Method for producing hydrogen molecules by energy radiation

Abstract

The present invention relates to a method for producing hydrogen by energy radiation, comprising: contacting a composite catalyst with at least one hydrogen-containing source, and energy radiating the composite catalyst and the hydrogen-containing source to produce hydrogen molecules, wherein the composite catalyst comprises at least one nano-substrate structure and at least one atomic site, the atomic site comprising one or more than two chemical elements of Ru, Rh, Ag, Au, Pt, Pd, Os, Ir.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for hydrogen production by energy radiation catalysis, in particular to a composite catalyst and its application in hydrogen production by energy radiation catalysis. BACKGROUND

[0002] In the field of new energy, hydrogen energy has been universally recognized as the most ideal and pollution-free green energy in the new century, because the only product of hydrogen combustion is water. Hydrogen is the most abundant element in nature, widely exists in water, fossil fuels and various carbohydrates. Hydrogen is also a major industrial raw material, and is the most important industrial gas and special gas, which is used as an important raw material for synthesizing ammonia, methanol and hydrochloric acid, and is also used as a reducing agent for metallurgy, a hydrogenation desulfurization agent for petroleum refining, etc.

[0003] However, the traditional hydrogen production method consumes a large amount of conventional energy, making the cost of hydrogen energy too high, which greatly limits the popularization and application of hydrogen energy. Therefore, scientists think of using inexhaustible and cheap solar energy as a primary energy in the process of hydrogen energy formation, which makes hydrogen energy development have a more broad prospect. Scientists have found that using photocatalytic materials as "media", solar energy can be used to split water into oxygen and hydrogen necessary for fuel cells. Scientists call this technology of producing hydrogen and oxygen only with sunlight and water as "one of the ideal technologies for human beings".

[0004] Due to the plasmonic effect, plasmonic metal catalysts can achieve a great enhancement of local energy on the surface of nanostructures. Thus, under the condition of mild overall reaction, the catalytic reaction is efficiently promoted, making it possible to achieve reactions that cannot be achieved at room temperature and pressure. In recent years, water has been decomposed into hydrogen and oxygen, but so far, more efficient, more stable and cost-effective catalysts still need to be developed.

[0005] The concept of single-atom catalysis has attracted widespread attention and research since it was proposed in recent years. With the development of advanced characterization techniques, single-atom catalysts provide the possibility of elucidating the structure-activity relationship of catalysts from the atomic and molecular level, and connecting heterogeneous catalysis and homogeneous catalysis. Single-atom catalysts have special structures, and thus exhibit different activity, selectivity and stability from conventional nano-catalysts.

[0006] Therefore, by combining the advantages of plasmonic effect and single-atom catalysis, it is possible to develop a hydrogen production catalyst that meets the commercial requirements in terms of efficiency, stability and cost. SUMMARY

[0007] Based on the technical problems existing in the background art, the present application illustrates a new type of plasmonic catalysis technology, the plasmonic catalyst includes atomic sites, such as single atomic sites and / or atomic clusters containing 2-25 atoms, and provides a unique method for preparing hydrogen in the presence of a cost-effective catalyst by decomposing a hydrogen-containing source, preferably water, through light radiation and / or thermal radiation.

[0008] An aspect of the present application is a method for producing hydrogen by energy radiation, comprising:

[0009] contacting a composite catalyst with at least one hydrogen-containing source, and

[0010] radiating energy to the composite catalyst and the hydrogen-containing source to produce hydrogen molecules, wherein

[0011] the composite catalyst comprises at least one nano-substrate structure and at least one atomic site, the atomic site comprises one or more than two chemical elements of Ru, Rh, Ag, Au, Pt, Pd, Os, Ir, preferably one or two of Ru and Au.

[0012] In some embodiments, the atomic site further comprises one or more than two chemical elements of Mn, Co, Fe, Al, Cu, Ni, Zn, Ti, La, preferably one or more than two of Co, Fe, Mn.

[0013] In some embodiments, the energy radiation is selected from at least one of light radiation and thermal radiation, preferably light radiation.

[0014] In some embodiments, the distance between the nano-substrate structure and the atomic site is less than or equal to 5 nm, preferably less than or equal to 1 nm, more preferably less than 0.1 nm, most preferably they are in close contact.

[0015] In some embodiments, the atomic site is combined with the nano-substrate structure, for example, physically or chemically.

[0016] In some embodiments, the mass percentage of the atomic site to the nano-substrate structure is less than or equal to 50%, preferably 0.01% to 30%, preferably 0.01% to 5%, more preferably 0.1% to 2%, most preferably 0.1% to 1%.

[0017] In some embodiments, the atomic site is loaded on the surface, internal channel of the nano-substrate structure, or distributed in the internal lattice of the nano-substrate structure, preferably each atomic site is uniformly distributed, and

[0018] Each atomic site is spaced apart by 0.2-500 nm, preferably 1-50 nm, more preferably 1-20 nm.

[0019] In certain embodiments, the nanosubstrate structure is selected from the group consisting of Mn, Co, Ce, Fe, Al, Ca, Ce, Cu, Ni, Ti, Zn, Si, Mo, Bi, V, C, N and oxides, nitrides, sulfides, carbides, hydroxides, chlorides and metal organic frameworks (MOF) thereof, preferably a metal organic framework, Ti02, AI2O3, or Ce02.

[0020] In certain embodiments, the composite catalyst is a (RuCo-Ti02) catalyst with Ru and Co supported or bound to Ti02, a (Ru-AI2O3) catalyst with Ru supported or bound to AI2O3, a (Au-AI2O3) catalyst with Au supported or bound to AI2O3, or a (Au-Ce02) catalyst with Au supported or bound to Ce02.

[0021] In preferred embodiments, at least one dimension of the nanosubstrate structure is about 1 nm to about 1000 nm, preferably about 70 nm to about 1000 nm, about 100 nm to about 800 nm, about 200 nm to about 500 nm in length, width, or height.

[0022] In preferred embodiments, the nanosubstrate structure is each independently about 1 nm to about 3000 nm in length, width, or height, preferably about 100 nm to about 3000 nm, about 500 nm to about 2500 nm, or about 1000 nm to about 2000 nm in length, and / or about 1 nm to about 1000 nm, about 70 nm to about 1000 nm, about 100 nm to about 800 nm, or about 200 nm to about 500 nm in width or height, or

[0023] The nanosubstrate structure is each independently about 1 to about 20, preferably about 1 to about 10, or about 2 to about 8 in aspect ratio.

[0024] In certain embodiments, the nanosubstrate structure is spherical, spiky, flaky, needle-like, grass-like, columnar, polyhedral, three-dimensional pyramidal, cubic, plate-like, hemispherical, irregular three-dimensional shape, porous structure, or any combination thereof in shape.

[0025] In certain embodiments, the plurality of atomic sites are arranged in a pattern on the nanosubstrate structure, preferably in a plurality of layers, or

[0026] The plurality of atomic sites are randomly dispersed in and / or on the nanosubstrate structure.

[0027] In certain embodiments, the energy radiation is such that the reaction is carried out at a temperature between about 20 °C and about 500 °C, preferably about 50 °C to about 300 °C, about 70 °C to about 250 °C, about 90 °C to about 200 °C, about 100 °C to about 200 °C, about 100 °C to about 180 °C, about 110 °C to about 160 °C, about 120 °C to about 150 °C, about 130 °C to about 150 °C, and

[0028] The unit catalyst activity for producing hydrogen is greater than 2 pmol g -1 h -1 , preferably greater than 3 pmol g -1 h -1 , more preferably greater than 7 pmol g -1 h -1 .

[0029] In certain embodiments, the reaction is initiated using light radiation or heat radiation, and the reaction is continued using light radiation or heat radiation, wherein

[0030] The light radiation has a light radiation power of 200-1500 W / m 2 , preferably 200-1000 W / m 2 , most preferably 500-1000 W / m 2 .

[0031] In certain embodiments, the light radiation increases the temperature of the composite catalyst and the hydrogen-containing source, preferably being the only source of increased temperature.

[0032] In certain embodiments, the hydrogen-containing source is selected from the group consisting of water, saturated alcohol, carboxylic acid, and phenol, and any combination thereof, preferably water.

[0033] In certain embodiments, when the atomic sites comprise two or more chemical elements and are single atoms, the two or more elements can be arranged in an interval or randomly.

[0034] In certain embodiments, when the atomic sites are atomic clusters, the composition of each atomic cluster can be the same or different, for example, each atomic cluster can comprise different element composition and / or different number of atoms. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The gas chromatogram of the gas phase product after reaction using Ru-Al203 composite catalyst and heat radiation with liquid water as raw material is shown.

[0036] Figure 2The gas chromatogram of the gas phase product after reaction with Au-Al2O3 composite catalyst and thermal radiation using liquid water as raw material is shown.

[0037] Figure 3 The transmission electron microscopy (TEM) image of the CoRu-TiO2 composite catalyst is shown. DETAILED DESCRIPTION

[0038] The present application shows that, unexpectedly, it is possible to convert a hydrogen-containing source, preferably water, into hydrogen molecules in the presence of a composite catalyst with plasmonic action, using light radiation and / or thermal radiation as energy input.

[0039] Before the application is further described, certain terms used in the specification, examples, and appended claims are collected in the following sections. The definitions provided herein are to be read in light of the remainder of the application and are to be understood by those of ordinary skill in the art. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] Definitions

[0041] The term "catalyst" as used herein refers to a substance that exhibits the effect of increasing the rate of a chemical reaction by lowering the activation energy of the reaction. The rate- increasing effect is called "catalysis". Catalysts are not consumed in the catalyzed reaction, and therefore they can continue to catalyze further reactions of the reactants.

[0042] The term "plasmonic donor" as used herein refers to a conductor whose real part of the dielectric constant is negative. When excited by electromagnetic radiation, a plasmonic donor can provide surface plasmons.

[0043] The term "temperature dependence" as used herein refers to a property that can change when the temperature is changed by a given level. The temperature difference that changes the property can be any degree, such as 0.1 °C, 1 °C, 5 °C, 10 °C, 100 °C, or 1000 °C.

[0044] The term "chemical element" as used herein refers to a chemical substance consisting of atoms with the same number of protons in the atomic nucleus. Specifically, a chemical element is an element recorded in the periodic table of chemical elements. Chemical elements include natural elements and synthetic elements. Chemical elements also include elements with more than 118 protons in the atomic nucleus that have not yet been discovered.

[0045] The term "bound" or "loaded" as used herein refers to being bound or loaded in a physical manner or a chemical manner in a surface, internal pores, or internal lattice, wherein the physical manner includes van der Waals forces, metal bonds, and other conventional physical binding manners, and the chemical manner includes ionic bonds, covalent bonds, coordination bonds, and other conventional chemical binding manners.

[0046] The term "alloy" as used herein refers to a mixture of metals or a mixture of metals and other elements. An alloy is defined by the property of metallic bonding. An alloy can be a solid solution of a metal element (single phase) or a mixture of metal phases (two or more solutions).

[0047] The term "unit catalyst activity" as used herein refers to the number of moles of product produced per unit mass of active catalyst per unit time under certain reaction conditions. Specifically, unit catalyst activity = moles of reaction product / mass of active catalyst / reaction time.

[0048] The term "intimate contact" as used herein refers to substantially no gap between the two, for example, the distance between the two is less than or equal to 1 nm, less than or equal to 0.1 nm, or substantially 0 nm, preferably forming a metallic bond or a coordination bond.

[0049] The term "saturated alcohol" as used herein refers to a saturated hydrocarbon compound substituted with an -OH group, for example, C1-C8 saturated alcohol, more preferably C1-C4 saturated alcohol, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol. 15 saturated alcohol, preferably C1-C8 saturated alcohol, more preferably C1-C4 saturated alcohol, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol.

[0050] The term "carboxylic acid" as used herein refers to a saturated hydrocarbon compound substituted with a -COOH group, for example, C1-C8 carboxylic acid, more preferably C1-C4 carboxylic acid, such as formic acid, acetic acid, propionic acid, isopropionic acid, butyric acid, isobutyric acid. 15 carboxylic acid, preferably C1-C8 carboxylic acid, more preferably C1-C4 carboxylic acid, such as formic acid, acetic acid, propionic acid, isopropionic acid, butyric acid, isobutyric acid.

[0051] The term "phenol" as used herein refers to a compound comprising an -OH directly attached to an aromatic ring, wherein the aromatic ring is a monocyclic, bicyclic or tricyclic ring comprising 5-25 carbon atoms, preferably 5-20 carbon atoms, most preferably 5-15 carbon atoms, more preferably 6-12 carbon atoms, such as benzene, naphthalene.

[0052] The term "metal-organic framework (MOF)" as used herein refers to an organic-inorganic hybrid material with intramolecular pores or a metal-organic framework structure with a periodic network structure formed by self-assembly of organic ligands and metal ions or clusters. The MOF can comprise transition metals, rare earth metals, main group metals such as alkali metals and alkaline earth metals, etc. as metal elements, for example, comprising Cu, Zn, Cd, Fe, Ti, Mn, Al and Co, preferably comprising Ti, and further comprising non-metal elements such as O, N, S, P, halogens (e.g. F, Cl, Br, I). The MOF can be prepared by methods known in the art, such as evaporation solvent method, diffusion method, hydrothermal or solvothermal method, ultrasonic and microwave method, etc.

[0053] Plasmonic composite catalyst

[0054] One aspect of the present application is a plasmonic recombination catalyst for generating hydrogen molecules by light radiation and / or heat radiation.

[0055] Without wishing to be bound by theory, the plasmonic recombination catalyst of the present application interacts with the raw materials in the reaction to reduce the activation energy of the reaction, thereby enabling the reaction to be initiated by light radiation and / or heat radiation, and increasing the reaction rate.

[0056] The plasmonic recombination catalyst of the present application comprises two structures: atomic sites and nano-substrate structures, wherein the atomic sites and the nano-substrate structures are in contact with each other. In preferred embodiments, the mass percentage of the atomic sites to the nano-substrate structures in the plasmonic recombination catalyst is less than or equal to 50%, preferably 0.01% to 30%, preferably 0.01% to 5%, more preferably 0.1% to 2%, most preferably 0.1% to 1%.

[0057] Atomic sites

[0058] The term "atomic sites" as used herein refers to mutually independent metal single atoms and / or mutually independent atomic clusters comprising 2-25, preferably 2-20 metal atoms, which are stably bound or supported on the surface and / or inside pores and / or inside the crystal lattice of the nano-substrate structure, preferably uniformly distributed in the nano-substrate structure, more preferably uniformly distributed on the surface of the nano-substrate structure. The atoms in the metal single atoms or the atomic clusters are present in a valence state between the 0 valence state and the highest valence state usually present for the metal, for example, an average valence state of the metal atoms is 0 to +4, or 0 to +3, or 0 to +2, or 0 to +1, preferably 0. The interatomic distance in the atomic clusters is less than 1 nm, preferably 0.1-0.5 nm.

[0059] The atoms in the atomic sites and the atoms in the nano-substrate structure are bound by physical or chemical means, for example, by van der Waals forces, metal bonds and other conventional physical binding means, or ionic bonds, covalent bonds, coordination bonds and other conventional chemical binding means, for example, by metal bonds to form alloys, or by coordination bonds to form complexes.

[0060] When the atomic sites are mutually independent metal monomers, the interaction between the metal monomers and the atoms in the nano-substrate structure can prevent the metal monomers from agglomerating, making them more stable. In some embodiments, in the catalytic metal monomer sites, all of the catalytic metal exists in the form of isolated atoms, i.e., the dispersion of catalytic metal atoms is 100%, which maximizes the use of catalytic metal atoms; preferably, all of the catalytic metal atoms are directly fixed to the surface of the nano-substrate structure, the catalytic metal atoms form 100% of the interface atoms, which maximizes the use of metal-substrate interface interaction to optimize catalytic performance.

[0061] When the atomic sites are mutually independent metal clusters, the metal clusters are combined with the atoms in the nano-substrate structure by physical or chemical means. The metal clusters are stably dispersed on and / or in the nano-substrate structure.

[0062] When the atomic sites are single atoms of a single metal element, in some embodiments, the single metal element simultaneously serves as a plasmonic donor and a donor of catalytic properties, and the nano-substrate structure provides physical support; in other embodiments, the single metal element serves as a plasmonic donor, the nano-substrate structure provides physical support, and as a donor of catalytic properties.

[0063] When the atomic sites are metal clusters, in some embodiments, some atomic clusters containing specific elements serve as plasmonic donors, and some atomic clusters containing specific elements serve as donors of catalytic properties, and the nano-substrate structure provides physical support; in other embodiments, the atomic clusters serve as plasmonic donors, the nano-substrate structure provides physical support, and as donors of catalytic properties.

[0064] In other embodiments, the atomic sites and the nano-substrate structure jointly act as plasmonic donors and donors of catalytic properties, and the nano-substrate structure provides physical support.

[0065] Nano-substrate structure

[0066] As used herein, the term "nanosubstrate structure" refers to a structure having a size range in the nanometer scale, i.e., at least one dimension of length, width, or height is in the range of about 1 nm to about 1000 nm, preferably about 70 nm to about 1000 nm, about 100 nm to about 800 nm, about 200 nm to about 500 nm. Nanosubstrate structures can have dimensions exceeding 1000 nm, for example, having a length in the micrometer scale, such as 1 μιη to 5 μιη. In certain instances, tubular and fibrous structures having only two dimensions in the nanometer range are also considered nanosubstrate structures. Materials having nanosubstrate structures can exhibit size-dependent properties that are significantly different from those observed in bulk materials.

[0067] The nanosubstrate structures of the present application are each independently about 1 nm to about 3000 nm in length, width, or height. Preferably, they are about 100 nm to about 3000 nm in length, more preferably about 500 nm to about 2500 nm, still more preferably about 1000 nm to about 2000 nm. Preferably, they are about 1 nm to about 1000 nm in width or height, preferably about 70 nm to about 1000 nm, more preferably about 100 nm to about 800 nm, still more preferably about 200 nm to about 500 nm.

[0068] The nanosubstrate structures of the present application are each independently about 1 to about 20 in aspect ratio (i.e., the ratio of length to width / height), preferably about 1 to about 10, or about 2 to about 8 in aspect ratio. The nanosubstrate structures of the present application can also have a relatively low aspect ratio, such as about 1 to about 2.

[0069] The nanosubstrate structures of the present application are each independently about 1 to about 20 in aspect ratio (i.e., the ratio of length to width / height), preferably about 1 to about 10, or about 2 to about 8 in aspect ratio. The nanosubstrate structures of the present application can also have a relatively low aspect ratio, such as about 1 to about 2.

[0070] The nanosubstrate structures are selected from the group consisting of Mn, Co, Ce, Fe, Al, Ca, Ce, Cu, Ni, Ti, Zn, Si, Mo, Bi, V, C, N, and oxides, nitrides, sulfides, carbides, hydroxides, chlorides, and metal organic frameworks thereof.

[0071] As used herein, the term "nanosubstrate structure" includes more than 25, preferably more than 30 atoms.

[0072] The plurality of nano-substrate structures of the present application can be arranged in a pattern on a substrate, preferably in a plurality of layers, or the plurality of nano-substrate structures can be randomly dispersed in a medium. For example, the nano-substrate structures can be bound to a substrate. In this case, the nano-substrate structures are generally not aggregated with one another, but are arranged or packed in an ordered fashion. Alternatively, the plurality of nano-substrate structures can be dispersed in a liquid medium, where each nano-substrate structure is free to move relative to other nano-substrate structures.

[0073] For example, the nano-substrate structures can have a spike-like or grass-like geometry. Optionally, the nano-substrate structures are flake-like in geometry with a relatively thin thickness. Preferably, the nano-substrate structures have a nano-jungle, nano-grass, and / or nano-snowflake configuration. The nano-substrate structures can have a relatively large aspect ratio, such nano-substrate structures can take the form of nano-spikes, nano-snowflakes or nano-needles. The aspect ratio can be about 1 to about 20, about 1 to about 10, or about 2 to about 8. Preferably, the length of the nano-substrate structures can be about 100 nm to about 3000 nm, about 500 nm to about 2500 nm, or about 1000 nm to about 2000 nm; the width or height can be about 1 nm to about 1000 nm, about 70 nm to about 1000 nm, about 100 nm to about 800 nm, or about 200 nm to about 500 nm.

[0074] The nano-substrate structures can be bound to a substrate. Thus, the nano-substrate structures are generally not aggregated together, but are arranged in an ordered fashion. The substrate can be formed of a metallic or polymeric material (e.g., polyimide, PTFE, polyester, polyethylene, polypropylene, polystyrene, polyacrylonitrile, etc.).

[0075] In other examples, the nano-substrate structures have a spherical, cylindrical, polyhedral, three-dimensional pyramidal, cubical, plate-like, hemispherical, irregular three-dimensional shape, porous structure, or any combination thereof. Such nano-substrate structures are each independently about 1 nm to about 1000 nm, about 70 nm to about 1000 nm, about 100 nm to about 800 nm, or about 200 nm to about 500 nm in length, width, height.

[0076] In addition, the plasmonic atomic catalysts of the present application can function in various states, such as being dispersed, aggregated, or attached / grown on the surface of other materials. In a preferred embodiment, the plasmonic atomic catalysts are dispersed in a medium, which is preferably a reactant of the reaction, such as water.

[0077] Method of producing hydrogen molecules

[0078] Another aspect of the present application is a method for producing hydrogen molecules by optical and / or thermal irradiation comprising the steps of:

[0079] contacting a plasmonic recombination catalyst with at least one hydrogen source; and

[0080] optically and / or thermally irradiating the plasmonic recombination catalyst, the hydrogen source to produce hydrogen molecules.

[0081] Under the catalytic action of the plasmonic recombination catalyst, the energy irradiation, i.e., optical and / or thermal irradiation, initiates the reaction of the hydrogen source. The reaction of decomposing the hydrogen source, preferably water, to produce hydrogen molecules is an endothermic reaction. Without wishing to be bound by theory, the plasmonic recombination catalyst is able to convert and transfer the energy of the optical and thermal irradiation, thereby sustaining the reaction of the present application. Within a certain temperature range, increasing the temperature can result in a higher energy conversion rate for producing hydrogen molecules.

[0082] The optical and / or thermal irradiation step is carried out at a temperature between about 20 °C to about 800 °C, about 20 °C to about 500 °C, about 50 °C to about 300 °C, about 70 °C to about 250 °C, about 90 °C to about 200 °C, about 100 °C to about 200 °C, about 100 °C to about 180 °C, about 110 °C to about 160 °C, about 120 °C to about 150 °C, about 130 °C to about 150 °C, etc. At the above temperatures, the unit catalyst activity for hydrogen production is greater than 2 pmol g -1 h -1 , preferably greater than 3 pmol g -1 h -1 , more preferably greater than 7 pmol g -1 h -1 .

[0083] The term "heat" as used herein refers to thermal energy that is transferred from one system to another as a result of heat exchange. Thermal energy can be transferred to a reaction system from an external heat source or can be carried by one reaction component to another reaction component. In other words, a reaction component that carries thermal energy prior to the reaction is also referred to as an internal heat source. In certain embodiments, the thermal irradiation increases the temperature of the plasmonic recombination catalyst and the hydrogen source in the reaction of the present application.

[0084] In the reaction of the present application, the optical irradiation mimics the wavelength composition and intensity of sunlight, and thus it can increase the temperature of the irradiated catalyst and reactants. When the irradiation intensity reaches a certain level, the temperature of the plasmonic recombination catalyst and the hydrogen source is increased by the optical irradiation. Preferably, the optical irradiation is the only source for increasing the temperature.

[0085] In the reaction of the present application, the reaction continues under light irradiation after the reaction is initiated. The term "light" as used herein refers to electromagnetic waves having a wavelength between about 250 nm and about 2000 nm. In other words, light refers to radiation of visible light. Preferably, in the reaction of the present application, the light irradiation power is lower than the solar irradiation power (i.e. the solar constant). For example, the light irradiation power is 200-1500 W / m 2 , preferably 200-1000 W / m 2 , most preferably 500-1000 W / m 2 . The light irradiation can be sunlight or light emitted from artificial light sources, the light irradiation having a wavelength between about 250 nm and about 2000 nm.

[0086] The reaction time varies depending on the size of the reaction, the irradiation intensity, the temperature and other factors, and the reaction continues using a well-established apparatus and with continuous addition of the hydrogen-containing source. The reaction time can be 0.1 hour or more, preferably 0.1 hour to 1000 hours, preferably 0.1 hour to 500 hours, preferably 0.5 hour to 100 hours, preferably 1 hour to 50 hours, preferably 2 hours to 30 hours, most preferably 4 hours to 20 hours.

[0087] The reaction can be carried out at low pressure, normal pressure or high pressure, and the appropriate reaction pressure can be selected depending on the size of the reaction, the irradiation intensity, the temperature and other factors, for example, the reaction pressure can be at least 1 bar, for example 1 bar to 30 bar, preferably 1 bar to 20 bar, more preferably 1.5 bar to 5 bar.

[0088] Reaction feedstock

[0089] In the reaction of the present application, the reaction raw materials include hydrogen-containing sources such as water, saturated alcohols, carboxylic acids and phenols, preferably water, for example pure water or hard water, which can be in gaseous or liquid form.

[0090] Reaction product

[0091] The reaction of the present application is capable of producing hydrogen molecules. Without wishing to be bound by theory, the reaction mechanism of the present application can include the decomposition and recombination of various reaction raw material molecules on the atomic sites and nano-substrate structure of the plasmonic composite catalyst.

[0092] Examples

[0093] Example 1 Preparation of composite catalysts

[0094] Ru-Al 2 O 3 (Ru supported or bound to Al 2 O 3 ) composite catalyst and Au-Al 2O 3 (Au supported or bound to Al 2 O 3 ) composite catalyst were prepared by the following method: RuCo-TiO

[0095] RuCl3was dissolved in 5 mL of deionized water and mixed under sonication for 60 min at room temperature. Then, 2 g of activated alumina was added and mixed under sonication for 60 min at 40 °C. The resulting dry solid was collected and washed with deionized water five times to obtain a Ru-Al2O3precursor. A solution of 20 mL of sodium hydroxide pre-adjusted to pH 12.0 and 0.4 g of sodium borohydride (NaBH4) solid was slowly added to the precursor, which was stirred until homogenization and then filtered under suction. The resulting solid was washed with deionized water three times and dried at 80 °C under nitrogen atmosphere to obtain the Ru-Al2O3composite catalyst. Au-Al2O3composite catalyst was obtained by replacing RuCl3with 3.4 mg of chloroauric acid (HAuCl4) in the above procedure.

[0096] (Ru and Co supported or bound to TiO 2 ) composite catalyst Composite catalysts were prepared by the following method: 2 Figure 3

[0097] A mixture of 0.0020 g of ruthenium trichloride hydrate (RuCl3.xH2O) and 0.0014 g of cobalt nitrate hexahydrate (Co(NO3)2.6H2O) was dissolved in 100 mL of deionized water and sonicated for 10 min. This solution was slowly added to the above solution A. The suspension was aged at room temperature for 2.5 h. The resulting precipitate was washed by centrifugation three times at 12500 rpm with deionized water and dried in an oven at 60 °C for 12 h to obtain the RuCo-TiO2composite catalyst. A high resolution transmission electron microscopy (HRTEM) image of the RuCo-TiO2composite catalyst is shown in FIG. 1. Au-CeO

[0098] (Au supported or bound to CeO 2 ) composite catalyst Composite catalysts were prepared by the following method: 2 Example 2 Thermocatalytic reaction to produce hydrogen

[0099] ​1.73 g of cerium nitrate hexahydrate (CeNO3·6H2O) and 0.0068 g of tetrachloroauric acid (HAuCl4·3H2O) were dissolved in 10 mL of deionized water. After complete dissolution, the solution was slowly added dropwise to 70 mL of 6 mol / L sodium hydroxide (NaOH) solution. The mixture was stirred continuously at room temperature for 30 min. The suspension was then transferred to a 100 mL stainless steel reactor lined with polytetrafluoroethylene and kept at 120 ℃ for 12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The precipitate was collected by centrifugation and washed with deionized water until the pH of the washing solution reached 7. The precipitate was then dried in an oven at 60 ℃ for 12 h. The dried sample was thoroughly ground and placed in a tube furnace. The temperature was increased to 400 ℃ at a rate of 5 ℃ / min under air atmosphere and maintained for 2 h to obtain the Au-CeO2 composite catalyst used in the experiment.

[0100] Figure 1

[0101] The catalyst used was the Ru-Al2O3 composite catalyst prepared according to Example 1. Al2O3 is a nano-substrate structure, which, according to SEM characterization, consists of irregularly shaped spherical particles with a diameter of 500-1000 nm. Isolated Ru metal single atoms are uniformly distributed on the surface of Al2O3, with a spacing of 5-20 nm between the metal single atoms.

[0102] 0.1 g of Ru-Al₂O₃ composite catalyst and 6 mL of ultrapure water were added to a 35 mL sealable pressure iron tube. The air inside the tube was purged with Ar, and then 4 bar of Ar was introduced. The iron tube was placed in a temperature-controlled oven and heated to carry out the reaction. The temperature inside the oven was controlled at 130℃±10℃, and the reaction was carried out continuously for 18 h.

[0103] Following the thermocatalytic reaction, the hydrogen content in the gas within the reaction tube was characterized using thermal conductivity detector (TCD) gas chromatography. The gas chromatogram of the products obtained after the thermocatalytic reaction using the Ru-Al₂O₃ composite catalyst is shown below. Example 3 Thermocatalytic reaction to produce hydrogen As shown, the calculated hydrogen content is 2053 ppm, and the catalyst activity per unit volume of hydrogen produced is approximately 6.44 μmol g. -1 h -1 After the above reaction was carried out for 10 cycles (180 h), the catalytic activity of the catalyst for hydrogen production did not decrease.

[0104] Figure 2

[0105] The catalyst used was the Au-Al2O3 composite catalyst prepared according to Example 1. Al2O3 is a nano-substrate structure, which, according to SEM characterization, consists of irregularly shaped spherical particles with a diameter of 500-1000 nm. Isolated Au metal single atoms are uniformly distributed on the surface of Al2O3, with a metal atom spacing of 5-20 nm.

[0106] The thermal catalytic reaction was carried out in the same way as in Example 2 using 0.1 g of Au-Al2O3 composite catalyst. The temperature in the oven was controlled at 130°C ± 10°C, and the reaction was continuously carried out for 18 h.

[0107] The gas after the reaction was characterized by gas chromatography in the same way as in Example 2. The gas chromatogram obtained after the thermal catalytic reaction using the Au-Al2O3 composite catalyst is shown in Figure 2, and the hydrogen content was calculated to be 2890 ppm, and the unit catalyst activity for hydrogen production was about 9.073 μmol g Example 4 Thermocatalytic reaction to produce hydrogen h -1 h -1 After 10 cycles (180 h) of the above reaction, the catalytic activity of the catalyst for hydrogen production was not decreased.

[0108] Example 5 Thermocatalytic reaction to produce hydrogen

[0109] The catalyst used was the Au-CeO2 composite catalyst prepared according to Example 1, and the CeO2 was a nano-substrate structure, which was characterized by SEM to be irregularly shaped spherical particles with a diameter of 400-1500 nm; the isolated Au metal monomers were uniformly distributed on the surface of the CeO2, and the interval between the metal monomers was 5-20 nm.

[0110] The thermal catalytic reaction was carried out in the same way as in Example 2 using 0.1 g of Au-CeO2 composite catalyst. The temperature in the oven was controlled at 130°C ± 10°C, and the reaction was continuously carried out for 18 h.

[0111] The gas after the reaction was characterized by gas chromatography in the same way as in Example 2. The hydrogen content was calculated to be 1862 ppm, and the unit catalyst activity for hydrogen production was about 5.845 μmol g -1 h -1 After 10 cycles (180 h) of the above reaction, the catalytic activity of the catalyst for hydrogen production was not decreased.

[0112] Example 6 Photocatalytic reaction to produce hydrogen

[0113] The catalyst used was the RuCo-TiO2 composite catalyst, and the TiO2 was a nano-substrate structure, which was characterized by SEM to be irregularly shaped spherical particles with a diameter of 600-1500 nm; the isolated Ru and Co metal monomers or clusters were uniformly distributed on the surface of the TiO2, and the interval between the metal monomers or clusters was 5-20 nm.

[0114] A thermal catalytic reaction was performed in the same way as in Example 2 using 0.2 g of RuCo-TiO2 composite catalyst. The temperature in the oven was controlled at 130 °C ± 10 °C and the reaction was continuously performed for 18 h.

[0115] The gas after the reaction was characterized by gas chromatography in the same way as in Example 2. The hydrogen content was calculated to be 6863 ppm and the unit catalyst activity for hydrogen production was about 10.77 pmol g -1 h -1 of catalyst per hour. The catalytic activity of the catalyst for hydrogen production did not decrease after the above reaction was continuously performed for 10 cycles (180 h).

[0116] ​

[0117] The catalyst used was the RuCo-TiO2 composite catalyst described in Example 5.

[0118] A 35 mL volume sealable pressure glass tube was charged with 0.2 g of RuCo-TiO2 composite catalyst and 6 mL of ultrapure water, the internal air was purged with Ar and 4 bar of Ar was charged. The glass tube was laid on glass wool so that the catalyst and water were evenly spread and a halogen lamp with controllable voltage was used to irradiate vertically from above. The incident light intensity was about 1000 W / m 2 A thermocouple was connected to the lower half of the glass tube to monitor the temperature. The temperature of the glass tube was controlled at 50 °C ± 10 °C and the photocatalytic reaction was continuously performed for 18 h with light irradiation.

[0119] After the photocatalytic reaction, the gas after the reaction was characterized by gas chromatography in the same way as in Example 2 and the hydrogen content was obtained to be 1848 ppm. The unit catalyst activity for hydrogen production was calculated to be about 2.901 pmol g -1 h -1 of catalyst per hour. The catalytic activity of the catalyst for hydrogen production did not decrease after the above reaction was continuously performed for 10 cycles (180 h).

[0120] The results of Examples 2 to 6 show that the method of the present application can efficiently directly convert readily available raw materials into hydrogen gas using cost-effective catalysts under mild overall reaction conditions, for example, with a lower light radiation power than that of sunlight.

[0121] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Methods reported herein can be carried out in any order unless otherwise specified in the particular sequence disclosed.

[0122] The representative examples are intended to help illustrate the application, and are not intended to, nor should they be construed to, limit the scope of the application. Indeed, various modifications of the examples, in addition to those shown and described herein, will become apparent to those skilled in the art, including embodiments and scientific and patent literature references cited herein. The examples contain important additional information, exemplification, and guidance that can be adapted to the practice of this application in its various embodiments and equivalents.

Claims

1. A method for producing hydrogen by energy radiation, comprising: The composite catalyst is brought into contact with at least one hydrogen-containing source, and Energy is radiated onto the composite catalyst and the hydrogen-containing source to produce hydrogen molecules, wherein... The composite catalyst comprises at least one nanostructure and at least one atomic site, wherein the atomic site comprises one or more chemical elements selected from Ru, Ag, Au, Pt, and Pd. The nanostructure is a metal-organic framework, TiO2, Al2O3, or CeO2. The energy radiation mentioned is thermal radiation. The energy radiation causes the reaction to take place at a temperature between 120 °C and 300 °C. The reaction is carried out at a pressure of 1.5 bar to 5 bar. The hydrogen source is water.

2. The method of claim 1, wherein, The atomic sites contain one or both of Ru and Au.

3. The method of claim 1, wherein The atomic sites also contain one or more chemical elements selected from Mn, Co, Fe, Al, Cu, Ni, Zn, Ti, and La.

4. The method of claim 1, wherein The atomic sites also contain one or more chemical elements selected from Co, Fe, and Mn.

5. The method of claim 1, wherein The distance between the nanostructure and the atomic sites is less than or equal to 5 nm.

6. The method of claim 5, wherein The distance between the nanostructure and the atomic sites is less than or equal to 1 nm.

7. The method of claim 5, wherein The distance between the nanostructure and the atomic sites is less than 0.1 nm.

8. The method of claim 5, wherein The nanostructure and the atomic sites are in close contact.

9. The method of claim 1, wherein The atomic sites are bonded to the nanostructure.

10. The method of claim 9, wherein The atomic sites are physically or chemically bonded to the nanostructure.

11. The method of claim 1, wherein The atomic sites account for less than or equal to 50% of the mass percentage of the nanostructure.

12. The method of claim 11, wherein The atomic sites account for 0.01% to 30% of the mass of the nanostructure.

13. The method of claim 11, wherein The atomic sites account for 0.01% to 5% of the mass of the nanostructure.

14. The method of claim 11, wherein The atomic sites account for 0.1% to 2% of the mass of the nanostructure.

15. The method of claim 11, wherein The atomic sites account for 0.1% to 1% of the mass of the nanostructure.

16. The method of claim 1, wherein The atomic sites are loaded on the surface of the nanostructure, in the internal channels, or distributed in the internal lattice of the nanostructure. The spacing between each atomic site is 0.2-500 nm.

17. The method of claim 16, wherein Each atomic site is evenly distributed.

18. The method of claim 16, wherein The spacing between each atomic site is 1-50 nm.

19. The method of claim 16, wherein The spacing between each atomic site is 1-10 nm.

20. The method according to any one of claims 1 to 19, wherein The composite catalyst is a catalyst supported on or combined with TiO2 by Ru and Co, a catalyst supported on or combined with Al2O3 by Ru, a catalyst supported on or combined with Al2O3 by Au, or a catalyst supported on or combined with CeO2 by Au.

21. The method according to any one of claims 1 to 19, wherein The length, width, and height of the nanostructure have at least one dimension ranging from 1 nm to 1000 nm.

22. The method of claim 21, wherein The length, width, and height of the nanostructure have at least one dimension ranging from 70 nm to 1000 nm.

23. The method of claim 21, wherein The length, width, and height of the nanostructure have at least one dimension ranging from 100 nm to 800 nm.

24. The method of claim 21, wherein The length, width, and height of the nanostructure have at least one dimension ranging from 200 nm to 500 nm.

25. The method of any one of claims 1 to 19, wherein Each of the nanostructures has an independent length, width, and height ranging from 1 nm to 3000 nm, or Each of the nanosubstrate structures has an aspect ratio of 1 to 20.

26. The method of claim 25, wherein The length of the nanostructure is 100 nm to 3000 nm, and / or the width or height is 1 nm to 1000 nm.

27. The method of claim 26, wherein The length of the nanostructure is 500 nm to 2500 nm.

28. The method of claim 26, wherein The length of the nanostructure is 1000 nm to 2000 nm.

29. The method of claim 26, wherein The width or height of the nanostructure is 70 nm to 1000 nm.

30. The method of claim 26, wherein The width or height of the nanostructure is 100 nm to 800 nm.

31. The method of claim 26, wherein The width or height of the nanostructure is 200 nm to 500 nm.

32. The method of claim 25, wherein Each of the nanosubstrate structures has an aspect ratio of 1 to 10 independently.

33. The method of claim 25, wherein Each of the nanosubstrate structures has an aspect ratio of 2 to 8.

34. The method according to any one of claims 1 to 19, wherein The shape of the nanostructure can be spherical, needle-like, columnar, three-dimensional cone, cubic, sheet-like, hemispherical, porous, or any combination thereof.

35. The method according to any one of claims 1 to 19, wherein The shape of the nanostructure can be spikes, sheets, polyhedra, or any combination thereof.

36. The method of any one of claims 1 to 19, wherein The plurality of said atomic sites are arranged in a patterned configuration on the nanostructure, or Multiple atomic sites are randomly dispersed in and / or on the surface of the nanostructure.

37. The method of claim 36, wherein Multiple atomic sites are arranged in a patterned, multilayered manner on the nanostructure.

38. The method according to any one of claims 1 to 19, wherein The energy radiation causes the reaction to take place at a temperature between 120 °C and 250 °C.

39. The method of claim 38, wherein The energy radiation causes the reaction to take place at a temperature between 120 °C and 200 °C.

40. The method of claim 38, wherein The energy radiation causes the reaction to take place at a temperature between 120 °C and 180 °C.

41. The method of claim 38, wherein The energy radiation causes the reaction to take place at a temperature between 120 °C and 160 °C.

42. The method of claim 38, wherein The energy radiation causes the reaction to take place at a temperature between 120 °C and 150 °C.

43. The method of claim 38, wherein The energy radiation causes the reaction to take place at a temperature between 130 °C and 150 °C.

44. The method according to any one of claims 1 to 19, wherein The reaction is initiated by thermal radiation, and the reaction is continued by thermal radiation.

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