A solar photocatalysis coupled fuel cell poly-generation system and method

Abstract

The application discloses a solar photocatalysis coupling fuel cell multi-cogeneration system and method, and the system comprises an anode side end plate, an anode plate, an anode side gas diffusion layer, a membrane electrode, a cathode gas diffusion layer, a cathode plate and a cathode side end plate which are sequentially arranged; the membrane electrode comprises an anode catalyst layer, a proton exchange membrane and a cathode catalyst layer which are sequentially arranged; and one side of the anode side end plate is provided with quartz glass. Through the hydrogen overflow effect of the light transmission structure and the catalyst, a "solid-solid" interface direct mass transfer channel from the surface of the photocatalyst to the anode of the fuel cell is constructed, so that the active hydrogen atoms generated by the water photolysis can be captured by the anode of the fuel cell in situ and in real time without forming hydrogen molecules, the energy transmission path is shortened to "light energy -> chemical energy -> electric energy", the total energy efficiency of the system is significantly improved, through the design of the photocatalysis-fuel cell composite catalyst, the system does not need to store and transport intermediate hydrogen during operation. The active hydrogen species is consumed immediately after being generated, no gaseous hydrogen is accumulated in the system, and the safety risk caused by the flammable and explosive characteristics of hydrogen is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of solar hydrogen production technology, specifically relating to a solar photocatalytic coupled fuel cell polygeneration system and method. Background Technology

[0002] Hydrogen, as a high-calorific-value, clean, and pollution-free energy carrier, is an ideal clean energy source. Photocatalytic water splitting for hydrogen production is a promising method of solar energy utilization. Its basic principle is to utilize the property of semiconductor materials to generate charge carriers under light irradiation. These charge carriers migrate to the surface, driving a redox reaction in water to produce hydrogen. Photocatalysis technology can also be used in the environmental field to degrade wastewater containing organic pollutants and co-produce hydrogen.

[0003] Meanwhile, a proton exchange membrane fuel cell (PEMFC) is an electrochemical device that directly and efficiently converts the chemical energy of fuel into electrical energy. Its core component is the membrane electrode assembly, which consists of an anode, a cathode, and a proton exchange membrane sandwiched between them. Hydrogen gas enters the fuel cell through the anode, contacts the catalyst, and then passes through the proton exchange membrane to the cathode to react with oxygen. The basic working principle of a PEMFC is an electrochemical redox reaction; its operation does not involve combustion, resulting in high energy conversion efficiency and the only product being water, making it suitable for co-producing desalinated water.

[0004] Traditionally, combining solar-powered water splitting for hydrogen production with hydrogen fuel cells typically follows a three-stage "photovoltaic-storage-use" model: first, hydrogen is produced by solar-powered water splitting; then, the hydrogen is separated, compressed, and stored; finally, the stored hydrogen is transported to a separate PEM fuel cell unit for power generation. This model is based on mature technology, but its reliance on intermediate hydrogen storage and transportation links increases system complexity and cost.

[0005] The shortcomings and deficiencies of existing technologies are mainly reflected in energy loss, safety risks, and system costs.

[0006] Firstly, there's the issue of energy loss. In traditional "photovoltaic-storage-use" models, hydrogen experiences significant losses during storage and transportation; for example, energy losses during compression and liquefaction can exceed 20% of the total system input. Simultaneously, hydrogen accumulation and blockage effects exist in PEM water electrolyzers, collectively impacting the overall conversion efficiency from solar energy to electricity.

[0007] In terms of safety risks, hydrogen, as a hazardous chemical, presents potential safety hazards during storage and transportation in gaseous form, such as leakage and explosion risks, as well as the aging of hydrogen storage materials, which limits the reliability of the system and the prospects for distributed applications.

[0008] In terms of cost, hydrogen storage containers and transportation processes incur additional costs, with storage and transportation costs accounting for nearly half of the total cost of hydrogen consumption. Furthermore, the separation of hydrogen production and consumption processes makes it difficult to achieve a compact and integrated system design, failing to meet the future energy system's requirements for efficiency, safety, and distributed operation. Summary of the Invention

[0009] To overcome the mass transfer disconnect between traditional solar water splitting (SWS) and proton exchange membrane (PEM) fuel cell power generation systems in existing technologies, the present invention aims to provide a solar photocatalytic coupled fuel cell multi-generation system and method.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A solar photocatalytic coupled fuel cell multi-generation system includes an anode side end plate, an anode plate, a gas diffusion layer on the anode side, a membrane electrode assembly, a cathode gas diffusion layer, a cathode plate, and a cathode side end plate arranged in sequence; the membrane electrode assembly includes an anode catalyst layer, a proton exchange membrane, and a cathode catalyst layer arranged in sequence; quartz glass is disposed on one side of the anode side end plate.

[0011] Furthermore, a serpentine flow channel is provided on the anode plate.

[0012] Furthermore, the anode side end plate is provided with inlet and outlet water pipes that match the flow channels on the anode plate.

[0013] Furthermore, the anode catalyst layer is anatase phase titanium dioxide deposited with platinum oxygen vacancies.

[0014] Furthermore, the mass of platinum is 5% of the mass of titanium dioxide.

[0015] Furthermore, a gas pipe is installed inside the cathode-side end plate.

[0016] Furthermore, the membrane electrode is prepared by spraying a platinum-carbon catalyst onto carbon paper to form a cathode, spraying the catalyst onto polytetrafluoroethylene to form an anode, and then stacking the cathode, proton exchange membrane, and anode in sequence. After hot pressing, the polytetrafluoroethylene is removed to obtain the membrane electrode.

[0017] Furthermore, the cathode catalyst layer is a platinum-carbon catalyst.

[0018] Furthermore, the gas diffusion layer is made of a transparent material.

[0019] A method for combined heat and power generation using a solar photocatalytic coupled fuel cell includes the following steps: Pure water / organic wastewater is introduced to the anode side through the inlet pipe of the anode side end plate, and oxygen is introduced through the gas pipe of the cathode side end plate. Then, sunlight / simulated light source is irradiated onto the anode catalyst layer through the quartz glass light-transmitting window to excite the catalyst on the anode catalyst layer, generate photogenerated electron-hole pairs, and photocatalytically split water to produce active hydrogen species; After dissociation at the platinum site, active hydrogen species migrate to the anode through solid-solid mass transfer channels formed by oxygen vacancies in anatase titanium dioxide, participating in the electrochemical oxidation reaction to generate H2. + and electrons; H + The electrons migrate through the proton exchange membrane to the cathode, where they undergo an oxygen reduction reaction with oxygen and electrons from the external circuit to produce pure water. The electrons then pass through the external circuit to form an electric current, thus generating electricity.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention simplifies the hydrogen mass transfer path, significantly improving system energy efficiency. Through a transparent structure and the hydrogen overflow effect of the catalyst, this invention constructs a direct "solid-solid" interface mass transfer channel from the photocatalyst surface to the fuel cell anode. This allows active hydrogen atoms generated by photocatalytic water splitting to be captured in situ and instantly by the fuel cell anode for power generation without forming hydrogen molecules. The energy transfer path is shortened to "light energy → chemical energy (active hydrogen species) → electrical energy," fundamentally avoiding the significant energy losses caused by hydrogen evolution, gas collection, compression storage, and long-distance transportation. This promises to significantly improve the overall system energy efficiency and overcomes the problem of traditional technologies relying on hydrogen as an intermediate energy carrier, which requires multiple stages of conversion and storage: "light energy → chemical energy (H2) → potential energy (compression storage) → kinetic energy (transportation) → chemical energy (H2) → electrical energy," each accompanied by unavoidable energy losses.

[0021] 2. The system is highly integrated and multifunctional, with broad application prospects. This invention optimizes the mass transfer process, highly integrating hydrogen production and power generation units into a compact modular reactor with a simple structure. This integrated design facilitates modular scale-up or distributed deployment, making it ideal for off-grid, remote area power supply, or emergency power generation. Simultaneously, the system can co-produce freshwater while generating electricity, and the TiO2-based photocatalyst itself possesses the ability to photodegrade organic pollutants. Therefore, it can be extended to a coupled application of "power generation-water purification," achieving multiple production processes and further improving the system's resource utilization efficiency and practicality.

[0022] Furthermore, a serpentine flow channel is provided on the anode plate to evenly distribute water to the anode side, providing reactants for the photocatalytic hydrogen production process and increasing the gas contact area.

[0023] Further, the anode-side end plate is provided with a water inlet and outlet pipeline, which matches the flow channel on the anode plate to realize water inlet and outlet on the anode side, and can also input wastewater containing organic pollutants for photocatalytic degradation.

[0024] Further, the material of the gas diffusion layer is a transparent material or a material transparent to part of the usable spectrum, so as to ensure that the incident light from the anode-side end plate can directly irradiate the surface of the anode catalyst.

[0025] The hydrogen storage and transportation link is fundamentally eliminated, with both safety and economic performance. Through the design of the photocatalysis-fuel cell composite catalyst of the present invention, the system does not require intermediate hydrogen storage and transportation during operation. Active hydrogen species are consumed immediately after generation, and no gaseous hydrogen accumulates in the system, which greatly reduces the safety risk caused by the flammable and explosive characteristics of hydrogen, and at the same time can reduce the operation and maintenance cost of the system, improve the economy of poly-generation, and overcome the problems that high-pressure hydrogen storage or low-temperature liquid hydrogen storage and transportation in the traditional mode are not only costly, but also have safety hazards such as leakage and explosion. Brief Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the solar photocatalysis coupled fuel cell poly-generation system of the present invention; Figure 2 is a cross-sectional view of the solar photocatalysis coupled fuel cell poly-generation system of the present invention; Figure 3 is a schematic plan view of the anode plate; In the drawings, 1 is the anode-side end plate, 2 is the anode plate, 3 is the gas diffusion layer on the anode side, 4 is the anode catalyst layer, 5 is the proton exchange membrane, 6 is the cathode catalyst layer, 7 is the cathode gas diffusion layer, 8 is the cathode plate, 9 is the cathode-side end plate, and 10 is the flow channel. Detailed Description of the Embodiments

[0027] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant accompanying drawings. The preferred embodiments of the present invention are given in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0028] In addition, when an element in the present invention is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may be a middle element present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a middle element present at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

[0029] See Figure 1 and Figure 2 The present invention provides a solar photocatalytic coupled fuel cell polygeneration system, which solves the mass transfer disconnect problem between traditional solar water splitting (SWS) hydrogen production and proton exchange membrane (PEM) fuel cell power generation systems. The solar photocatalytic coupled fuel cell polygeneration system includes, from left to right, an anode side end plate 1, an anode plate 2, an anode side gas diffusion layer 3, an anode catalyst layer 4, a cathode catalyst layer 6, a cathode gas diffusion layer 7, a cathode plate 8, and a cathode side end plate 9.

[0030] The main function of the anode-side end plate 1 is to provide uniform mechanical clamping force for the entire device, ensuring tight contact between internal components, preventing reactant gas leakage, and supporting the stacked structure. On the left side of the anode-side end plate 1, there is a frustum-shaped opening that houses a piece of quartz glass matching the size of the membrane electrode assembly (MEA) of the fuel cell, allowing sunlight to pass through the anode-side end plate 1 and irradiate the fuel cell surface. The MEA has a maximum area of ​​2cm × 2cm and uses a dual-electrode structure, comprising an anode catalyst layer 4, a proton exchange membrane 5, and a cathode catalyst layer 6 arranged sequentially.

[0031] See Figure 3 The anode plate 2 is made of titanium alloy, and a serpentine flow channel 10 is engraved in the center of the anode plate 2. The flow channel is used to evenly distribute water to the anode side, providing reactants for the photocatalytic hydrogen production process and increasing the gas contact area. It can be replaced with a hollow electrode plate. One end of the electrode plate of the anode plate 2 extends outward, which plays a role in conducting fuel cell current.

[0032] The anode side end plate 1 is designed with inlet and outlet water pipes that match the flow channel 10 on the anode plate 2 to realize water inlet and outlet on the anode side, and can also input wastewater containing organic pollutants for photocatalytic degradation.

[0033] Specifically, the outermost layer of the multi-generation system is a hollow stainless steel structure containing inlet and outlet water pipes and a gas passage. A 2×2cm quartz glass is embedded in the center, allowing for future component replacement. The components of the multi-generation system are connected by resin gaskets and secured with nine screws.

[0034] The membrane electrode assembly (MEA) of a fuel cell is the site of electrochemical reactions within the fuel cell. The MEA was prepared using a DuPont Nafion-117 perfluorosulfonic acid proton exchange membrane and Toray TGPH060T hydrophobic carbon paper. A total of three MEAs were prepared, with the negative electrode using a 20 wt% platinum-carbon catalyst (an existing catalyst) at a concentration of 0.5 g / cm³. 2 The load capacity is 4cm2 Above. The anodes were prepared by ball milling, with 3mm zirconia beads added at a 50% mass ratio. The mixture was milled five times at 300 rpm for 30 minutes each time to prepare TiO2-Pt / C, TiO2-O, and Pt / TiO2-O, maintaining a loading of 0.5 g / cm³. 2 Consistent. The loading method was spray gun coating. Carbon paper was used on the cathode, and polytetrafluoroethylene (PTFE) was used to coat the anode. The coating was hot-pressed at 115°C for 75 seconds using a hot press. After cooling, the PTFE on the anode side was removed with tweezers to obtain the membrane electrode.

[0035] The gas diffusion layer 3 on the anode side is made of a transparent material or a material that is transparent to a portion of the available spectrum, so as to ensure that incident light from the anode side end plate 1 can directly irradiate the surface of the anode catalyst, while having good electrical conductivity and hydrophobicity.

[0036] The anode catalyst layer 4 is crucial for the chemical reaction. This layer consists of a semiconductor photocatalyst supported on a conductive carrier (such as titanium dioxide and a carbon support). This invention uses anatase-phase titanium dioxide with oxygen vacancies prepared in a reducing atmosphere, and then photodeposits 5 wt% platinum (by weight of titanium dioxide) to prepare a PD-Pt / TiO2-O composite catalyst, i.e., a semiconductor photocatalyst (where PD represents photo-deposition). When light irradiates the surface of the semiconductor photocatalyst, active hydrogen species, rather than hydrogen gas, are generated in situ through a hydrogen spillover effect and transferred in situ to the proton exchange membrane 5 for the next reaction.

[0037] The function of the proton exchange membrane 5 is to allow only the protons generated by the reaction to pass through to the cathode, while isolating hydrogen and oxygen, and acting as an electronic insulator to force electrons to do work through the external circuit.

[0038] The cathode catalyst layer 6 is composed of a typical fuel cell cathode catalyst (such as platinum carbon).

[0039] The cathode gas diffusion layer 7 does not need to meet the light transmittance requirements and is composed of a typical fuel cell gas diffusion layer (such as carbon paper).

[0040] The structure of the cathode plate 8 is the same as that of the anode plate 2.

[0041] The cathode side plate 9 is provided with a gas pipe inside, which is used to introduce oxygen and discharge the remaining gas and water vapor generated by the fuel cell.

[0042] In this combined production system, it is necessary to ensure that the surface of the anode catalyst can be exposed to external light to drive the photocatalytic reaction. Therefore, the use of quartz glass instead of the traditional opaque endplate is essential to ensure that visible and near-ultraviolet light in the solar spectrum can efficiently penetrate and excite the photocatalyst (wide-bandgap TiO2). Quartz glass has higher transmittance than ordinary glass, especially in the ultraviolet region, which is necessary for the selection of wide-bandgap TiO2 in this invention.

[0043] In conventional PEM water electrolyzers, the catalyst layer (CL) is located between the gas diffusion layer (GDL) and the proton exchange membrane. The GDL is typically made of carbon fiber paper or carbon cloth, and its main functions are to conduct electrons, transport the reactant water, and expel the products hydrogen and oxygen. However, for the purposes of this invention, the presence of the conventional opaque GDL poses several obstacles. First, it acts as an opaque physical barrier, blocking external light sources from reaching the photocatalyst located beneath it. Second, the porous structure of the GDL hinders the efficient transport of photogenerated carriers to the catalyst surface. Therefore, in this invention, a transparent gas diffusion layer is employed to prioritize ensuring in-situ hydrogen transfer.

[0044] On the anode side (i.e., the right side) of the cogeneration system, this invention employs a replaceable and removable light window design, with quartz glass meeting the requirements. Other components of the cogeneration system are also removable, such as using electrode plates with flow channels. Considering that the electrode plates significantly reduce the light-exposed area of ​​the anode photocatalyst, the flow channels can be reduced or removed directly to achieve maximum usability.

[0045] See Figure 1 Mass transfer process design is one of the core driving forces of this invention. This invention employs hydrogen overflow as the dominant process in hydrogen mass transfer. This mechanism describes the dissociation of hydrogen molecules (H2) into adsorbed hydrogen atoms (H2) on the surface of a metal catalyst (such as platinum, Pt). * This process involves the highly reactive H atoms migrating to the surface of a nearby non-metallic support (such as titanium dioxide, TiO2). In this system, it is hoped that the H· generated on the photocatalyst surface will rapidly dissociate into H on the attached Pt nanoparticles. These H atoms... * Subsequently, thanks to the migration pathways provided by the abundant defects (mainly oxygen vacancies) in the TiO2 lattice, the electrons escape from the photocatalyst surface and are efficiently captured by the adjacent PEMFC anode, immediately participating in the electrochemical oxidation reaction. This direct electron / proton transfer at the solid-solid interface is theoretically far more efficient than the traditional liquid-gas-solid transfer pathway because it avoids the accumulation and blockage of bubbles on the electrode surface, which is one of the main reasons for the performance degradation of PEM water electrolyzers.

[0046] This invention achieves the mass transfer process of in-situ photocatalytic hydrogen transfer through a solar photocatalytic coupled fuel cell polygeneration system and catalyst design. Mass transfer is optimized through macroscopic and microscopic design, shortening the energy transfer path and combining two promising energy technologies to create a technological foundation for future energy needs.

[0047] This invention selects a platinum-carbon system as the substrate for the anode catalyst 4 of PEMFC. Pt is one of the most efficient hydrogen molecule dissociation catalysts known. On its surface, hydrogen molecules (H2) readily dissociate into highly active adsorbed hydrogen atoms (H2). * This is the first step in initiating hydrogen overflow and a prerequisite for the smooth progress of subsequent processes. Secondly, in the photocatalytic system, Pt can also act as a cocatalyst. TiO2 absorbs photons and generates electron-hole pairs, but these carriers recombine easily, leading to low quantum efficiency. Pt nanoparticles can effectively capture photogenerated electrons in the conduction band of TiO2, suppressing electron-hole recombination and thus improving quantum efficiency.

[0048] This invention uses titanium dioxide as a photocatalytic substrate and prepares oxygen vacancies on its surface through a reducing atmosphere. Oxygen vacancies can introduce defect energy levels into the band gap, broadening the absorption range of TiO2 for visible light and enabling it to utilize a wider solar spectrum for reactions. Furthermore, these defects can act as efficient electron traps, promoting the separation of photogenerated electrons and holes, further improving quantum efficiency. In this invention, the most important function of oxygen vacancies is to provide migration channels for hydrogen spillover. Hydrogen spillover is essentially the process of H migrating from Pt to the TiO2 surface and being adsorbed, a process that requires overcoming a certain energy barrier. The oxygen vacancies and the surrounding Ti... 3+ Ions can serve as adsorption sites for H, significantly reducing the energy barrier for H migration from Pt to the TiO2 surface. Furthermore, oxygen vacancies enhance the interaction between Pt and TiO2, preventing the aggregation of Pt nanoparticles and thus improving the long-term stability of the catalyst.

[0049] This invention designs two sets of catalysts and tests the performance of each catalyst.

[0050] First, TiO2-Pt / C composite materials were prepared by ball milling. 500 mg of P25 and 20 wt% commercial platinum-carbon catalyst (60% water content) were weighed out and ball-milled for 6 × 30 min using 3 mm zirconia grinding beads to obtain a physically mixed sample, which was black in color.

[0051] Using 2g of P25, reduction was performed at 500℃ under a reducing atmosphere (5% H2, 95% Ar by volume) to prepare oxygen vacancies on the P25 surface, yielding 2000mg of oxygen-vacancy titanium dioxide sample, which was white. 400mg of the oxygen-vacancy titanium dioxide sample was weighed and added to 2.655ml of H2PtCl6·6H2O solution (20mg / ml), along with 25ml each of anhydrous ethanol and ultrapure water as dispersion systems. The mixture was ultrasonically dispersed for 30min, and argon gas was introduced for 10min to purge air. Subsequently, the mixture was continuously irradiated under a xenon lamp for 1h, resulting in the photodeposition of 5 wt% Pt loading on the TiO2 surface, yielding a gray-black PD-Pt / TiO2-O catalyst.

[0052] The following is a test and analysis of the catalyst performance.

[0053] 20 mg of a ball-milled mixture of TiO2-Pt / C and PD-Pt / TiO2-O was added to 27 ml of pure water and 3 ml of triethylamine. Hydrogen production was tested under constant power (5 W) and wavelength (360 nm) light source irradiation. Gas chromatography sampling was performed every 1 hour, and the hydrogen production rate was compared with a standard curve to obtain the yield. The measured hydrogen production rate of TiO2-Pt / C was 9309 µmol / g. -1 h -1 The hydrogen production rate of PD-Pt / TiO2-O is 15310 µmol g. -1 h -1 This indicates that the photodeposition of Pt and the preparation of oxygen vacancies significantly improve the photocatalytic hydrogen production performance of PD-Pt / TiO2-O.

[0054] The core improvement of this solar photocatalytic coupled fuel cell polygeneration system lies in removing the gas diffusion layer on the anode side of a traditional PEMFC and installing quartz glass as a light-transmitting window at the anode end plate. This allows the light source to directly irradiate the anode catalyst layer to excite the photocatalytic reaction, while simultaneously creating the shortest path for hydrogen overflow. This polygeneration system can achieve power generation without hydrogen participation and co-production of fresh water, realizing a one-step hydrogen production, storage, and utilization driven by high solar energy efficiency. Furthermore, it innovatively uses PD-Pt / TiO2-O in the photocatalytic hydrogen production coupled with a proton exchange membrane fuel cell composite system to achieve highly efficient interfacial hydrogen overflow.

[0055] The solar photocatalytic coupled fuel cell polygeneration method of the present invention, as described above, includes the following steps: Step 1: Assemble the anode side end plate 1, anode plate 2, anode side gas diffusion layer 3, anode catalyst layer 4, proton exchange membrane 5, cathode catalyst layer 6, cathode gas diffusion layer 7, cathode plate 8 and cathode side end plate 9 in sequence, and tighten the screws with the preset torque to ensure a leak-free seal. Step 2: Pure water / organic wastewater is introduced into the anode side through the water inlet pipe of the anode side end plate 1, and the water inlet flow rate is controlled at 0.10 mL / min. Oxygen is introduced through the gas pipe of the cathode side end plate 9, and the oxygenation rate is controlled at 0.50 mL / min. Step 3: Photocatalytic excitation. Sunlight / simulated light source (wavelength 360 nm, power 5 W) is irradiated onto the anode catalyst layer 4 through a quartz glass window to excite the PD-Pt / TiO2-O catalyst to generate photogenerated electron-hole pairs, which then photocatalytically split water to produce active hydrogen species (H2O). * ); Step 4: In-situ hydrogen mass transfer, H * After dissociation at the Pt sites, the Pt particles migrate to the PEMFC anode via solid-solid mass transfer channels formed by TiO2 oxygen vacancies, directly participating in the electrochemical oxidation reaction to generate H2. + and electrons; Step 5: Electrochemical reaction in the fuel cell, H + The electrons migrate through the proton exchange membrane to the cathode, where they undergo an oxygen reduction reaction with oxygen and electrons from the external circuit to produce pure water. The electrons then generate electricity by forming an electric current through the external circuit. Step 6: Collect the pure water generated at the cathode and test the wastewater discharged from the anode side to achieve degradation of organic pollutants and recovery of products; Step 7: Replace the catalyst / quartz glass according to operational requirements to ensure long-term stable operation of the system.

[0056] This invention, based on the principle of photocatalytic hydrogen production, designs a system for the production, storage, and transportation of hydrogen. The essence of this process is the transfer of hydrogen species. It couples solar-powered water splitting for hydrogen production with a PEM fuel cell to create a multi-generation system. This system uses solar energy to directly convert hydrogen ions in water into active hydrogen. Subsequently, the active hydrogen is transferred to the anode of the PEM fuel cell via a solid-solid pathway for fuel cell power generation, eliminating the need for hydrogen transportation and storage. This achieves an organic integration of upstream, midstream, and downstream hydrogen energy, providing a new pathway for the utilization of solar energy and a new approach for the utilization of hydrogen energy.

[0057] The core innovation of this invention lies in breaking through the traditional three-stage energy conversion paradigm of "photocatalytic water splitting for hydrogen production—hydrogen storage—fuel cell power generation," and for the first time constructing and verifying a photocatalytic-PEMFC direct-coupled polygeneration system based on the in-situ hydrogen overflow effect. Unlike existing technologies that often treat photocatalysis and fuel cells as independent units or simply connect them via external circuits, this system, through integrated design and catalyst interface engineering, achieves active hydrogen species (H... * In-situ transfer from the photocatalyst surface to the solid-solid interface of the fuel cell anode has the following advantages: (1) At the structural level of the polygeneration system, the traditional opaque gas diffusion layer is innovatively removed and replaced with a transparent gas diffusion layer and a quartz window is introduced to open the three-phase interface of light-catalyst-electrolyte, so that light can directly excite the catalyst on the anode side. (2) At the catalyst level, a composite structure of TiO2 loaded with Pt enriched with oxygen vacancies was designed. The oxygen vacancies significantly promote the separation of photogenerated carriers and construct a "high-speed channel" for hydrogen overflow, while Pt serves as both a photocatalytic co-catalyst and a dual-functional site for hydrogen dissociation / electrochemical oxidation. This design avoids the energy loss and engineering complexity of hydrogen evolution, collection, and transportation in traditional pathways, eliminates the bubble blockage problem in principle, and provides a new approach for efficient, compact, and integrated conversion of solar energy to electrical energy, demonstrating significant system integration innovation and interfacial process control innovation.

[0058] The photocatalytic-PEM fuel cell integrated multigeneration system based on the hydrogen spillover effect proposed in this invention shows unique application prospects in the field of renewable energy conversion and utilization. Its core advantage lies in the direct coupling of solar-driven water splitting and in-situ fuel cell power generation through the design of an oxygen vacancy-modified TiO2 / Pt catalyst and innovative reactor structure, avoiding the energy losses and system complexity of the traditional multi-stage "hydrogen production-storage-power generation" process. This mechanism not only contributes to the development of efficient, low-platinum, and scalable photocatalytic water splitting hydrogen production technology but also provides a new paradigm for distributed clean energy systems.

[0059] In terms of environmental benefits, the system emits no carbon throughout its entire lifecycle and possesses an extremely low potential carbon footprint, aligning with the goals of green hydrogen development and carbon neutrality. In terms of application scenarios, its highly integrated nature and lack of external hydrogen storage units make it particularly suitable for scenarios with stringent safety and reliability requirements, such as off-grid communication base stations, microgrids in remote areas, and emergency power supplies. Simultaneously, the TiO2-based photocatalyst also possesses pollutant degradation capabilities, extending to multifunctional energy-environment coupling systems that synergistically integrate hydrogen production and water purification. Although currently limited by the efficiency of photocatalytic solar-hydrogen conversion, its in-depth exploration of the mass transfer process based on the photocatalytic hydrogen overflow effect provides an important scientific foundation and technological pathway for overcoming efficiency bottlenecks and developing novel integrated energy devices.

[0060] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0061] 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 invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A solar photocatalytic coupled fuel cell multi-generation system, characterized in that, It includes an anode side end plate (1), an anode plate (2), a gas diffusion layer (3) on the anode side, a membrane electrode, a cathode gas diffusion layer (7), a cathode plate (8) and a cathode side end plate (9) arranged in sequence; the membrane electrode includes an anode catalyst layer (4), a proton exchange membrane (5) and a cathode catalyst layer (6) arranged in sequence; quartz glass is provided on one side of the anode side end plate (1).

2. The solar photocatalytic coupled fuel cell multi-generation system according to claim 1, characterized in that, A serpentine flow channel is provided on the anode plate (2).

3. The solar photocatalytic coupled fuel cell multi-generation system according to claim 2, characterized in that, The anode side end plate (1) is provided with inlet and outlet water pipes that match the flow channels on the anode plate (2).

4. The solar photocatalytic coupled fuel cell multi-generation system according to claim 1, characterized in that, The anode catalyst layer (4) is anatase phase titanium dioxide with platinum oxygen vacancies deposited on it.

5. The solar photocatalytic coupled fuel cell multi-generation system according to claim 4, characterized in that, The mass of platinum is 5% of the mass of titanium dioxide.

6. The solar photocatalytic coupled fuel cell multi-generation system according to claim 1, characterized in that, A gas pipe is installed inside the cathode side end plate (9).

7. The solar photocatalytic coupled fuel cell multi-generation system according to claim 1, characterized in that, The membrane electrode is prepared by spraying a platinum-carbon catalyst onto carbon paper to form a cathode, spraying the catalyst onto polytetrafluoroethylene to form an anode, and then stacking the cathode, proton exchange membrane, and anode in sequence. After hot pressing, the polytetrafluoroethylene is removed to obtain the membrane electrode.

8. The solar photocatalytic coupled fuel cell multi-generation system according to claim 1, characterized in that, The cathode catalyst layer is a platinum-carbon catalyst.

9. The solar photocatalytic coupled fuel cell multi-generation system according to claim 1, characterized in that, The gas diffusion layer (3) is made of a transparent material.

10. A method for combined solar photocatalytic coupling fuel cell production based on the system described in claim 4, characterized in that, Includes the following steps: Pure water / organic wastewater is introduced to the anode side through the water inlet pipe of the anode side end plate (1), and oxygen is introduced through the gas pipe of the cathode side end plate (9). Then, sunlight / simulated light source is irradiated onto the anode catalyst layer (4) through the quartz glass light-transmitting window to excite the catalyst on the anode catalyst layer (4), generate photogenerated electron-hole pairs, and photolyze water to produce active hydrogen species; After dissociation at the platinum site, active hydrogen species migrate to the anode through solid-solid mass transfer channels formed by oxygen vacancies in anatase titanium dioxide, participating in the electrochemical oxidation reaction to generate H2. + and electrons; H + The protons migrate through the proton exchange membrane (5) to the cathode, where they undergo an oxygen reduction reaction with oxygen and electrons from the external circuit to generate pure water. The electrons then pass through the external circuit to form an electric current, thus generating electricity.

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