A hydrogen peroxide large-scale efficient electrochemical hydrogen storage and release system and method

Abstract

The application discloses a hydrogen peroxide large-scale efficient electrochemical hydrogen storage and release system and method, and belongs to the hydrogen storage technical field.The hydrogen storage module of the system is used for working when hydrogen is input at an anode and air / oxygen is input at a cathode, and the cathode of the hydrogen storage module can catalyze hydrogen to generate hydrogen peroxide; the hydrogen release module is used for working when the hydrogen peroxide storage module transports hydrogen peroxide to the anode of the hydrogen release module and direct current is connected, and the anode of the hydrogen release module can catalyze hydrogen peroxide to release hydrogen; the AC / DC conversion module is used for converting direct current generated when the hydrogen storage module works into alternating current which can be connected to an alternating current bus, or converting alternating current of the alternating current bus into direct current which can be used for working of the hydrogen release module.The hydrogen peroxide large-scale efficient electrochemical hydrogen storage and release system can realize long-term large-scale hydrogen storage at normal temperature and pressure, is complementary coupled with a renewable energy power grid to realize peak clipping and valley filling, links and fuses hydrogen energy and a multi-energy system, and has high energy efficiency in the hydrogen storage and release process.

Description

Technical Field

[0001] This invention relates to the field of hydrogen storage technology, specifically to a large-scale, high-efficiency electrochemical hydrogen storage and release system and method for hydrogen peroxide. Background Technology

[0002] In a carbon-neutral scenario, the proportion of renewable energy is increasing. However, the randomness and intermittency of renewable energy power make grid connection, regulation, consumption, and storage difficult. Hydrogen energy, as an energy storage medium, can provide an important pathway for renewable energy consumption and grid peak shaving, thereby supporting the construction of new smart grid systems. Renewable energy consumption can be achieved through renewable energy hydrogen production, storage, and utilization; and renewable energy hydrogen production, storage, and power generation can provide the grid with a new type of flexible regulation resource to meet the system's long-term and short-term peak shaving needs.

[0003] Hydrogen storage is a key technology for the interconnection of hydrogen energy with renewable energy sources, hydrogen usage scenarios, and the power grid. Current hydrogen storage technologies include cryogenic liquid hydrogen storage, high-pressure hydrogen storage, solid-state hydrogen storage, and organic-liquid-state hydrogen storage. These types of hydrogen storage technologies rely on processes such as thermochemical reactions or mechanical work, and there is a net energy consumption in the hydrogen storage-dehydrogenation cycle, requiring the use of complex thermal management systems to improve energy efficiency.

[0004] Electrochemical hydrogen storage technology is characterized by low cost, low energy consumption, flexible operation, and rapid hydrogen storage and release response. In particular, the energy input and output during the hydrogen storage and release process can be complementaryly coupled with the power grid to enhance system energy. It is a high-efficiency and safe hydrogen storage technology operating at ambient pressure and temperature. Currently, the basic idea behind electrochemical hydrogen storage is to store hydrogen in electrode materials. However, due to limitations in the reaction kinetics and chemical tolerance of hydrogen storage materials, the efficiency of current electrochemical hydrogen storage is too low to realize the aforementioned advantages. Summary of the Invention

[0005] The purpose of this invention is to use hydrogen peroxide as a hydrogen storage medium to improve the energy efficiency of hydrogen storage and release while making the hydrogen storage medium independent of the electrochemical hydrogen storage and release device, which facilitates the large-scale application of hydrogen storage and release and provides technical connection for renewable energy consumption and renewable energy peak shaving.

[0006] This invention provides a large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide, comprising a hydrogen storage module, a hydrogen peroxide storage module, a hydrogen release module, and an AC-DC conversion module;

[0007] The hydrogen storage module operates when hydrogen is introduced at the anode and air / oxygen is introduced at the cathode. The cathode of the hydrogen storage module can catalyze the generation of hydrogen peroxide and discharge the generated hydrogen peroxide to the hydrogen peroxide storage module.

[0008] The hydrogen release module is used to operate when hydrogen peroxide is transported from the hydrogen peroxide storage module to the anode of the hydrogen release module and connected to DC power. The anode of the hydrogen release module can catalyze the hydrogen peroxide to generate hydrogen protons, which are then conducted to the cathode to release hydrogen gas.

[0009] The AC-DC conversion module is used to convert the DC power generated by the hydrogen storage module into AC power that can be connected to the AC bus, or to convert the AC power from the AC bus into DC power that can be used for the operation of the hydrogen release module.

[0010] Preferably, both the hydrogen storage module and the hydrogen release module include an anode, a cathode, and an electrolyte membrane, wherein the electrolyte membrane is located between the anode and the cathode and serves as an electron barrier between the two electrodes and an ion conduction barrier.

[0011] The anode of the hydrogen storage module is connected to a hydrogen storage device; the cathode of the hydrogen storage module is connected to an air / oxygen storage device. The hydrogen storage module generates direct current when hydrogen and air / oxygen are input. The anode of the hydrogen storage module includes a hydrogen storage module anode catalyst layer, and the cathode of the hydrogen storage module includes a hydrogen storage module cathode catalyst layer. The hydrogen storage module cathode catalyst layer has a porous hydrophobic structure.

[0012] Preferably, the liquid inlet of the hydrogen release module anode is connected to the hydrogen peroxide storage module, and the hydrogen release module consumes DC power while introducing hydrogen peroxide; the gas-liquid outlet of the hydrogen release module anode is connected to the hydrogen peroxide storage module and the oxygen / air storage device via a gas-liquid separator; the gas outlet of the hydrogen release module cathode is connected to the hydrogen storage device; the anode of the hydrogen release module includes a hydrogen release module anode catalyst layer, and the cathode of the hydrogen release module includes a hydrogen release module cathode catalyst layer; the hydrogen release module anode catalyst layer has a porous hydrophilic structure.

[0013] Preferably, the slurry of the cathode catalyst layer of the hydrogen storage module includes a hydrogen storage module cathode catalyst, a binder, a hydrophobic additive, and an aqueous alcohol solution; the mass ratio of the hydrogen storage module catalyst: binder: hydrophobic additive is 1:0.4-1.2:0.02-0.2.

[0014] The mass ratio of alcohol to water in the alcohol-water solution is 1-5:0.1-5;

[0015] The cathode catalyst of the hydrogen storage module is any one of platinum-based, carbon-based, macrocyclic metal complex materials, transition metal oxides and their composite materials;

[0016] The binder is any one or a mixture of multiple of the following: perfluorosulfonic acid polyelectrolyte, quaternized polysulfone polyelectrolyte, polybenzimidazole polyelectrolyte, polyvinyl alcohol polyelectrolyte, and polytetrafluoroethylene;

[0017] The hydrophobic additive is any one or a mixture of multiple of the following: fluorosilane coupling agent, polytetrafluoroethylene, polyvinylidene fluoride hydrophobic amino acid, methacrylic acid coumarin, and hydroxyethyl coumarin.

[0018] The alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

[0019] Preferably, the slurry of the anode catalyst layer of the hydrogen release module includes the anode catalyst of the hydrogen release module, a binder, a hydrophilic additive, and an aqueous alcohol solution:

[0020] The anode catalyst of the hydrogen release module is any one of platinum-based, carbon-based, macrocyclic metal complex materials, transition metal oxides and their composite materials;

[0021] The binder is any one or a mixture of multiple of the following: perfluorosulfonic acid polyelectrolyte, quaternized polysulfone polyelectrolyte, polybenzimidazole polyelectrolyte, polyvinyl alcohol polyelectrolyte, and polytetrafluoroethylene;

[0022] The hydrophilic additive is any one or a mixture of multiple types of polyvinyl alcohol, carboxymethyl cellulose, hydrophilic aminopyridine, and aniline;

[0023] The alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol;

[0024] The mass ratio of the hydrogen release module anode catalyst: binder: hydrophilic additive is 1:0.4~1.2:0.02~0.2, and the mass ratio of alcohol:water in the alcohol-water solution is 1~5:0.1~4.

[0025] Preferably, the platinum-based material is any one or more combinations of platinum-mercury alloy, platinum alloy, and platinum-ruthenium alloy; the carbon-based material is a carbon material co-doped with metal and non-metal; and the macrocyclic metal complex material is any one of cobalt phthalocyanine, cobalt porphyrin, iron phthalocyanine, iron porphyrin, and Co-Salen.

[0026] Preferably, the catalyst in the cathode catalyst layer of the hydrogen storage module is a cobalt-oxygen-nitrogen co-hexaned carbon catalyst, and the hydrophobic additive is polytetrafluoroethylene; the catalyst in the anode catalyst layer of the hydrogen release module is pyrrole-axially coordinated cobalt phthalocyanine, and the hydrophilic agent is polyvinyl alcohol.

[0027] Preferably, the method for preparing the cathode catalyst layer of the hydrogen storage module is as follows: the cathode catalyst of the hydrogen storage module, binder, hydrophobic additive and alcohol aqueous solution are mixed and dispersed to form a uniform catalyst slurry; the catalyst slurry is sprayed or coated onto the carrier of the electrolyte membrane or catalyst layer to form a catalyst layer with a porous structure.

[0028] The solid content of the catalyst slurry is 2 wt.% to 15 wt.%.

[0029] The mass ratio of the catalyst to the binder is 1:0.4 to 1.2;

[0030] The hydrophobic additive is polytetrafluoroethylene or polyvinylidene fluoride;

[0031] The alcohol-water mass ratio is 1-5:0.1-4, and the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

[0032] Preferably, the preparation method of the anode catalyst layer of the hydrogen release module is as follows: the catalyst, binder, hydrophilic additive and alcohol aqueous solution are mixed and dispersed to form a uniform catalyst slurry; the catalyst slurry is sprayed or coated onto the electrolyte membrane or the carrier of the catalyst layer to form a catalyst layer with a porous structure.

[0033] The solid content of the catalyst slurry is 2 wt.% to 15 wt.%.

[0034] The mass ratio of the catalyst to the binder is 1:0.4 to 1.2;

[0035] The hydrophilic additives are polyvinyl alcohol, carboxymethyl cellulose, hydrophilic aminopyridine, and aniline;

[0036] The alcohol-to-water mass ratio is 1-5:0.1-4, and the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

[0037] Preferably, specifically as follows:

[0038] Construct a large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 1;

[0039] During hydrogen storage, oxygen or air is introduced into the cathode of the hydrogen storage module, and hydrogen is introduced into the anode of the hydrogen storage module at a flow rate of 0.05 L / min to 1.00 L / min; a load is connected; at the gas / liquid outlet of the cathode of the hydrogen storage module, hydrogen peroxide is transferred to the hydrogen peroxide storage module through a gas-liquid separator.

[0040] During hydrogen release, a voltage of 0.7V to 1.0V is applied to the anode and cathode of the hydrogen release module; hydrogen peroxide is transported to the anode of the hydrogen release module through the hydrogen peroxide storage module; the hydrogen generated at the cathode of the hydrogen release module can be used directly or stored for later use.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] The electrochemical hydrogen storage and release method provided by this invention utilizes hydrogen peroxide, which has a high activation energy barrier, a high static safety factor, and a hydrogen storage density of 2.9 wt%, as a hydrogen storage medium. It can achieve large-scale hydrogen storage for a long time under normal temperature and pressure. Hydrogen peroxide as a hydrogen storage medium can be used independently of the hydrogen storage and release device without the constraints of scale-up. The hydrogen storage medium and key materials in this invention are not resource-dependent and are inexpensive, which is conducive to large-scale hydrogen storage.

[0043] The electrochemical hydrogen storage and release system provided by this invention complements and couples the electrical energy input and output accompanying the hydrogen storage and release process with the renewable energy grid to "shave peaks and fill valleys," connecting and integrating hydrogen energy with multi-energy systems to improve system energy efficiency.

[0044] The cathode catalyst layer of the hydrogen storage module of the present invention is optimized to a porous hydrophobic structure, and the anode catalyst layer of the hydrogen release module is optimized to a porous hydrophilic structure.

[0045] Simultaneously, during the formation of the porous hydrophobic structure, this invention constructs a highly efficient three-phase reaction interface by regulating the distribution of binders and hydrophobic agents on the catalyst surface, accelerating the discharge of generated hydrogen peroxide. Simultaneously, by cross-linking catalyst particles and adjusting the pore structure ratio, it constructs a highly efficient gas-liquid transport channel, accelerating the mass transfer and discharge of hydrogen peroxide and reducing its accumulation and self-decomposition. During the formation of the porous hydrophilic structure, by regulating the distribution of binders and hydrophilic agents on the catalyst surface, a highly efficient three-phase reaction interface is constructed, improving the utilization rate of hydrogen peroxide reaction. Simultaneously, by cross-linking catalyst particles and adjusting the pore structure ratio, it constructs a highly efficient gas-liquid transport channel, accelerating the mass transfer and diffusion of hydrogen peroxide to the reaction interface. Through the combined effect of the porous hydrophobic and porous hydrophilic structures, the efficient generation and decomposition of hydrogen peroxide are achieved, promoting a more efficient and stable hydrogen production-storage-hydrogen power generation process.

[0046] The hydrogen storage and release process of this invention involves 2e - The hydrogen storage and release process is characterized by fast transfer, fast kinetic response, low overpotential, high reversibility, and high energy efficiency. Based on the optimization and improvement of the catalyst layer, this invention enables stable electrical energy input and output throughout the entire hydrogen storage and release process, making the electrical energy output of the entire hydrogen storage and release system more stable. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of an electrochemical hydrogen peroxide storage and release device provided in Embodiment 1 of the present invention.

[0048] Figure 2 This is a schematic diagram of the assembly of each component in the hydrogen storage and release module in Embodiment 1 of the present invention.

[0049] Figure 3The following are the hydrogen storage and release data for Example 1. (a) Discharge voltage-Faraday efficiency-hydrogen peroxide generation rate graph when the hydrogen storage module is working; (b) Working voltage-Faraday efficiency-hydrogen generation rate graph when the hydrogen release module is working.

[0050] Figure 4 This is a graph showing hydrogen storage data from Example 2. Figure 4 (a) shows the structure of the porous hydrophobic catalyst layer at the cathode of the hydrogen storage module. Figure 4 (b) When the hydrogen storage module is working, at a discharge voltage of 0.6V, the data graph of the mass ratio of mbutanol to mwater, the Faraday efficiency, and the hydrogen peroxide generation rate during the preparation of the cathode catalyst layer; (b) When the hydrogen release module is working, at an applied voltage of 0.85V, the data graph of the mass ratio of mcatalyst to mbinder to mpolyvinyl alcohol, the Faraday efficiency, and the hydrogen generation rate during the preparation of the anode catalyst layer.

[0051] Figure 5 This is a graph showing the hydrogen release data for Example 2. Figure 5 (a) shows the structure of the porous hydrophilic catalyst layer at the anode of the hydrogen release module; Figure 5 (b) When the hydrogen release module is working, with an applied voltage of 0.85V, the anode catalyst layer preparation process m catalyst:m binder:m polyvinyl alcohol mass ratio - Faraday efficiency / hydrogen generation rate data graph.

[0052] Explanation of reference numerals in the attached figures:

[0053] 1. Hydrogen storage module, 2. Hydrogen peroxide storage module, 3. Hydrogen release module. Detailed Implementation

[0054] The following is in conjunction with the appendix Figure 1-5 The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. 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.

[0055] To address the aforementioned demand for electrochemical hydrogen storage, the inventors have developed a novel high-efficiency, large-scale electrochemical hydrogen storage and release technology using hydrogen peroxide as an inorganic liquid hydrogen storage medium. During the electrochemical hydrogen storage process, the two-electron oxygen reduction reaction (2e...) is utilized. - ORR,O2+2H + +2e - →H2O2,E 0 =0.695V) to generate hydrogen peroxide; during the dehydrogenation process, the anodic electrochemical H2O2 oxidation reaction (HPOR, H2O2→O2+2H) is utilized. + +2e - E 0 =0.695V).

[0056] To realize the advantages of electrochemical hydrogen storage, the following key requirements need to be met: (1) The hydrogen storage medium must be independent of the hydrogen storage and release device and have no restrictions on scale-up; (2) The hydrogen storage medium and key materials have no resource dependence; (3) The hydrogen storage density is not less than 2 wt%.

[0057] The electrochemical hydrogen storage and release system and method provided by this invention utilizes hydrogen peroxide, which has a high activation energy barrier, a high static safety factor, and a hydrogen storage density of 2.9 wt%, as a hydrogen storage medium. It can achieve large-scale hydrogen storage for a long time under normal temperature and pressure. Hydrogen peroxide as a hydrogen storage medium can be used independently of the hydrogen storage and release device without the constraints of scale-up. The hydrogen storage medium and key materials in this invention are not resource-dependent and are inexpensive, which is conducive to large-scale hydrogen storage.

[0058] The present invention provides a large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide, comprising a hydrogen storage module 1, a hydrogen peroxide storage module 2, a hydrogen release module 3, and an AC-DC conversion module;

[0059] Hydrogen storage module 1 is used to operate when hydrogen is input at the anode and air / oxygen is input at the cathode. The cathode of hydrogen storage module 1 can catalyze the generation of hydrogen peroxide and discharge the generated hydrogen peroxide to hydrogen peroxide storage module 2.

[0060] The hydrogen release module 3 is used to operate when the hydrogen peroxide storage module 2 transports hydrogen peroxide to the anode of the hydrogen release module 3 and is connected to DC power. The anode of the hydrogen release module 3 can catalyze the hydrogen peroxide to generate hydrogen protons, which are then conducted to the cathode to release hydrogen gas.

[0061] The AC-DC conversion module is used to convert the DC power generated by the hydrogen storage module 1 into AC power that can be connected to the AC bus, or to convert the AC power of the AC bus into DC power that can be used for the operation of the hydrogen release module 3.

[0062] Based on the above content disclosed in this embodiment, in order to construct a large-scale, high-efficiency electrochemical hydrogen storage and release system, the hydrogen storage module 2 and the hydrogen release module 3 of this embodiment can be regarded as a set of independent single-cell components. A large number of identical single cells can be used to form a stack. For example, multiple hydrogen storage modules and multiple hydrogen release modules of this embodiment can be stacked at the same time. In the stacked structure, each hydrogen storage module and hydrogen release module can work normally and independently, and the combined effect can achieve a larger-scale hydrogen storage or hydrogen release.

[0063] Preferably, both the hydrogen storage module 1 and the hydrogen release module 3 include an anode, a cathode, and an electrolyte membrane, wherein the electrolyte membrane is located between the anode and the cathode and is used for electron blocking and ion conduction between the two electrodes;

[0064] The anode of the hydrogen storage module 1 is connected to a hydrogen storage device; the cathode of the hydrogen storage module 1 is connected to an air / oxygen storage device. The hydrogen storage module 1 generates direct current when hydrogen and air / oxygen are input. The anode of the hydrogen storage module 1 includes a hydrogen storage module anode catalyst layer, and the cathode of the hydrogen storage module 1 includes a hydrogen storage module cathode catalyst layer. The hydrogen storage module cathode catalyst layer has a porous hydrophobic structure.

[0065] Preferably, the liquid inlet of the anode of the hydrogen release module 3 is connected to the hydrogen peroxide storage module 2, and the hydrogen release module 3 consumes DC power while introducing hydrogen peroxide; the gas-liquid outlet of the anode of the hydrogen release module 3 is connected to the hydrogen peroxide storage module 2 and the oxygen / air storage device via a gas-liquid separator; the gas outlet of the cathode of the hydrogen release module 3 is connected to the hydrogen storage device; the anode of the hydrogen release module 3 includes a hydrogen release module anode catalyst layer, and the cathode of the hydrogen release module 3 includes a hydrogen release module cathode catalyst layer; the hydrogen release module anode catalyst layer has a porous hydrophilic structure.

[0066] Preferably, the slurry of the cathode catalyst layer of the hydrogen storage module includes the cathode catalyst of the hydrogen storage module, a binder, a hydrophobic additive, and an aqueous alcohol solution; the mass ratio of the hydrogen storage module catalyst: binder: hydrophobic additive is 1:0.4~1.2:0.02~0.2.

[0067] The mass ratio of alcohol to water in the alcohol-water solution is 1-5:0.1-5;

[0068] The cathode catalyst of the hydrogen storage module is any one of platinum-based, carbon-based, macrocyclic metal complex materials, transition metal oxides and their composite materials;

[0069] The binder is any one or a mixture of multiple of the following: perfluorosulfonic acid polyelectrolyte, quaternized polysulfone polyelectrolyte, polybenzimidazole polyelectrolyte, polyvinyl alcohol polyelectrolyte, and polytetrafluoroethylene;

[0070] The hydrophobic additive is any one or a mixture of multiple of the following: fluorosilane coupling agent, polytetrafluoroethylene, polyvinylidene fluoride hydrophobic amino acid, methacrylic acid coumarin, and hydroxyethyl coumarin.

[0071] The alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

[0072] Preferably, the slurry of the anode catalyst layer of the hydrogen release module 3 includes the hydrogen release module anode catalyst, binder, hydrophilic additive, and alcohol-water solution:

[0073] The anode catalyst of the hydrogen release module is any one of platinum-based, carbon-based, macrocyclic metal complex materials, transition metal oxides and their composite materials;

[0074] The binder is any one or a mixture of multiple of the following: perfluorosulfonic acid polyelectrolyte, quaternized polysulfone polyelectrolyte, polybenzimidazole polyelectrolyte, polyvinyl alcohol polyelectrolyte, and polytetrafluoroethylene;

[0075] The hydrophilic additive is any one or a mixture of multiple types of polyvinyl alcohol, carboxymethyl cellulose, hydrophilic aminopyridine, and aniline;

[0076] The alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol;

[0077] The mass ratio of the hydrogen release module anode catalyst: binder: hydrophilic additive is 1:0.4~1.2:0.02~0.2, and the mass ratio of alcohol:water in the alcohol-water solution is 1~5:0.1~4.

[0078] Preferably, the platinum-based material in the anode catalyst is any one or more combinations of platinum-mercury alloy, platinum-gold alloy, and platinum-ruthenium alloy; the carbon-based material is a carbon material co-doped with metal and non-metal; and the macrocyclic metal complex material is any one of cobalt phthalocyanine, cobalt porphyrin, iron phthalocyanine, iron porphyrin, and Co-Salen.

[0079] Preferably, the catalyst in the cathode catalyst layer of the hydrogen storage module 1 is a cobalt-oxygen-nitrogen co-hexaned carbon catalyst, and the hydrophobic additive is polytetrafluoroethylene. The catalyst in the anode catalyst layer of the hydrogen release module 3 is pyrrole-axially coordinated cobalt phthalocyanine, and the hydrophilic agent is polyvinyl alcohol.

[0080] Preferably, the method for preparing the cathode catalyst layer of the hydrogen storage module 1 is as follows: the cathode catalyst of the hydrogen storage module, binder, hydrophobic additive and alcohol aqueous solution are mixed and dispersed to form a uniform catalyst slurry; the catalyst slurry is sprayed or coated onto the carrier of the electrolyte membrane or catalyst layer to form a catalyst layer with a porous structure.

[0081] The solid content of the catalyst slurry is 2 wt.% to 15 wt.%.

[0082] The mass ratio of the catalyst to the binder is 1:0.4 to 1.2;

[0083] The hydrophobic additive is polytetrafluoroethylene or polyvinylidene fluoride;

[0084] The alcohol-water mass ratio is 1-5:0.1-4, and the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

[0085] This preparation method utilizes the solvent effect of binders and hydrophobic agents to adjust the distribution of binders and hydrophobic agents on the catalyst surface, constructs a highly efficient three-phase reaction interface, accelerates the discharge of generated hydrogen peroxide, and reduces the self-decomposition of hydrogen peroxide.

[0086] This preparation method utilizes the solvent effect of binders and hydrophobic agents to crosslink catalyst particles, adjust the pore structure ratio, construct an efficient gas-liquid transport channel, accelerate the mass transfer and discharge of hydrogen peroxide, and reduce the accumulation and self-decomposition of hydrogen peroxide.

[0087] Preferably, the preparation method of the anode catalyst layer of the hydrogen release module 2 is as follows: the catalyst, binder, hydrophilic additive and alcohol aqueous solution are mixed and dispersed to form a uniform catalyst slurry; the catalyst slurry is sprayed or coated onto the electrolyte membrane or the carrier of the catalyst layer to form a catalyst layer with a porous structure.

[0088] The solid content of the catalyst slurry is 2 wt.% to 15 wt.%.

[0089] The mass ratio of the catalyst to the binder is 1:0.4 to 1.2;

[0090] The hydrophilic additives are polyvinyl alcohol, carboxymethyl cellulose, hydrophilic aminopyridine, and aniline;

[0091] The alcohol-water mass ratio is 1-5:0.1-4, and the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

[0092] This preparation method utilizes the solvent effect of binders and hydrophilic agents to adjust the distribution of binders and hydrophilic agents on the catalyst surface, constructs a highly efficient three-phase reaction interface, improves the utilization rate of hydrogen peroxide reaction, and accelerates hydrogen emission.

[0093] This preparation method utilizes the solvent effect of binders and hydrophilic agents to crosslink catalyst particles, adjust the pore structure ratio, construct an efficient gas-liquid transport channel, accelerate the mass transfer and discharge of hydrogen peroxide, and reduce the accumulation and self-decomposition of hydrogen peroxide.

[0094] Preferably, the method for storing and releasing hydrogen in a large-scale, high-efficiency electrochemical hydrogen storage and release system is as follows:

[0095] Establish a large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide;

[0096] During hydrogen storage, oxygen or air is introduced into the cathode of hydrogen storage module 1, and hydrogen is introduced into the anode of hydrogen storage module 1 at a flow rate of 0.05 L / min to 1.00 L / min; a load is connected; at the gas / liquid outlet of the cathode of hydrogen storage module 1, hydrogen peroxide is transferred to the hydrogen peroxide storage module via a gas-liquid separator; during hydrogen release, a voltage of 0.7V to 1.0V is applied to the anode and cathode of hydrogen release module 3; hydrogen peroxide is transported to the anode of hydrogen release module 3 through the hydrogen peroxide storage module; the hydrogen generated at the cathode of hydrogen release module 3 can be used directly or stored for later use.

[0097] Example 1

[0098] Please see Figure 1 This is a schematic diagram of the electrochemical hydrogen peroxide storage and release device used in Embodiment 1 of the present invention. The hydrogen storage and release system includes a hydrogen storage module, a hydrogen release module, a hydrogen peroxide storage module, an AC / DC device, a DC / AC device, a circuit breaker, and a transformer.

[0099] The hydrogen storage module 1 includes a hydrogen storage module anode, a hydrogen storage module cathode, a hydrogen storage module electrolyte membrane, a gas-liquid separator, a small hydrogen storage device, and an air / oxygen storage device. The hydrogen storage module anode includes an inlet, an outlet, a flow channel plate, a gas diffusion layer, and an electrode catalyst layer. The inlet and outlet are connected to the small hydrogen storage device. The hydrogen storage module cathode includes an inlet, a gas / liquid outlet, a flow channel plate, a gas / liquid diffusion layer, and an electrode catalyst layer. The inlet is connected to the oxygen / air storage device. The gas / liquid outlet is connected to the hydrogen peroxide storage module and the oxygen / air storage device through the gas-liquid separator. The hydrogen storage module operates when hydrogen and air / oxygen are input, and the generated direct current is connected to the AC bus through a DC device, a DC / AC device, a circuit breaker, and a transformer. The hydrogen peroxide generated at the cathode is stored in the hydrogen peroxide storage module 2.

[0100] The hydrogen release module 3 includes a hydrogen release module anode, a hydrogen release module cathode, a hydrogen release module electrolyte membrane, a gas-liquid separator, a small hydrogen storage device, and an air / oxygen storage device. The hydrogen release module anode includes a liquid inlet, a gas / liquid outlet, a flow channel plate, a gas / liquid diffusion layer, and an electrode catalyst layer. The liquid inlet is connected to the hydrogen peroxide storage module. The gas / liquid outlet is connected to the hydrogen peroxide storage module 2 and the oxygen / air storage device via the gas-liquid separator. The hydrogen release module cathode includes a gas outlet, a flow channel plate, a gas diffusion layer, and an electrode catalyst layer. The gas outlet is connected to the small hydrogen storage device for timely hydrogen use. The hydrogen release system consumes direct current (DC) power while introducing hydrogen peroxide. The DC power can be provided through a DC device, an AC / DC device, a circuit breaker, a transformer, and an AC bus.

[0101] This novel hydrogen storage technology, based on an electrochemical hydrogen peroxide storage and release system, boasts low system cost, low operating energy consumption, flexible operation, and rapid hydrogen storage and release response. Its hydrogen storage and release process is accompanied by electrical energy input and output, allowing for complementary coupling with renewable energy grids to "shaving peaks and filling valleys," and seamlessly integrating hydrogen energy with multi-energy systems to improve system energy efficiency. The system can be deployed on a large scale, either centrally or in a decentralized manner. The hydrogen storage and release process can be carried out efficiently at ambient temperature and pressure. Hydrogen peroxide, as the storage medium, can be safely and statically stored on a large scale over long periods, with a hydrogen storage density greater than 2.9 wt%. The key materials of the hydrogen storage and release system are not resource-dependent.

[0102] Please see Figure 2This is a schematic diagram of the assembly of each component in the hydrogen storage and release module of Embodiment 1 of the present invention. In both the hydrogen storage and release modules, the diffusion layers of both the anode and cathode are carbon paper; the flow channels of both the anode and cathode are graphite plates; the binders of both the anode and cathode are commercial perfluorosulfonic acid resin (Nafion, 5wt% dispersion); the electrolyte membrane is a commercial proton exchange membrane, Nafion N-211; and the sealing ring is a fiber-reinforced polytetrafluoroethylene membrane. In the hydrogen storage module, the cathode uses a cobalt-oxygen-nitrogen co-doped carbon catalyst to prepare the catalyst layer, and the anode uses a Pt / C catalyst to prepare the catalyst layer. In the hydrogen release module, the anode uses a pyrrole-axially coordinated cobalt phthalocyanine catalyst to prepare the catalyst layer, and the cathode uses a Pt / C catalyst to prepare the catalyst layer. The assembly steps of the above hydrogen storage and release device are as follows:

[0103] (1) Preparation of cathode catalyst layer for hydrogen storage module: Cobalt-oxygen-nitrogen co-hexaned carbon catalyst, binder, and hydrophobic additive were dispersed in a mixture of isopropanol and deionized water at a mass ratio of 1:1:0.05, wherein the mass ratio of alcohol to water was 2:2 and the solid content was 2 wt.%. The mixture was sprayed evenly onto a 5 cm thick surface. 2 Carbon paper, loading 2 mg / cm³ 2 ;

[0104] (2) Preparation of the anode catalyst layer for the hydrogen storage module: A commercial 20wt% Pt / C catalyst and a binder were dispersed in a mixture of n-propanol and deionized water at a mass ratio of 7:3, wherein the mass ratio of alcohol to water was 2:2 and the solid content was 2wt.%; the mixed dispersion was sprayed onto a 5cm thick surface. 2 The loading on the carbon paper layer is 0.05 mg / cm³. 2 ;

[0105] (3) Preparation of the anode catalyst layer for the hydrogen release module: The binder, pyrrole-coordinated axially coordinated cobalt phthalocyanine catalyst, and hydrophilic additive are dispersed in a mixture of ethanol and deionized water at a mass ratio of 1:0.8:0.05, wherein the mass ratio of ethanol to water is 2:2 and the solid content is 2wt.%; the mixed dispersion is sprayed evenly onto a 5cm layer. 2 Carbon paper, loading 2 mg / cm³ 2 ;

[0106] (4) Preparation of the cathode catalyst layer for the hydrogen release module: A commercial 20wt% Pt / C catalyst and a binder were dispersed in a mixture of n-butanol and deionized water at a mass ratio of 7:3, wherein the mass ratio of alcohol to water was 2:2 and the solid content was 2wt.%; the mixed dispersion was sprayed onto a 5cm thick surface. 2 The loading on the carbon paper diffusion layer is 0.05 mg / cm³. 2 ;

[0107] (5) Hydrogen storage and release module assembly: Assemble the two modules' electrode catalyst layers, proton exchange membranes, and related fixtures, such as... Figure 2 .

[0108] (6) Hydrogen storage and release performance tests are as follows:

[0109] During operation of the storage and release module, oxygen and hydrogen are introduced into the anode and cathode respectively at a gas flow rate of 0.5 L / min and an operating temperature of 25°C. Hydrogen is stored at constant pressure using a fuel cell workstation (Scribner 850e) at voltages of 0.6V, 0.5V, 0.4V, and 0.25V. The hydrogen storage efficiency is calculated by titrating hydrogen peroxide with potassium permanganate solution. During operation of the hydrogen release module, hydrogen peroxide is pumped into the anode through a hydrogen peroxide storage tank. The generated hydrogen is collected by applying different potentials (0.8V, 0.85V, 0.9V, and 1.0V) to the electrodes, and the hydrogen release efficiency is calculated.

[0110] Figure 3 (a) Graph showing discharge voltage, Faraday efficiency, and hydrogen peroxide generation rate when the hydrogen storage module is operating; (b) Graph showing operating voltage, Faraday efficiency, and hydrogen generation rate when the hydrogen release module is operating. As the discharge voltage decreases, the hydrogen peroxide generation rate gradually increases, reaching 300 μmol / cm³ near 0.25V. 2 / h.

[0111] Figure 3 (b) The graph shows the operating voltage, Faraday efficiency, and hydrogen generation rate when the hydrogen release module is in operation. As the applied voltage increases, the hydrogen generation rate gradually increases, reaching 25 mmol / cm² near 1.0V. 2 / h.

[0112] Example 2

[0113] The hydrogen storage and release module in this embodiment is basically the same as that in Embodiment 1, except that: in the hydrogen storage module, the cathode utilizes an alcohol-water ratio to construct a porous hydrophobic catalyst layer structure; in the hydrogen release module, the anode uses a hydrophilic additive to construct a porous hydrophilic catalyst layer structure. The slurry preparation conditions for both catalyst layers are as follows:

[0114] Table 1. Slurry ratio of cathode catalyst layer in hydrogen storage module

[0115]

[0116] Table 2. Anode catalyst layer slurry ratio in hydrogen release module

[0117]

[0118]

[0119] Figure 4 (a) Hydrogen storage module, cathode porous hydrophobic catalyst layer structure.

[0120] Figure 4 (b) Graph showing the mass ratio of butanol to water and the Faraday efficiency / hydrogen peroxide generation rate during the cathode catalyst layer preparation process at a discharge voltage of 0.6V when the hydrogen storage module is operating. As the mass ratio of butanol to water decreases, the hydrogen peroxide generation rate gradually increases, reaching 320 μmol / cm³ when the mass ratio of butanol to water is 2:2. 2 / h.

[0121] Figure 5 (a) Hydrogen release module, with a porous hydrophilic catalyst layer structure at the anode.

[0122] Figure 5 (b) When the hydrogen release module is operating and an external voltage of 0.85V is applied, the graph shows the Faraday efficiency / hydrogen generation rate data for the anode catalyst layer preparation process with the mass ratio of mcatalyst:m binder:mpolyvinyl alcohol. As the mass ratio of mcatalyst:m binder:mpolyvinyl alcohol increases, the hydrogen generation rate gradually increases. The highest Faraday efficiency, reaching 99%, is achieved when the mass ratio of mcatalyst:m binder:mpolyvinyl alcohol is 1:1:0.2.

[0123] In a hydrogen storage and release system, the convective transport of hydrogen peroxide determines the rate of hydrogen storage and release. Constructing a porous catalyst layer structure and establishing a long-term effective three-phase reaction interface are key to achieving efficient transport of the hydrogen storage medium within the electrode. In this embodiment, in the hydrogen storage module, the hydrophobic structure of the macroporous structure of the cathode catalyst layer facilitates the rapid removal of hydrogen peroxide, which is beneficial for hydrogen storage; in the hydrogen release module, the hydrophilic structure of the anode facilitates the oxidation reaction of hydrogen peroxide, which is beneficial for hydrogen release.

[0124] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide, characterized in that, It includes a hydrogen storage module (1), a hydrogen peroxide storage module (2), a hydrogen release module (3), and an AC-DC conversion module; The hydrogen storage module (1) is used to operate when hydrogen is input at the anode and air / oxygen is input at the cathode. The cathode of the hydrogen storage module (1) can catalyze the generation of hydrogen peroxide and generate direct current at the same time; and discharge the generated hydrogen peroxide to the hydrogen peroxide storage module (2). The hydrogen release module (3) is used to transport hydrogen peroxide from the hydrogen peroxide storage module (2) to the anode of the hydrogen release module (3) and to operate when connected to DC power. The anode of the hydrogen release module (3) can catalyze the hydrogen peroxide to generate hydrogen protons, and the hydrogen protons are conducted to the cathode to release hydrogen gas. Both the hydrogen storage module (1) and the hydrogen release module (3) include an anode, a cathode and an electrolyte membrane. The electrolyte membrane is located between the anode and the cathode and is used for electron blocking and ion conduction between the two electrodes. The anode of the hydrogen storage module (1) includes a hydrogen storage module anode catalyst layer, and the cathode of the hydrogen storage module (1) includes a hydrogen storage module cathode catalyst layer. The hydrogen storage module cathode catalyst layer has a porous hydrophobic structure. The anode of the hydrogen release module (3) includes a hydrogen release module anode catalyst layer, and the cathode of the hydrogen release module (3) includes a hydrogen release module cathode catalyst layer. The hydrogen release module anode catalyst layer has a porous hydrophilic structure. The slurry for the cathode catalyst layer of the hydrogen storage module includes a hydrogen storage module cathode catalyst, a binder, a hydrophobic additive, and an aqueous alcohol solution; the mass ratio of the hydrogen storage module cathode catalyst: binder: hydrophobic additive is 1: 0.4-1.2: 0.02-0.2; the mass ratio of alcohol to water in the aqueous alcohol solution is 1-5: 0.1-5; the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol; The slurry of the anode catalyst layer of the hydrogen release module (3) includes the hydrogen release module anode catalyst, binder, hydrophilic additive and alcohol-water solution: the alcohol is one or more of anhydrous ethanol, n-propanol, isopropanol and n-butanol; the mass ratio of hydrogen release module anode catalyst: binder: hydrophilic additive is 1:0.4~1.2:0.02~0.2, and the mass ratio of alcohol:water in the alcohol-water solution is 1~5:0.1~4; The AC-DC conversion module is used to convert the DC power generated by the hydrogen storage module (1) into AC power that can be connected to the AC bus, or to convert the AC power of the AC bus into DC power that can be used for the operation of the hydrogen release module (3).

2. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 1, characterized in that, The anode of the hydrogen storage module (1) is connected to a hydrogen storage device; the cathode of the hydrogen storage module (1) is connected to an air / oxygen storage device, and the hydrogen storage module (1) generates direct current when hydrogen and air / oxygen are input.

3. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 2, characterized in that, The inlet of the anode of the hydrogen release module (3) is connected to the hydrogen peroxide storage module (2), and the hydrogen release module (3) consumes DC power while introducing hydrogen peroxide; the gas-liquid outlet of the anode of the hydrogen release module (3) is connected to the hydrogen peroxide storage module (2) and the oxygen / air storage device via a gas-liquid separator; the outlet of the cathode of the hydrogen release module (3) is connected to the hydrogen storage device.

4. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 2, characterized in that, The cathode catalyst of the hydrogen storage module is any one of platinum-based, carbon-based, macrocyclic metal complex materials, transition metal oxides and their composite materials; The binder is any one or a mixture of multiple of the following: perfluorosulfonic acid polyelectrolyte, quaternized polysulfone polyelectrolyte, polybenzimidazole polyelectrolyte, polyvinyl alcohol polyelectrolyte, and polytetrafluoroethylene; The hydrophobic additive is any one or a mixture of multiple of the following: fluorosilane coupling agent, polytetrafluoroethylene, polyvinylidene fluoride hydrophobic amino acid, methacrylic acid coumarin, and hydroxyethyl coumarin.

5. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 3, characterized in that, The anode catalyst of the hydrogen release module is any one of platinum-based, carbon-based, macrocyclic metal complex materials, transition metal oxides and their composite materials; The binder is any one or a mixture of multiple of the following: perfluorosulfonic acid polyelectrolyte, quaternized polysulfone polyelectrolyte, polybenzimidazole polyelectrolyte, polyvinyl alcohol polyelectrolyte, and polytetrafluoroethylene; The hydrophilic additive is any one or a mixture of multiple of polyvinyl alcohol, carboxymethyl cellulose, hydrophilic aminopyridine, and aniline.

6. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 4 or 5, characterized in that, The platinum-based material is any one or more combinations of platinum-mercury alloy, platinum alloy, and platinum-ruthenium alloy; the carbon-based material is a carbon material co-doped with metal and non-metal; the macrocyclic metal complex material is any one of cobalt phthalocyanine, cobalt porphyrin, iron phthalocyanine, iron porphyrin, and Co-Salen.

7. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 4 or 5, characterized in that, The catalyst in the cathode catalyst layer of the hydrogen storage module (1) is a cobalt-oxygen-nitrogen co-hexaned carbon catalyst, and the hydrophobic additive is polytetrafluoroethylene; the catalyst in the anode catalyst layer of the hydrogen release module (3) is pyrrole-axially coordinated cobalt phthalocyanine, and the hydrophilic agent is polyvinyl alcohol.

8. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 2, characterized in that, The specific preparation method of the cathode catalyst layer of the hydrogen storage module (1) is as follows: the cathode catalyst of the hydrogen storage module, binder, hydrophobic additive and alcohol aqueous solution are mixed and dispersed to form a uniform catalyst slurry; the catalyst slurry is sprayed or scraped onto the carrier of the electrolyte membrane or catalyst layer to form a catalyst layer with a porous structure. The solid content of the catalyst slurry is 2 wt.% to 15 wt.%. The mass ratio of the cathode catalyst to the binder in the hydrogen storage module is 1:0.4 to 1.2; The hydrophobic additive is polytetrafluoroethylene or polyvinylidene fluoride; The alcohol-water mass ratio is 1-5:0.1-4, and the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

9. The large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 2, characterized in that, The specific preparation method of the anode catalyst layer of the hydrogen release module (3) is as follows: the anode catalyst of the hydrogen release module, binder, hydrophilic additive and alcohol aqueous solution are mixed and dispersed to form a uniform catalyst slurry; the catalyst slurry is sprayed or scraped onto the carrier of the electrolyte membrane or catalyst layer to form a catalyst layer with a porous structure. The solid content of the catalyst slurry is 2 wt.% to 15 wt.%. The mass ratio of catalyst to binder in the hydrogen release module is 1:0.4 to 1.2; The hydrophilic additives are polyvinyl alcohol, carboxymethyl cellulose, hydrophilic aminopyridine, and aniline; The alcohol-water mass ratio is 1-5:0.1-4, and the alcohol is one or a mixture of two or more of anhydrous ethanol, n-propanol, isopropanol, and n-butanol.

10. The method for storing and releasing hydrogen in a large-scale, high-efficiency electrochemical hydrogen storage and release system as described in claim 1, characterized in that, Specifically as follows: Construct a large-scale, high-efficiency electrochemical hydrogen storage and release system for hydrogen peroxide as described in claim 1; During hydrogen storage, oxygen or air is introduced into the cathode of the hydrogen storage module (1), and hydrogen is introduced into the anode of the hydrogen storage module (1) at a flow rate of 0.05 L / min to 1.00 L / min; a load is connected; at the gas / liquid outlet of the cathode of the hydrogen storage module (1), hydrogen peroxide is transferred to the hydrogen peroxide storage module through a gas-liquid separator. During hydrogen release, a voltage of 0.7 V to 1.0 V is applied to the anode and cathode of the hydrogen release module (3); hydrogen peroxide is transported to the anode of the hydrogen release module (3) through the hydrogen peroxide storage module; the hydrogen generated at the cathode of the hydrogen release module (3) can be used directly or stored for later use.

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