An apparatus and method for hydrogen production from ethanol reforming based on photothermal-driven vapor phase reaction

Abstract

This invention discloses an ethanol reforming hydrogen production device based on a photothermal-driven vapor phase reaction, comprising a shell, a support, a porous transport layer, a porous evaporation layer, and a porous catalyst layer. The porous transport layer is placed inside the shell, and the porous evaporation layer is placed on top of the porous transport layer. The support is located outside the porous transport layer and the porous evaporation layer, serving to support the porous catalyst layer and suspend it above the porous evaporation layer. The porous transport layer and the porous evaporation layer are made of SiO2, Ti4O7, and carbomer; the porous catalyst layer is made of SiO2, Ti4O7, carbomer, photothermal material Fe2O3, and catalyst Pt. This invention utilizes the photothermal effect of solar energy to locally generate heat at the reaction site, resulting in high hydrogen production, high product selectivity, and no CO2 emissions, making it suitable for efficient and green industrial hydrogen production.

Description

Technical Field

[0001] This invention relates to the field of ethanol reforming for hydrogen production technology, and particularly to an ethanol reforming apparatus and method for hydrogen production based on photothermal driven vapor phase reaction. Background Technology

[0002] Utilizing solar energy to drive hydrogen production from bioethanol aqueous solutions is a crucial pathway for green hydrogen production and my country's clean energy transition. However, the ultimate efficiency and economic feasibility of this process are highly dependent on the selectivity of the reaction pathway and the contact mode between the reactants and the catalyst. Currently, the mainstream technological routes can be divided into traditional thermocatalysis relying on external heat sources and traditional photocatalysis directly utilizing photon energy; both have inherent bottlenecks.

[0003] Traditional thermocatalytic technology relies on external energy to heat the entire system. A typical system includes a separate external evaporator, a preheater to preheat the gaseous reactants to the reaction temperature, and a fixed-bed reactor packed with catalyst. Liquid ethanol-water solution is first vaporized in the evaporator, and then the preheated mixed vapor is introduced into the reactor for catalytic reforming. While this method can achieve relatively high hydrogen yields (up to approximately 300 mmol·g), it is not universally applicable. -1 ·h -1 While capable of producing hydrogen on a scale of 100 kJ, this technology requires catalytic reactions at temperatures exceeding 400 °C, resulting in extremely high energy consumption. The required heat is entirely dependent on external energy input (such as electricity and heat), with approximately 400 kJ of energy consumed to generate 1 mol of hydrogen. Due to the high reaction temperature and acidic sites on the catalyst surface, side reactions such as C / C bond breakage and water-vapor shift are easily triggered, leading to unsatisfactory selectivity of the target product. This technology generally treats "evaporation of reactants" and "catalytic conversion" as two independent and separate unit operations, which inevitably requires the use of complex auxiliary systems such as independent evaporators and preheaters during the reaction, resulting in high equipment investment and maintenance costs.

[0004] Traditional photocatalysis involves directly dispersing powdered semiconductor photocatalysts in an ethanol-water solution. Under illumination, the catalyst absorbs photons to generate photogenerated electron-hole pairs, which then catalyze the reaction between ethanol and water molecules in the liquid phase. This system avoids the high-temperature energy consumption of traditional thermocatalysis and is simple. However, its fundamental bottlenecks are: low mass transfer efficiency of reactants in the liquid phase; easy recombination of photogenerated electrons and holes, leading to low efficiency; direct contact between the catalyst and the liquid, easily triggering deep oxidation side reactions such as C / C bond breaking, inevitably leading to CO2 generation, and difficulty in precisely controlling the reaction pathway; and difficulty in separating and recovering the catalyst from the solution after the reaction, increasing operating costs and potentially causing catalyst loss and secondary pollution. Therefore, its hydrogen yield is generally low, ranging from 1-30 mmol·g. -1 ·h -1The levels are low, and it is difficult to completely avoid CO2 generation. Summary of the Invention

[0005] Objective: In order to overcome the shortcomings of the existing technology, the present invention provides an ethanol reforming hydrogen production device and method based on photothermal driven vapor phase reaction, which uses sunlight as the only energy input, has a simple structure, no CO2 emissions, and high product selectivity.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides an ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction, comprising a shell, a support, a porous transport layer, a porous evaporation layer and a porous catalyst layer;

[0008] The porous transport layer is placed inside the housing, and the porous evaporation layer is placed on the porous transport layer;

[0009] The support is located outside the porous transport layer and the porous evaporation layer, and is used to support the porous catalyst layer and suspend the porous catalyst layer above the porous evaporation layer.

[0010] The porous transport layer, porous evaporation layer and porous catalyst layer are of the same size and each has an array of pores;

[0011] The porous transport layer is made of SiO2, Ti4O7 and carbomer; the mass ratio of SiO2, Ti4O7 and carbomer is (1-30):(5-30):(1-10).

[0012] The porous evaporation layer is made of SiO2, Ti4O7 and carbomer; the mass ratio of SiO2, Ti4O7 and carbomer is (1-30):(5-30):(1-10).

[0013] The porous catalyst layer includes a porous catalyst layer substrate and metal oxides and noble metal elements supported on the porous catalyst layer substrate; the materials of the porous catalyst layer substrate include SiO2, Ti4O7 and carbomer, and the mass ratio of SiO2, Ti4O7 and carbomer is (1-30):(5-30):(1-10).

[0014] This invention provides an ethanol reforming hydrogen production device that uses sunlight as the sole energy input. It constructs a highly integrated vapor-phase reaction system that integrates evaporation, phase change, transport, and reaction processes. Specifically, a porous transport layer is completely immersed in an aqueous ethanol solution and transports the solution to the porous evaporation layer. The porous evaporation layer acts as a "steam engine," efficiently converting liquid reactants into steam under sunlight through a photothermal effect. Simultaneously, a porous catalyst layer, loaded with metal oxides as photothermal materials and noble metal elements as catalysts, is precisely suspended above the porous evaporation layer using a specially designed support, forming a directional reaction channel. Driven by thermal convection, the steam rises naturally and automatically and directionally penetrates the porous catalyst layer, thus enabling catalytic reforming to occur in a pure vapor phase environment completely detached from liquid phase contact. This design fundamentally blocks liquid-phase side reaction pathways, simultaneously achieving zero CO2 emissions, highly selective hydrogen production, and ultra-high reaction rates.

[0015] In use, the porous transport layer is completely immersed in an ethanol-water solution, continuously supplying the reaction liquid to the porous evaporation layer via capillary action. The porous evaporation layer is used to efficiently convert the liquid-phase reactants into an ethanol-water mixed vapor under illumination via photothermal effect. A porous catalytic layer, loaded with photothermal materials and catalyst and located directly above the porous evaporation layer, is suspended and acts as a "steam treatment layer." Under illumination, it drives the photocatalytic dehydrogenation reaction of ethanol: ethanol molecules lose electrons and are oxidized to acetaldehyde, while the released protons accept electrons and are reduced to hydrogen, thus achieving selective hydrogen production in the vapor phase.

[0016] The porous design of the porous transport layer, porous evaporation layer and porous catalyst layer allows some light to be transmitted to the porous evaporation layer below, thereby generating a photothermal effect in the porous evaporation layer region and effectively driving the evaporation of the ethanol aqueous solution.

[0017] In some embodiments, the metal oxide includes one or more of Fe2O3, TiO2, and MoS2; the noble metal element is Pt.

[0018] In some embodiments, the horizontal cross-sectional area of ​​the hole is 0.8-1.2 mm. 2 .

[0019] In some embodiments, the preparation method of the porous transport layer and the porous evaporation layer includes: using ink direct writing 3D printing technology, using SiO2, Ti4O7 and carbomer as raw materials, printing a porous transport layer substrate and a porous evaporation layer substrate, freeze-drying for 12-24 h, and calcining the porous transport layer substrate and the porous evaporation layer substrate at 900-1300 ℃ for 2-4 h in a hydrogen atmosphere to obtain the product.

[0020] The 3D printing method includes: first applying 50-300 mg mL... -1 Add 1-10 wt% carbomer aqueous solution to the SiO2 aqueous solution, with a volume ratio of SiO2 aqueous solution to carbomer aqueous solution of (0.8-1.5):1; then add 0.5-3 g of Ti4O7 powder, and adjust the pH of the solution to neutral with NaOH aqueous solution to obtain 3D printing ink; prepare 3D printing model file; fill the injection needle of the 3D printing equipment with 3D printing ink and seal it, and use a stainless steel nozzle with an inner diameter of 0.51 mm to extrude based on the 3D printing model file at a printing pressure of 100-200 KPa. After the printing program is completed, remove the porous transport layer matrix and the porous evaporation layer matrix.

[0021] In some embodiments, the method for preparing the porous catalyst layer includes:

[0022] A porous catalyst layer matrix was printed using ink direct writing 3D printing technology with SiO2, Ti4O7 and carbomer as raw materials.

[0023] After freeze-drying for 12-24 h, the porous catalyst layer substrate is calcined at 900-1300 °C for 2-4 h in a hydrogen atmosphere to obtain the porous catalyst layer material.

[0024] The porous catalyst layer material is loaded with metal oxide nanoparticles through a hydrothermal reaction to obtain a porous catalyst layer material loaded with metal oxide. 0.1-1 mL of 1-20 mM K2PtCl6 solution is added dropwise, and the material is calcined at 200-350 ℃ for 1-3 h in a hydrogen atmosphere to obtain the porous catalyst layer.

[0025] The 3D printing method includes: first applying 50-300 mg mL... -1 Add 1-10 wt% carbomer aqueous solution to the SiO2 aqueous solution, with a volume ratio of SiO2 aqueous solution to carbomer aqueous solution of (0.8-1.5):1; then add 0.5-3 g of Ti4O7 powder, and adjust the pH of the solution to neutral with NaOH aqueous solution to obtain 3D printing ink; prepare 3D printing model file; fill the injection needle of the 3D printing equipment with 3D printing ink and seal it, and use a stainless steel nozzle with an inner diameter of 0.51 mm to extrude it based on the 3D printing model file at a printing pressure of 100-200 KPa. After the printing program is completed, remove the porous catalyst layer substrate.

[0026] In some embodiments, when Fe2O3 is used as a metal oxide, the hydrothermal reaction step includes:

[0027] FeCl3 and / or its hydrates are dissolved in deionized water at a mass ratio of 1:(0.5-2) to prepare a mixed solution;

[0028] Add porous catalyst layer material and 5-15 mL of mixed solution to a hydrothermal reactor, and heat at 80-150 °C for 15-30 h to obtain the first hydrothermal reaction product;

[0029] After the reaction is complete, the first hydrothermal reaction product is dried at 60-100 °C for 1-4 h and calcined at 350-500 °C for 0.5-4 h to obtain the final product.

[0030] In some embodiments, when TiO2 is used as a metal oxide, the hydrothermal reaction step includes:

[0031] Tetrabutyl titanate and 10-15 M hydrochloric acid were dissolved in deionized water at a mass ratio of 1:(1-5) to prepare a mixed solution;

[0032] Add porous catalyst layer material and 5-15 mL of mixed solution to a hydrothermal reactor, and heat at 100-200 °C for 15-30 h to obtain the first hydrothermal reaction product;

[0033] After the reaction is complete, the first hydrothermal reaction product is dried at 60-100 °C for 1-4 h and calcined at 350-500 °C for 0.5-4 h to obtain the final product.

[0034] In some embodiments, when MoS2 is used as a metal oxide, the hydrothermal reaction step includes:

[0035] A mixed solution was prepared by dissolving thiourea and ammonium heptamolybdate and / or their hydrates in deionized water at a mass ratio of 1:(0.5-3);

[0036] Add porous catalyst layer material and 5-15 mL of mixed solution to a hydrothermal reactor, and heat at 100-250 °C for 15-30 h to obtain the first hydrothermal reaction product;

[0037] After the reaction is complete, the first hydrothermal reaction product is dried at 60-100 °C for 4-10 h to obtain the final product.

[0038] In some embodiments, the housing and support are made of glass; the housing is provided with a liquid inlet for adding reaction raw materials into the device; the housing is also provided with a gas outlet for collecting the produced hydrogen gas; the housing is also provided with a liquid outlet for recovering the liquid phase products of the reaction.

[0039] In some embodiments, a condensation jacket is further provided inside the housing for injecting condensate into the space between the condensation jacket and the housing;

[0040] The upper part of the condensing jacket is provided with a condensate outlet, and the lower part of the condensing jacket is provided with a condensate inlet.

[0041] In a second aspect, the present invention provides a method for hydrogen production from ethanol reforming based on a photothermal-driven vapor phase reaction, using the ethanol reforming hydrogen production apparatus based on a photothermal-driven vapor phase reaction as described in the first aspect; the method includes:

[0042] Add 10 vol %-90 vol % of an aqueous ethanol solution to the shell until the porous transport layer is below the surface of the aqueous ethanol solution, the porous evaporation layer is placed on the porous transport layer and above the surface of the aqueous ethanol solution, and the porous catalyst layer is suspended in the aqueous ethanol solution.

[0043] Irradiate with a light source, react for 1.5-2.5 hours, and collect the produced hydrogen gas;

[0044] The liquid products of the reaction are collected and distilled to separate acetaldehyde and acetic acid products, and ethanol is recovered. The recovered ethanol and water are used to prepare an ethanol-water solution, which can be added back to the shell for reuse.

[0045] The liquid product is a mixture of reflux liquid generated by the reaction vapor coming into contact with the condensation jacket in the device housing and the raw material ethanol aqueous solution.

[0046] Beneficial effects:

[0047] (1) High product selectivity and no CO2 emission: The present invention forces the reaction to be carried out in a pure vapor phase environment by a suspended porous catalyst layer, which fundamentally avoids direct contact between the active sites of the catalyst and the liquid reactants, and completely eliminates deep oxidation side reactions such as the breaking of C-C bonds caused by excessive local concentration and limited mass transfer, thereby precisely guiding the reaction path to the generation of acetaldehyde and hydrogen, achieving high selectivity and no CO2 emission.

[0048] (2) Significantly improved hydrogen yield: The porous evaporation layer, with its huge specific surface area and efficient photothermal conversion capability, ensures rapid and continuous evaporation of the ethanol aqueous solution, providing a high-flux of reactant vapors; at the same time, the porous structure of the porous catalyst layer provides sufficient contact area and optimized mass transfer channels for the gas-solid reaction, the loaded metal provides active sites for the reaction, and the photothermal conversion capability of the photothermal conversion material provides the required temperature for the catalytic reaction. The synergistic effect of the two greatly improves the conversion efficiency from reactants to products, achieving a hydrogen yield far exceeding that of traditional fixed-bed reactors.

[0049] (3) The system has high energy efficiency and simple structure: By innovatively integrating the three unit operations of evaporation, conveying and reaction into a simple device that does not require external power, the complex components such as evaporator, preheater and material conveying pump are eliminated, which greatly reduces the complexity of the system and manufacturing cost.

[0050] (4) Green energy and low energy consumption: This invention completely replaces the external heating of traditional thermocatalysis with light energy, and directly uses the photothermal effect to generate heat locally at the reaction site, eliminating the need for a complex external heating system, and realizing the greening and low energy consumption of energy from the source.

[0051] In summary, the ethanol reforming hydrogen production device and method based on photothermal driven vapor phase reaction provided by this invention combines green energy, simple structure, ultra-high efficiency and high selectivity, and solves the three major pain points of traditional technology: "high energy consumption, high complexity and difficult control", showing great potential for industrial application and popularization. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the reaction principle of the ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction in an embodiment of the present invention.

[0053] Figure 2 This is a schematic diagram of the ethanol reforming hydrogen production device and reaction process based on photothermal driven vapor phase reaction in an embodiment of the present invention.

[0054] Figure 3 This is a schematic diagram of the preparation process of the ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction in an embodiment of the present invention; Figure a is a schematic diagram of the preparation process of the porous transport layer and the porous evaporation layer; Figure b is a schematic diagram of the preparation process of the porous catalyst layer.

[0055] Figure 4 The images shown are infrared thermal images, SEM images, TEM images, and EDS images of the ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction in the embodiments of the present invention. In the figure, a is a schematic diagram of the device structure and an infrared thermal image under illumination; b is an SEM image of a porous catalyst layer loaded with Pt and Fe2O3 at different magnifications; and c is a TEM image and an EDS image of a porous catalyst layer loaded with Pt and Fe2O3.

[0056] Figure 5 Figure 1 shows the catalytic performance characterization results of the ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction in the embodiments of the present invention; Figure 2a is a schematic diagram of the ethanol reforming hydrogen production device with fully immersed, semi-immersed and suspended structures; Figure 3b is a comparison of the H2 yield performance of the ethanol reforming catalytic reaction under fully immersed, semi-immersed and suspended structures; Figure 4c is a statistical result of the selectivity of carbon products of the ethanol reforming hydrogen production reaction according to the method described in Example 1; Figure 5d is a result of the stability test of the ethanol reforming hydrogen production reaction according to the method described in Example 1.

[0057] Figure 6This is a comparison chart showing the hydrogen production efficiency of hydrogen production from ethanol reforming according to the method described in Example 1, where Pt and TiO2, Pt and MoS2, and Pt and Fe2O3 are respectively loaded on porous catalyst layers in the embodiments of the present invention.

[0058] In the diagram: 1. Shell, 2. Support, 3. Porous transport layer, 4. Porous evaporation layer, 5. Porous catalyst layer, 6. Condensation jacket, 7. Condensate outlet, 8. Condensate inlet, 9. Liquid inlet, 10. Liquid outlet, 11. Gas outlet. Detailed Implementation

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use.

[0060] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0061] The present invention will be further described below with reference to the embodiments.

[0062] The materials used in the following embodiments are from the following sources:

[0063] FeCl3 was purchased from Shanghai Maclean Biotechnology Co., Ltd.; SiO2 was purchased from Beijing Huawi Ruike Chemical Co., Ltd.; Ti4O7 was purchased from Shanghai Maclean Biotechnology Co., Ltd.; Carbomer was purchased from Shanghai Maclean Biotechnology Co., Ltd.; Urea was purchased from Shanghai Maclean Biotechnology Co., Ltd.; Ethanol was purchased from Hubei Kang Sheng Biotechnology Co., Ltd.; K2PtCl6 was purchased from Beijing Mairuida Technology Co., Ltd.

[0064] Example 1

[0065] This embodiment provides an ethanol reforming hydrogen production apparatus based on a photothermal-driven vapor phase reaction, such as... Figure 1 and Figure 2 As shown, the device includes a shell 1, a support 2, a porous transport layer 3, a porous evaporation layer 4, and a porous catalyst layer 5. The shell 1 and support 2 are made of glass. A liquid inlet 9 is located on the lower middle part of the side of the shell 1 for adding reaction raw materials into the device; a gas outlet 11 is located on the upper part of the shell 1 for collecting the produced hydrogen gas; and a liquid outlet 10 is located on the lower side of the shell 1 for recovering the liquid phase products of the reaction.

[0066] A porous transport layer 3 is placed inside the housing 1, and a porous evaporation layer 4 is placed on top of the porous transport layer 3. A support 2 is located outside the porous transport layer 3 and the porous evaporation layer 4, used to support the porous catalyst layer 5 and suspend it above the porous evaporation layer 4. The porous transport layer 3 and the porous evaporation layer 4 have the same dimensions and materials, including SiO2, Ti4O7, and carbomer. The porous catalyst layer 5 has the same dimensions as the porous transport layer 3 and the porous evaporation layer 4, and its materials include SiO2, Ti4O7, and carbomer, and is loaded with Fe2O3 and Pt.

[0067] Furthermore, in this embodiment, the pores on the porous transport layer 3, porous evaporation layer 4, and porous catalyst layer 5 are arranged in a 6×6 pattern, and the pores are square with a side length of 1 mm.

[0068] The inner side of the housing 1 is also provided with a condensation jacket 6 for injecting condensate into the space between the condensation jacket 6 and the housing 1; the upper part of the condensation jacket 6 is provided with a condensate outlet 7, and the lower part of the condensation jacket is provided with a condensate inlet 8.

[0069] In operation, the ethanol-water solution in shell 1 is first transported to the porous evaporation layer 4 via the porous transport layer 3. Under illumination, the porous evaporation layer 4 efficiently converts the ethanol-water solution into an ethanol-water mixed vapor using the photothermal effect. This mixed vapor then enters the porous catalytic layer 5 to undergo an ethanol reforming reaction. The vapor after reaction is condensed and refluxed, allowing it to re-participate in the transport, evaporation, and catalytic cycle. The liquid phase product is collected, and ethanol, acetaldehyde, and acetic acid can be separated by distillation. The ethanol can be recovered for the preparation of a new ethanol-water solution, while the generated high-purity hydrogen gas can be collected directly.

[0070] Example 2

[0071] This embodiment provides a method for preparing an ethanol reforming hydrogen production device based on a photothermal driven vapor phase reaction as described in Example 1, using Fe2O3 as a metal oxide, such as... Figure 3 As shown, it includes:

[0072] The preparation method of the porous transport layer and the porous evaporation layer includes: using ink direct writing 3D printing technology, using SiO2, Ti4O7 and carbomer as raw materials, printing the porous transport layer substrate and the porous evaporation layer substrate, freeze-drying for 24 h, and further calcining at 1100 ℃ for 4 h in a hydrogen atmosphere to obtain the product.

[0073] The preparation method of the porous catalyst layer includes: using ink direct writing 3D printing technology, using SiO2, Ti4O7 and carbomer as raw materials to print a porous catalyst layer substrate; freeze-drying the porous catalyst layer substrate for 24 h, and further calcining it at 1100℃ for 4 h in a hydrogen atmosphere to obtain the porous catalyst layer material. Fe2O3 nanoparticles are loaded via hydrothermal reaction to obtain a Fe2O3-loaded porous material; the hydrothermal reaction steps include: dissolving FeCl3 and urea in deionized water at a 1:1 ratio to prepare a mixed solution; placing the porous evaporation layer material in the liner of a hydrothermal reactor and adding 10 mL of the mixed solution; placing the liner in the hydrothermal reactor and heating at 100℃ for 24 h; removing the reactor, cooling, and drying in a 60℃ oven for 2 h; and calcining in a muffle furnace at 500℃ for 0.5 h. Further, 0.2 mL of 5 mM K2PtCl6 solution was added dropwise to the Fe2O3-supported porous material, and the mixture was calcined at 350 °C for 2 h in a hydrogen atmosphere to obtain a porous catalyst layer.

[0074] The methods of 3D printing include:

[0075] Ink preparation: Using SiO2 as raw material, prepare 175 mg mL of ink. -1 Add 5 mL of SiO2 aqueous solution, then add 5 mL of 2 wt% carbomer aqueous solution, then add 1.5 g of Ti4O7 powder, and add NaOH aqueous solution to adjust the pH of the solution to neutral to obtain 3D printing ink.

[0076] Printing steps: First, fill a 10 mL special injection syringe with ink and seal it. Install a stainless steel nozzle with an inner diameter of 0.51 mm, and connect the other end of the syringe to a pneumatic controller. Then, fix the syringe to a three-axis robotic arm and start the corresponding computer control program to drive the robotic arm to perform 3D printing. Adjust the ink viscosity to ensure stable extrusion at a printing pressure of 100-200 kPa with a 0.51 mm needle inner diameter, ultimately forming the desired three-dimensional mesh structure.

[0077] like Figure 4As shown in Figure a, the tests indicate that the temperature of the uppermost porous catalyst layer rapidly rises to approximately 383.4 °C under illumination due to direct sunlight and the efficient photothermal conversion capability of the photothermal material Fe2O3, providing the necessary thermal activation energy for the reaction. The porous evaporation layer, whose light source is sunlight passing through the pores of the porous catalyst layer and lacks the photothermal material Fe2O3, maintains a lower temperature, stable at approximately 68.1 °C, effectively ensuring the continuous and stable evaporation of the ethanol-water solution. The gradient distribution and spatial separation of the temperature field experimentally verify the synergistic design concept of "low-temperature evaporation and high-temperature reaction," which is key to achieving high-efficiency and high-selectivity vapor-phase catalytic reforming.

[0078] like Figure 4 SEM images in section b show that Pt and Fe2O3 nanoparticles are uniformly distributed on the surface of the catalyst layer, with a particle size of 10-30 nm. Fe2O3 exhibits strong absorption and photothermal conversion capabilities in the visible light region, creating a high-temperature reaction microenvironment locally within the catalyst layer, acting as the "engine" driving the reaction. Simultaneously, Pt provides stable anchoring sites for the catalytic active sites, effectively inhibiting their migration and aggregation. Pt inhibits C / C bond breaking, thereby precisely guiding the reaction pathway to the dehydrogenation of ethanol to acetaldehyde and hydrogen, achieving CO2-free emissions and high selectivity. Through the synergistic effect of both, the Lewis acid sites on the Fe2O3 surface can also participate in water molecule activation and reactant adsorption, jointly optimizing the catalytic cycle with Pt, achieving simultaneous improvement in reaction kinetics and selectivity.

[0079] like Figure 4 The TEM image of c shows that the lattice spacing of the nanoparticles is 0.271 nm, which coincides with the (104) crystal plane of Fe2O3, and the particle size is about 10 nm, consistent with the SEM results. Figure 4 As shown in the EDS spectrum of c, Pt elements are highly uniformly distributed on the nanoparticles.

[0080] Example 3

[0081] This embodiment provides a method for hydrogen production from ethanol reforming based on photothermal-driven vapor phase reaction, using the ethanol reforming hydrogen production apparatus based on photothermal-driven vapor phase reaction as described in Example 1; the method includes: adding 10 vol% ethanol aqueous solution to the shell until the porous transport layer is below the surface of the ethanol aqueous solution, the porous evaporation layer is placed on the porous transport layer and above the surface of the ethanol aqueous solution, and the porous catalyst layer is suspended in the ethanol aqueous solution.

[0082] Irradiated by a light source, the reaction was carried out for 2 hours. During this period, the generated hydrogen gas was continuously collected and the liquid products of the reaction were collected and distilled to purify acetaldehyde and acetic acid, and ethanol was recovered. The recovered ethanol and water were used to prepare an ethanol-water solution, which could be added back to the shell for reuse.

[0083] Example 4

[0084] This embodiment provides a catalytic performance characterization of an ethanol reforming hydrogen production device based on a photothermal-driven vapor phase reaction.

[0085] like Figure 5 As shown in Figure a, an ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction with a fully immersed, semi-immersed, and suspended structure was constructed to carry out ethanol reforming hydrogen production, with a reaction time of 2 hours.

[0086] The fully immersed structure involves adding a 10 vol% ethanol-water solution to the shell until the porous transport layer, porous evaporation layer, and porous catalyst layer are all below the surface of the ethanol-water solution. A three-layer stacked design is employed, with the porous catalyst layer on top, the porous evaporation layer below it, and the porous transport layer at the bottom. Irradiation with a light source is performed, and the reaction is carried out for 2 hours. During this time, the generated hydrogen gas is continuously collected, and the liquid products of the reaction are collected and distilled to purify acetaldehyde and acetic acid, while ethanol is recovered.

[0087] The semi-immersion structure involves adding a 10 vol% ethanol-water solution to the shell until the porous transport layer and porous evaporation layer are below the surface of the ethanol-water solution, and the porous catalyst layer is above the surface of the ethanol-water solution. A three-layer stacked design is adopted, with the porous catalyst layer on top, the porous evaporation layer below it, and the porous transport layer at the bottom. The reaction is irradiated with a light source and carried out for 2 hours. During this time, the generated hydrogen gas is continuously collected, and the liquid products of the reaction are collected and distilled to purify acetaldehyde and acetic acid, while ethanol is recovered.

[0088] The suspended structure is used for ethanol reforming to produce hydrogen according to the method described in Example 3.

[0089] like Figure 5 As shown in Figure b, Fe₂O₃ is used as the metal oxide. The suspended structure exhibits an extremely high hydrogen yield, reaching 1491 mmol·g⁻¹. -1 ·h -1 The yields were 373 times that of the semi-immersed structure and 994 times that of the fully immersed structure. This result definitively proves that the pure vapor phase reaction environment created by the "suspended" configuration is the key to achieving ultra-high reaction rates.

[0090] like Figure 5 As shown in Figure c, Fe2O3 is used as the metal oxide. Under the suspended structure, the distribution of carbon products (acetaldehyde 68%, acetic acid 8%, CO 8%, CH4 10%, C2 products 3%, C3 products 3%) clearly indicates that the main reaction pathway is selective dehydrogenation of ethanol, with no CO2 generation. This result confirms that Pt inhibits C / C bond breaking, while the photothermal conversion and support effect of Fe2O3 further optimize the reaction microenvironment, jointly achieving a synergistic effect of high acetaldehyde selectivity, no CO2 emissions, and ultra-high hydrogen yield.

[0091] The stability of the suspended structure ethanol reforming hydrogen production device based on photothermal-driven vapor phase reaction was tested. The method included: using the suspended structure ethanol reforming hydrogen production device based on photothermal-driven vapor phase reaction to carry out ethanol reforming hydrogen production reaction, with a single reaction time of 2 hours; after every 2 hours of reaction, gaseous and liquid products were detected, ethanol was recovered, prepared into an ethanol aqueous solution, and added back to the shell for ethanol reforming hydrogen production reaction, repeated 8 times, with a total reaction time of 16 hours.

[0092] like Figure 5 As shown in Figure d, Fe₂O₃ was used as the metal oxide. During the 16-hour experiment, the hydrogen yield of the suspended reaction layer remained stable at approximately 1400 mmol·g⁻¹. -1 ·h -1 The concentration remained high, decreasing by only about 6% from the initial peak. This result confirms that the catalytic system composed of Pt and Fe2O3 in a vapor phase environment possesses excellent structural stability and resistance to deactivation, revealing the enormous practical potential of this technology.

[0093] Example 5

[0094] The ethanol reforming hydrogen production device based on photothermal driven vapor phase reaction was prepared using the method described in Example 2. The difference lies in the use of TiO2 as the metal oxide. The steps of loading Pt and TiO2 onto the porous catalyst layer include: dissolving tetrabutyl titanate and 12 M hydrochloric acid in deionized water at a mass ratio of 1:3 to obtain a mixed solution; placing the porous catalyst layer material in the polytetrafluoroethylene liner of a hydrothermal reactor and adding 10 mL of the mixed solution; placing the liner in the hydrothermal reactor and heating at 160 °C for 24 h; removing the reactor, cooling, and drying in a 60 °C oven for 2 h; calcining in a muffle furnace at 450 °C for 2 h; further adding 0.2 mL of 5 mM K2PtCl6 solution and calcining at high temperature in a hydrogen atmosphere to obtain the final product.

[0095] The method described in Example 2 was used to prepare an ethanol reforming hydrogen production device based on a photothermal-driven vapor phase reaction. The difference was that MoS2 was used as the metal oxide, and the steps of loading Pt and MoS2 onto the porous catalyst layer material included: dissolving thiourea and ammonium heptamolybdate tetrahydrate in deionized water at a mass ratio of 2:1 to obtain a mixed solution; placing the porous catalyst layer material into the polytetrafluoroethylene liner of the hydrothermal reactor and adding 10 mL of the mixed solution; placing the liner into the hydrothermal reactor and heating at 180 °C for 24 h; removing the reactor, cooling, and drying in an oven at 60 °C for 6 h; further adding 0.2 mL of 5 mM K2PtCl6 solution and calcining at high temperature in a hydrogen atmosphere to obtain the final product.

[0096] According to the method described in Example 1, hydrogen production from ethanol was achieved using an apparatus in which Pt and TiO2, Pt and MoS2, and Pt and Fe2O3 were respectively loaded onto a porous catalyst layer. Figure 6 As shown, the hydrogen production efficiency was 187 mmol·g. -1 ·h -1 780 mmol·g -1 ·h -1 1491 mmol·g -1 ·h -1 The results showed that the porous catalyst layer material supported on Pt and Fe2O3 had the best effect on hydrogen production from ethanol reforming.

[0097] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An ethanol reforming hydrogen production apparatus based on photothermal-driven vapor phase reaction, characterized in that, It includes a shell, a support, a porous transport layer, a porous evaporation layer, and a porous catalyst layer; The porous transport layer is placed inside the housing, and the porous evaporation layer is placed on the porous transport layer; The support is located outside the porous transport layer and the porous evaporation layer, and is used to support the porous catalyst layer and suspend the porous catalyst layer above the porous evaporation layer. The porous transport layer, porous evaporation layer and porous catalyst layer are of the same size and each has an array of pores; The porous transport layer is made of SiO2, Ti4O7 and carbomer; the mass ratio of SiO2, Ti4O7 and carbomer is (1-30):(5-30):(1-10). The porous evaporation layer is made of SiO2, Ti4O7 and carbomer; the mass ratio of SiO2, Ti4O7 and carbomer is (1-30):(5-30):(1-10). The porous catalyst layer includes a porous catalyst layer substrate and metal oxides and noble metal elements supported on the porous catalyst layer substrate; the materials of the porous catalyst layer substrate include SiO2, Ti4O7 and carbomer, and the mass ratio of SiO2, Ti4O7 and carbomer is (1-30):(5-30):(1-10).

2. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 1, characterized in that, The metal oxide includes one or more of Fe2O3, TiO2 and MoS2; The noble metal element is Pt.

3. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 1, characterized in that, The preparation method of the porous transport layer and the porous evaporation layer includes: using ink direct writing 3D printing technology, using SiO2, Ti4O7 and carbomer as raw materials, printing the porous transport layer substrate and the porous evaporation layer substrate, and freeze-drying for 12-24 h; calcining the porous transport layer substrate and the porous evaporation layer substrate in a hydrogen atmosphere at 900-1300 ℃ for 2-4 h to obtain the final product.

4. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 2, characterized in that, The method for preparing the porous catalyst layer includes: A porous catalyst layer matrix was printed using ink direct writing 3D printing technology with SiO2, Ti4O7 and carbomer as raw materials. After freeze-drying for 12-24 h, the porous catalyst layer substrate is calcined at 900-1300 °C for 2-4 h in a hydrogen atmosphere to obtain the porous catalyst layer material. The porous catalyst layer material is loaded with metal oxide nanoparticles through a hydrothermal reaction to obtain a porous catalyst layer material loaded with metal oxide. 0.1-1 mL of 1-20 mM K2PtCl6 solution is added dropwise, and the material is calcined at 200-350 ℃ for 1-3 h in a hydrogen atmosphere to obtain the porous catalyst layer.

5. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 1, 3, or 4, characterized in that, The horizontal cross-sectional area of ​​the hole is 0.8-1.2 mm. 2 .

6. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 4, characterized in that, When Fe2O3 is used as the metal oxide, the hydrothermal reaction steps include: FeCl3 and / or its hydrates are dissolved in deionized water at a mass ratio of 1:(0.5-2) to prepare a mixed solution; Add porous catalyst layer material and 5-15 mL of mixed solution to a hydrothermal reactor, and heat at 80-150 °C for 15-30 h to obtain the first hydrothermal reaction product; After the reaction is complete, the first hydrothermal reaction product is dried at 60-100 °C for 1-4 h and calcined at 350-500 °C for 0.5-4 h to obtain the final product.

7. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 4, characterized in that, When TiO2 is used as the metal oxide, the hydrothermal reaction steps include: Tetrabutyl titanate and 10-15 M hydrochloric acid were dissolved in deionized water at a mass ratio of 1:(1-5) to prepare a mixed solution; Add porous catalyst layer material and 5-15 mL of mixed solution to a hydrothermal reactor, and heat at 100-200 °C for 15-30 h to obtain the first hydrothermal reaction product; After the reaction is complete, the first hydrothermal reaction product is dried at 60-100 °C for 1-4 h and calcined at 350-500 °C for 0.5-4 h to obtain the final product.

8. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 4, characterized in that, When MoS2 is used as the metal oxide, the hydrothermal reaction steps include: A mixed solution was prepared by dissolving thiourea and ammonium heptamolybdate and / or their hydrates in deionized water at a mass ratio of 1:(0.5-3). Add porous catalyst layer material and 5-15 mL of mixed solution to a hydrothermal reactor, and heat at 100-250 °C for 15-30 h to obtain the first hydrothermal reaction product; After the reaction is complete, the first hydrothermal reaction product is dried at 60-100 °C for 4-10 h to obtain the final product.

9. The ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction according to claim 1, characterized in that, The shell and bracket are made of glass; The shell is provided with a liquid inlet for adding reaction raw materials into the device; the shell is also provided with a gas outlet for collecting the produced hydrogen gas; the shell is also provided with a liquid outlet for recovering the liquid phase products of the reaction. The inner side of the shell is also provided with a condensation jacket for injecting condensate between the condensation jacket and the shell; The upper part of the condensing jacket is provided with a condensate outlet, and the lower part of the condensing jacket is provided with a condensate inlet.

10. A method for hydrogen production from ethanol reforming based on photothermal-driven vapor-phase reaction, characterized in that, The method uses the ethanol reforming hydrogen production apparatus based on photothermal driven vapor phase reaction as described in any one of claims 1-9; the method includes: Add 10 vol %-90 vol % of an aqueous ethanol solution to the shell until the porous transport layer is below the surface of the aqueous ethanol solution, the porous evaporation layer is placed on the porous transport layer and above the surface of the aqueous ethanol solution, and the porous catalyst layer is suspended above the aqueous ethanol solution. Irradiate with a light source, react for 1.5-2.5 hours, and collect the produced hydrogen gas; The liquid products of the reaction were collected and distilled to separate acetaldehyde and acetic acid products, and ethanol was recovered. The ethanol was then reacted with water to prepare an aqueous ethanol solution, which was then added back into the shell.

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