh 1.37g of zirconium nitrate to prepare an aqueous solution of the additive with a loading of 0.5%wt. Add the catalyst precursor to the aqueous solution of the additive using an equal-volume impregnation method. Allow it to stand at room temperature for 15h, dry at 80℃ for 18h, and calcine at a heating rate of 2℃ / min for 500℃ for 15h to obtain the Ru-based multi-component catalyst.

[0047] Example 2

[0048] The Ru-based multi-component catalyst prepared in Example 1 was used in the reaction;

[0049] The Ru-based multi-component catalyst was loaded into both a hydrogenation reactor and a dehydrogenation reactor. The catalyst was then reduced at atmospheric pressure in both reactors under a pure hydrogen atmosphere at 250°C for 4 hours. After reduction, the hydrogen gas was switched to nitrogen at a flow rate of 150 mL / min. Dibenzyltoluene was then added to the hydrogenation reactor via a liquid injection pump at a space velocity of 20 h⁻¹. -1 Hydrogen gas was injected under pressure, and the hydrogenation reaction was carried out at 120°C and 4 MPa.

[0050] After hydrogenation, a portion of the reactant condensate was sampled for analysis (Table 1), while the remainder was carried into the dehydrogenation reactor under nitrogen gas. The dehydrogenation reaction was carried out at 250 °C and 0.1 MPa using a Ru-based multi-component catalyst. After the hydrogenation and dehydrogenation reactions were completed, the composition of the residual liquid phase and the generated gas was qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively (Table 2).

[0051] Example 3

[0052] The Ru-based multi-component catalyst prepared in Example 1 was used in the reaction;

[0053] The Ru-based multi-component catalyst was loaded into both the hydrogenation and dehydrogenation reactors. The catalyst was then reduced at atmospheric pressure in both reactors under a pure hydrogen atmosphere at 300°C for 3 hours. After reduction, the hydrogen gas was switched to nitrogen at a flow rate of 200 mL / min. Dibenzyltoluene was then added to the hydrogenation reactor via a liquid injection pump at a space velocity of 30 h⁻¹. -1 Hydrogen gas was injected under pressure, and the hydrogenation reaction was carried out at 150°C and 2 MPa.

[0054] After hydrogenation, a portion of the reactant condensate was sampled for analysis (Table 1), while the remainder was carried into the dehydrogenation reactor under nitrogen gas. The catalyst for the dehydrogenation reaction was a Ru-based multi-component catalyst, and the dehydrogenation reaction was carried out at 300℃ and 0.1 MPa. After the hydrogenation and dehydrogenation reactions were completed, the composition of the residual liquid phase and the generated gas was qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively (Table 2).

[0055] Example 4

[0056] The Ru-based multi-component catalyst was loaded into both a hydrogenation reactor and a dehydrogenation reactor. The catalyst was then reduced at atmospheric pressure in both reactors under a pure hydrogen atmosphere at 250°C for 4 hours. After reduction, the hydrogen gas was switched to nitrogen at a flow rate of 150 mL / min. Dibenzyltoluene was then added to the hydrogenation reactor via a liquid injection pump at a space velocity of 20 h⁻¹. -1 Hydrogen gas was injected under pressure, and the hydrogenation reaction was carried out at 120°C and 4 MPa.

[0057] After hydrogenation, a portion of the reactant condensate was sampled for analysis (Table 1), while the remainder was carried into the dehydrogenation reactor under nitrogen gas. The dehydrogenation reaction was carried out at 250 °C and 0.1 MPa using a Ru-based multi-component catalyst. After the hydrogenation and dehydrogenation reactions were completed, the composition of the residual liquid phase and the generated gas was qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively (Table 2).

[0058] The method for preparing the Ru-based multi-component catalyst used in Example 4 of this invention is as follows:

[0059] Step 1. Pretreatment of carbon support

[0060] Weigh 10g of carbon black into a three-necked round-bottom flask, slowly add 100mL of deionized water, then add 100mL of H2O2 and stir with a magnetic stirrer for 5h. After the suspension has stood for 24h, centrifuge at 4000r / min, dry the precipitate at 100℃, and grind it for later use.

[0061] Step 2. Heteroatom treatment of carbon support

[0062] A hydrothermal synthesis method was adopted. 5g of treated carbon black and 20g of melamine were mixed, deionized water was added, and the mixture was stirred magnetically for 60 min. The mixture was then transferred to a 500mL hydrothermal reactor and hydrothermally reacted at 200℃ for 15 h. After centrifugation and washing three times with deionized water, the precursor powder was obtained. The precursor powder was placed in a tube furnace and calcined at 550℃ for 6 h under nitrogen protection to obtain heteroatom-doped carbon materials.

[0063] Step 3. Synthesis of carbon-supported Ru-based catalyst

[0064] The catalyst precursor was synthesized by ion exchange. 20.7 g of ruthenium chloride was weighed and added to a 200 mL volumetric flask to prepare a 0.5 mol / L aqueous solution. Ion exchange was carried out in an 85 °C water bath, followed by filtration and washing. The drying temperature was 110 °C and the drying time was 7 h. The precursor was then calcined in a muffle furnace, including raising the furnace temperature to 750 °C at a rate of 5 °C / min and holding it for 6 h to obtain the catalyst precursor.

[0065] Step 4. Transition metal modified catalyst

[0066] Weigh 13.7g of zirconium nitrate to prepare an aqueous solution of the additive with a loading of 5.0%wt. Add the catalyst precursor to the aqueous solution of the additive using an equal-volume impregnation method. Allow it to stand at room temperature for 30h, dry at 110℃ for 10h, and calcine at a heating rate of 8℃ / min for 750℃ for 6h to obtain the Ru-based multi-component catalyst.

[0067] Example 5

[0068] Hydrogenation was carried out in a fixed-bed reactor, using N-ethylcarbazole as the heterocyclic organic liquid, with other conditions the same as in Example 3; the dehydrogenation reaction was also the same as in Example 3.

[0069] The method for preparing the Ru-based multi-component catalyst used in Example 5 of this invention is as follows:

[0070] Step 1. Pretreatment of carbon support

[0071] Weigh 10g of carbon nanotubes into a three-necked round-bottom flask, slowly add 100mL of deionized water, then add 100mL of H2O2 and stir magnetically for 3h. After the suspension has stood for 18h, centrifuge at 6000r / min, dry the precipitate at 95℃, and grind it for later use.

[0072] Step 2. Heteroatom treatment of carbon support

[0073] A hydrothermal synthesis method was adopted. 5g of treated carbon nanotubes and 20g of melamine were mixed, deionized water was added, and the mixture was stirred magnetically for 40 min. The mixture was then transferred to a 500mL hydrothermal reactor and hydrothermally reacted at 150℃ for 20 h. After centrifugation and washing three times with deionized water, the precursor powder was obtained. The precursor powder was placed in a tube furnace and calcined at 600℃ for 5 h under nitrogen protection to obtain heteroatom-doped carbon materials.

[0074] Step 3. Synthesis of carbon-supported Ru-based catalyst

[0075] The catalyst precursor was synthesized by ion exchange. 82.9 g of ruthenium chloride was weighed and added to a 200 mL volumetric flask to prepare a 2.0 mol / L aqueous solution. Ion exchange was carried out in an 80 °C water bath, followed by filtration and washing. The drying temperature was 105 °C and the drying time was 9 h. The precursor was then calcined in a muffle furnace, including raising the furnace temperature to 700 °C at a rate of 3 °C / min and holding it for 8 h to obtain the catalyst precursor.

[0076] Step 4. Transition metal modified catalyst

[0077] Weigh 0.95g of cerium nitrate to prepare an aqueous solution of the additive with a loading of 0.5%wt. Add the catalyst precursor to the aqueous solution of the additive using an equal-volume impregnation method. Allow it to stand at room temperature for 20h, dry at 100℃ for 12h, and calcine at a heating rate of 5℃ / min for 700℃ for 9h to obtain the Ru-based multi-component catalyst.

[0078] Example 6

[0079] The hydrogenation reaction conditions were the same as in Example 5. The organic liquid hydrogen storage material was N-ethylcarbazole. After the catalyst and organic liquid were repeatedly subjected to hydrogenation and dehydrogenation reactions for 1000 h, the composition of the residual liquid phase and the generated gas was qualitatively and quantitatively analyzed by GC MS and gas chromatography, respectively.

[0080] The Ru-based multi-component catalyst used in Example 6 of this invention is the same as that in Example 5.

[0081] Example 7

[0082] The hydrogenation reaction conditions were the same as in Example 2. The organic liquid hydrogen storage material was dibenzyltoluene. After repeated hydrogenation and dehydrogenation reactions of the catalyst and organic liquid for 1000 h, the composition of the residual liquid phase and the generated gas was qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively. The dehydrogenation reaction was the same as in Example 2.

[0083] The Ru-based multi-component catalyst used in Example 7 of this invention is the same as that in Example 2.

[0084] Table 1. Experimental results after hydrogenation reaction

[0085]

[0086] Table 2 Results of dehydrogenation reaction

[0087]

[0088]

[0089] The comparative results of the above embodiments show that the present invention selects a stable and efficient heterocyclic organic liquid as a hydrogen storage carrier, achieving reversible hydrogen storage cycles of hydrogenation and dehydrogenation below 300°C. Furthermore, the hydrogen release process produces almost no poisoning of impurity gas components used in downstream fuel cells, and the carrier can be recycled and reused multiple times, demonstrating significant advantages over other hydrogen storage materials. Simultaneously, a multi-component catalyst is synthesized. By adding different components and adjusting their ratios, the selectivity of the reaction can be precisely controlled while ensuring reactivity. This overcomes the problems of low catalyst activity during hydrogenation and dehydrogenation, and carbon deposition and deactivation during hydrogenation and dehydrogenation in existing technologies. The catalyst exhibits high hydrogenation and dehydrogenation activity and stability, improves hydrogen purity, and significantly reduces costs.

[0090] First, after multiple cycles, the hydrogen storage carrier of this invention maintains a conversion rate of over 84.6% and a selectivity of over 90.1%. The conversion rate indicates the efficiency of catalytic hydrogenation of organic liquids; under the catalysis of this catalyst, almost all unsaturated organic liquids are hydrogenated into saturated organic liquids. The selectivity indicates fewer side reactions under the action of this catalyst, with hydrogenation being the dominant reaction. Both of these indicators verify the excellent hydrogenation / dehydrogenation performance of this catalyst.

[0091] Secondly, the catalyst of the present invention has high hydrogenation and dehydrogenation efficiency, few by-products, less poisoning of organic liquid heterocycles, and can be reused many times, thus having a long service life.

Claims

1. A method for hydrogenation and dehydrogenation of a heterocyclic organic liquid hydrogen storage carrier, characterized by, A saturated organic condensate is obtained by hydrogenating a heterocyclic organic liquid with hydrogen, while a dehydrogenation process is used to remove hydrogen from the saturated organic condensate using catalytic thermal desorption, thereby regenerating and recycling the unsaturated organic liquid. The hydrogenation and dehydrogenation processes are catalyzed by a Ru-based multi-component catalyst. The specific preparation method of the Ru-based multi-component catalyst is as follows: Step 1: Pretreatment of carbon support The carbon support was placed in a flask, vacuumed, and deionized water was slowly added. Then H2O2 was added and the mixture was stirred with a magnetic stirrer for 1-5 hours. After the suspension was allowed to stand for 10-24 hours, it was centrifuged at 4000-10000 r / min. The precipitate was dried at 80℃-100℃ and ground for later use. Step 2: Heteroatom treatment of carbon support The carbon support and heteroatom reducing agent treated in step 1 were mixed and ground using a hydrothermal method. Deionized water was added and the mixture was magnetically stirred for 20-60 min. The mixture was then transferred to a hydrothermal reactor and hydrothermally reacted at 100-200℃ for 15-30 h. After centrifugation and washing with deionized water three times, the mixture was dried to obtain precursor powder. The precursor powder was then placed in a tube furnace and calcined at 550-700℃ for 2-6 h under nitrogen protection to obtain heteroatom-doped carbon material. Step 3: Synthesis of carbon-supported Ru-based catalyst The heteroatom-doped carbon material described in step 3 was added to the Ru active component aqueous solution by ion exchange method, and ion exchange was carried out in a water bath at 70-85℃. After filtration, washing, drying, and calcination in a muffle furnace, the catalyst precursor was obtained. Step 4: Transition metal modified catalyst The catalyst precursor was added to the aqueous solution of the auxiliary agent by the equal volume impregnation method, and then aged, dried and calcined at room temperature to obtain the Ru-based multi-component catalyst.

2. The method of claim 1, wherein the hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier is carried out at a temperature of 100 to 300°C and a pressure of 0.1 to 10 MPa. The specific steps are as follows: A Ru-based multi-component catalyst was loaded into a hydrogenation reactor and a dehydrogenation reactor, respectively. The catalyst was reduced in the reactor at atmospheric pressure and a pure hydrogen atmosphere at 200-300℃ for 3-6 hours. After reduction, the hydrogen was switched to nitrogen, and the heterocyclic organic liquid was added to the hydrogenation reactor through a liquid injection pump. Hydrogen was injected under pressure, and the hydrogenation reaction was carried out at 100-150℃ and 2-6 MPa. After hydrogenation, the obtained saturated organic condensate was added to the dehydrogenation reactor. The catalyst for the dehydrogenation reaction was a Ru-based multi-component catalyst, and the dehydrogenation reaction was carried out at 200-300℃ and 0.1 MPa. After the hydrogenation and dehydrogenation reactions were completed, the residual liquid phase and the generated gas were qualitatively and quantitatively analyzed by GC-MS and gas chromatography, respectively.

3. The method for hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier according to claim 2, characterized in that, The nitrogen flow rate is 100-200 mL / min; the heterocyclic organic liquid is one of dibenzyltoluene and N-ethylcarbazole.

4. The method of claim 1, wherein the hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier is carried out at a temperature of 100 to 300°C and a pressure of 0.1 to 10 MPa. The carbon support mentioned in step 1 is either carbon nanotube or carbon black; the volume ratio of deionized water and H2O2 mentioned in step 1 is 1:

1.

5. The method of claim 1, wherein the hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier is carried out at a temperature of 100 to 300°C and a pressure of 0.1 to 10 MPa. The heteroatom reducing agent in step 2 is either triphenylphosphine or melamine; the mass ratio of the carbon support and the heteroatom reducing agent in step 2 is 1:

4.

6. The method of claim 1, wherein the hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier is carried out at a temperature of 100 to 300°C and a pressure of 0.1 to 10 MPa. The method for preparing the Ru active component aqueous solution in step 3 is as follows: Weigh ruthenium chloride and prepare an aqueous solution of the active component with a concentration of 0.5-2.0 mol / L; The ratio of the heteroatom-doped carbon material to the Ru active component aqueous solution in step 3 is 1g:6ml; The drying temperature in step 3 is 95-110℃, the drying time is 7h-12h, and the calcination is carried out in a muffle furnace, including raising the furnace temperature to 550-750℃ at a rate of 2℃ / min-5℃ / min and holding it for 6h-12h.

7. The method for hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier according to claim 1, characterized in that, In step 4, the auxiliary metal sources are Fe, Co, Ni, Zr, and Ce.

8. The method of claim 1, wherein the hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier is carried out at a temperature of 100 to 300°C and a pressure of 0.1 to 10 MPa. In step 4, the aging time at room temperature is 15-30 hours, the drying temperature is 80-110℃, the drying time is 10-18 hours, the heating rate of calcination is 2℃ / min-8℃ / min, the calcination temperature is 500-750℃, and the calcination time is 6-15 hours.

9. The method of claim 1, wherein the hydrogenation and dehydrogenation of the heterocyclic organic liquid hydrogen storage carrier is carried out at a temperature of 100 to 300°C and a pressure of 0.1 to 10 MPa. In step 4, an aqueous solution of the additive is prepared. Based on the total mass of the catalyst, the loading of the additive is 0.5-5.0%wt. The metal source of the additive is weighed according to the loading of the additive, and the aqueous solution of the additive is prepared.

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