High-temperature proton membrane fuel cell device and method for producing ammonia and generating power through NO reduction

Abstract

The invention discloses a high-temperature proton membrane fuel cell device and method for producing ammonia and generating power through NO reduction. The device comprises an anode, a cathode, a proton exchange membrane, a gas diffusion layer and an external circuit. The anode is configured to receive H2 and perform oxidation reaction; the cathode is configured to receive NO gas and carry out reduction reaction, and the NO reduction reaction path is regulated and controlled through a cathode catalyst; the proton exchange membrane is a high-temperature proton exchange membrane, and the operating temperature range is 100-200 DEG C; the cathode catalyst is configured to regulate and control the NO reduction path in the applied potential range, so that N2 or N2O is preferentially generated in the potential interval of 0.9 V to 0.2 V, and NH3 is generated in the potential interval of 0.2 V to 0 V. According to the method, the problem of catalyst poisoning at low temperature is avoided, harmful NO pollutants can be converted into high-added-value chemicals, and the problem of resource waste is solved; nO is treated while power is generated, the overall energy utilization efficiency is improved, secondary pollution is reduced, the operation cost is reduced, and remarkable environmental and economic benefits are achieved.

Description

Technical Field

[0001] This invention relates to nitrogen oxides (NOx) x In the field of pollutant treatment technology, this invention relates in particular to a high-temperature proton membrane fuel cell device and method for generating electricity by reducing NO to ammonia. Background Technology

[0002] In the existing field of environmental pollution control, one aspect involves NO. x Pollutant treatment. Existing NO pollutant treatment technologies typically employ selective catalytic reduction (SCR). SCR technology combines a catalyst (such as V2O5-WO3 / TiO2) with a reducing agent (such as NH3 or urea) to convert NO into harmless N2 through a catalytic reaction. Its main working principle is that NO reacts with the reducing agent on the catalyst surface to undergo a redox reaction, producing N2 and H2O.

[0003] In the field of existing energy conversion, one aspect involves low-temperature proton exchange membrane fuel cells (LT-PEMFC). Current LT-PEMFC technology typically uses Pt-based catalysts to process hydrogen or methanol fuel, generating electricity through an electrochemical reaction, but usually does not involve NO reduction. Its main working principle is as follows: hydrogen or methanol fuel decomposes into protons and electrons at the anode; protons are transferred through the membrane, and electrons are transferred through the circuit; both combine with oxygen at the cathode to generate water and release electrical energy.

[0004] However, the aforementioned existing technologies all have their own shortcomings. For example, SCR technology only converts NO to N2, performing a simple detoxification process, thus leading to resource waste and failing to achieve high-value utilization of NO (such as producing NH3 or generating electricity). Furthermore, SCR technology requires the addition of a reducing agent, increasing operating costs and potentially causing secondary pollution. As for LT-PEMFC technology, its low operating temperature (typically <100℃) makes it unsuitable for NO reduction reactions, resulting in catalyst poisoning, low reaction efficiency, and an inability to control the reaction pathway to selectively generate NH3. Therefore, it is necessary to provide a high-temperature proton exchange membrane fuel cell device and method for NO reduction to produce ammonia and generate electricity to overcome these shortcomings. Summary of the Invention

[0005] The purpose of this invention is to provide a high-temperature proton exchange membrane fuel cell device and method for NO reduction to produce ammonia and generate electricity, aiming to solve the problems of high energy consumption, low product value, and poor flexibility. By selecting a specific catalyst to control the reaction path, NO is reduced to N2, N2O or NH3 and generated electricity simultaneously, which is suitable for industrial waste gas treatment, clean energy production and other scenarios.

[0006] To achieve the above objectives, the present invention provides a high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity, comprising: The anode is configured to receive H2 and undergo an oxidation reaction, producing protons and electrons. The cathode is configured to receive NO gas and carry out a reduction reaction, and the NO reduction reaction pathway is controlled by the cathode catalyst to selectively generate N2, N2O or NH3. A proton exchange membrane is disposed between the anode and the cathode and configured to migrate the protons generated by the anode to the cathode; the proton exchange membrane is a high-temperature proton exchange membrane with an operating temperature range of 100℃-200℃; Two gas diffusion layers are respectively disposed on the outside of the anode and the cathode; An external circuit is connected to the anode and the cathode and configured to transfer the electrons generated by the anode to the cathode to generate electrical energy; The cathode catalyst comprises a platinum group metal or an alloy thereof, configured to regulate the NO reduction pathway within an applied potential range, such that N2 or N2O is preferentially generated in the potential range of 0.9 V-0.2 V, and NH3 is generated in the potential range of 0.2 V-0 V.

[0007] In a preferred embodiment, the cathode catalyst is selected from Pt / C, Pd / C, Ru / C, PtPd / C, PtRu / C, PtCo / C, or PtCu / C, and the loading is 0.2 mg. M ·cm -2 -2 mg M ·cm -2 .

[0008] In a preferred embodiment, the cathode catalyst is PtPd / C with a loading of 1 mg. PtPd ·cm -2 .

[0009] In a preferred embodiment, the catalyst configured at the anode is Pt / C with a loading of 1 mg. Pt ·cm -2 .

[0010] In a preferred embodiment, it further includes an H2O evaporator configured to supply water vapor to the cathode to regulate the reaction environment of the cathode, wherein the H2O flow rate is controlled at 0 ml / min-0.22 ml / min.

[0011] In a preferred embodiment, the flow rate of H2 received by the anode is 10 sccm-180 sccm, and the flow rate of NO gas received by the cathode is 10 sccm-180 sccm.

[0012] In a preferred embodiment, the flow rate of H2 received by the anode is 120 sccm, and the flow rate of NO gas received by the cathode is 120 sccm.

[0013] In a preferred embodiment, the proton exchange membrane is a polybenzimidazole membrane, and the operating temperature is 160°C.

[0014] The present invention also provides a method for generating electricity by reducing NO to produce ammonia, which is implemented by a high-temperature proton membrane fuel cell device for generating electricity by reducing NO to produce ammonia as described in any of the above embodiments, and includes the following steps: Supply H2 to the anode; NO gas is supplied to the cathode; At the operating temperature of the proton exchange membrane, a potential in the range of 0.9 V to 0 V is applied to regulate the NO reduction reaction pathway to selectively generate N2, N2O or NH3; Electrical energy is collected through external circuitry.

[0015] In a preferred embodiment, NH3 is generated when the applied potential is in the range of 0.2 V to 0 V.

[0016] The high-temperature proton membrane fuel cell device and method for NO reduction to produce ammonia and generate electricity provided by this invention have the following beneficial effects: (1) The proton exchange membrane operates under high temperature conditions (100℃-200℃), which improves the proton conductivity and catalyst activity, avoids the problem of catalyst poisoning at low temperature, thereby improving the catalyst's resistance to poisoning and the reaction rate, and extending the life of the device. (2) The cathode catalyst, through its electrocatalytic properties, changes the reaction pathway of NO reduction under the potential regulation applied by the external circuit: at higher potentials (0.9 V-0.2 V), NO mainly generates N2 or N2O through deoxygenation or coupling pathways; at lower potentials (0.2 V-0 V), NO gains more electrons and protons and generates NH3 through hydrogenation pathway; thus, harmful NO pollutants are converted into high-value-added chemicals (such as NH3), realizing "turning waste into treasure", solving the resource waste problem of existing technologies that only detoxify NO into N2; at the same time, it can adapt to different needs (such as priority power generation or ammonia production), enhancing the applicability and flexibility of the device; (3) Hydrogen is oxidized at the anode to generate protons and electrons. Electrons are transferred to the cathode through an external circuit to generate electrical energy. Protons migrate to the cathode through the proton exchange membrane and undergo a reduction reaction with NO and electrons to realize NO conversion and synchronous power generation. NO is processed while generating electricity, which improves the overall energy utilization efficiency, reduces external energy consumption, reduces secondary pollution, and reduces operating costs, resulting in significant environmental and economic benefits. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of a high-temperature proton membrane fuel cell device for NO reduction and ammonia generation provided by the present invention; Figure 2 for Figure 1 The polarization curves of different cathode catalysts in the HT-PEMFC device are shown. Figure 3 for Figure 1 The graph shows a comparison of NH3 yields for different catalysts (Pt / C, Pd / C, PtPd / C) in the HT-PEMFC unit. Figure 4 for Figure 1 The HT-PEMFC device shown contains a 40% PtPd / C catalyst at 0.2 mg. PtPd ·cm -2 -2 mg PtPd ·cm -2 Optimization curve for load capacity; Figure 5 for Figure 1 The optimized flow rate curve of the H2O evaporator in the HT-PEMFC device is shown in the range of 0 ml / min to 0.22 ml / min. Figure 6 for Figure 1 The optimized flow curve of H2 in the HT-PEMFC device at velocities of 10 sccm-180 sccm is shown. Figure 7 for Figure 1 The optimized flow curves of NO gas in the HT-PEMFC device at flow rates of 10 sccm-180 sccm are shown. Detailed Implementation

[0019] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are merely for explaining the invention and are not intended to limit the invention.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] In an embodiment of the present invention, a high-temperature proton exchange membrane fuel cell device for NO reduction to produce ammonia and generate electricity is provided. This device reduces NO to high-value products (such as ammonia, NH3) while simultaneously generating electricity, and is suitable for scenarios such as industrial waste gas treatment and clean energy production. The high-temperature proton exchange membrane fuel cell is referred to as HT-PEMFC (High Temperature Proton Exchange Membrane Fuel Cell).

[0023] Combination Figure 1 As shown, the high-temperature proton exchange membrane fuel cell device for NO reduction to produce ammonia and generate electricity includes: an anode, a cathode, a proton exchange membrane (PEM), two gas diffusion layers (GDL), an H2O evaporator, and external circuitry. The anode and cathode are located on opposite sides of the proton exchange membrane, and the two gas diffusion layers are located on the outer sides of the anode and cathode, respectively.

[0024] The anode is configured to receive H2 and undergo an oxidation reaction to produce protons (H2O). + ) and electrons (e - The anode surface includes an anode catalyst layer (anode CL (Catalyst Layer)) that provides a reaction site for the anode catalyst. In this embodiment, the anode catalyst is Pt / C (such as commercial 40% Pt / C) with a loading of 1 mg. Pt ·cm -2 The subscript Pt indicates that the load is a load of metallic Pt, and the same applies below.

[0025] The anode is connected to a hydrogen inlet. H2 entering through this inlet diffuses evenly throughout the anode core (CL) via a gas diffusion layer (GDL) on the same side, ensuring an adequate supply of reactants. The flow rate of H2 received at the anode side is 10 sccm–180 sccm. Figure 6As shown, to ensure high peak power density and high NH3 yield, the flow rate of H2 received at the anode is preferably 120 sccm to optimize gas mass transfer and reactant supply, and to avoid insufficient reaction due to too low a flow rate or waste of resources and reduced efficiency due to too high a flow rate.

[0026] The cathode is configured to receive NO gas and perform a reduction reaction. The cathode surface includes a cathode catalyst layer (cathode CL) that provides a reaction site for the cathode catalyst. The cathode is connected to an NO inlet, through which NO gas enters and diffuses uniformly throughout the entire cathode CL via a gas diffusion layer (GDL) on the same side, ensuring an adequate supply of reactants. The flow rate of NO gas received at the cathode is 10 sccm–180 sccm. Figure 7 As shown, to ensure high peak power density and high NH3 yield, the optimal flow rate of NO gas at the cathode is 120 sccm. This optimizes gas mass transfer and reactant supply, avoiding incomplete reaction due to excessively low flow rates or reduced efficiency due to excessively high flow rates. It should be noted that optimizing the flow rates of H2 and NO (e.g., both H2 and NO flow rates are 120 sccm) ensures uniform gas distribution on the catalyst surface, improving reaction efficiency and product yield while maintaining stable plant operation.

[0027] In this embodiment, H migrates to the cathode through the proton exchange membrane. + NO entering through the NO inlet and e-entering through the external circuit - The reduction reaction occurs together in the cathode, and the NO reduction reaction pathway is controlled by the cathode catalyst to selectively generate N2, N2O or NH3.

[0028] The cathode catalyst comprises platinum group metals or their alloys, configured to regulate the NO reduction pathway within an applied potential range. This results in preferential generation of N2 or N2O in the 0.9 V–0.2 V potential range (NO primarily generates N2 or N2O via deoxygenation or coupling pathways); and generation of NH3 in the 0.2 V–0 V potential range (NO gains more electrons and protons, generating NH3 via hydrogenation). Therefore, through potential control (such as constant potential It scanning), electricity is preferentially generated at higher potentials (producing N2 or N2O), while NH3 is produced at lower potentials, achieving resource utilization and flexible energy output.

[0029] Specifically, the cathode catalyst is selected from one of Pt / C, Pd / C, Ru / C, PtPd / C, PtRu / C, PtCo / C, or PtCu / C. The loading of the cathode catalyst is 0.2 mg. M ·cm -2 -2 mg M ·cm -2(The subscript M indicates that the loading is metal). Therefore, the cost and performance can be balanced by optimizing the amount of cathode catalyst used, preventing insufficient reaction rate due to too low a loading or catalyst agglomeration and efficiency reduction due to too high a loading.

[0030] Different catalysts possess their own specific electrocatalytic properties, allowing users to select catalysts according to their needs and flexibly adjust product distribution and power generation efficiency. For example, combining... Figure 2 and Figure 3 As shown, the Pt / C catalyst has a peak power density of 178 mW·cm⁻¹ at 0.25 V. -2 The NO reduction pathway is N2 or N2O from 0.9 V to 0.2 V, and the NH3 pathway appears from 0.2 V to 0 V (the amount of NH3 produced at 0.1 V is 26.9 μg·h). -1 ·cm -2 At 0 V, it is 320.3 μg·h -1 ·cm -2 The Pd / C catalyst exhibits a peak power density of 81 mW·cm⁻¹ at 0.25 V. -2 The NO reduction pathway from 0.9 V to 0 V is either N2 or N2O; the PtPd / C catalyst has a peak power density of 207 mW·cm³ at 0.25 V. -2 The NO reduction pathway is N2 or N2O from 0.9 V to 0.1 V, and the NH3 pathway appears from 0.1 V to 0 V (the amount of NH3 produced at 0 V is 37.4 μg·h⁻¹). -1 ·cm -2 ).

[0031] In one embodiment, the cathode catalyst is PtPd / C with a loading of 1 mg. PtPd ·cm -2 The PtPd / C bimetallic catalyst enhances electrocatalytic activity through a synergistic effect, achieving a peak power density of 207 mW·cm⁻¹ at 0.25 V. -2 NH3 generation is achieved at low potentials (e.g., NH3 production is 37.4 μg·h⁻¹ at 0 V). -1 ·cm -2 Compared to single Pt / C or Pd / C, it improves the reaction rate and product flexibility.

[0032] Combination Figure 4 As shown in the optimization curve of 40% PtPd / C catalyst loading, the optimal loading of PtPd / C catalyst at 1 mg / L is optimal. PtPd ·cm -2It achieves optimal performance, ensuring a high electrochemical active area and stable reaction, maximizing power output and NH3 yield, while reducing the cost of using precious metals, improving the efficiency and selectivity of the NO reduction reaction, and avoiding the problems of insufficient activity or single product of single metal catalysts; it also achieves a high peak power density (207 mW·cm⁻¹). -2 ) and controllable NH3 yield.

[0033] A proton exchange membrane is positioned between the anode and cathode and configured to migrate protons generated at the anode to the cathode. This high-temperature proton exchange membrane operates in the range of 100℃-200℃, providing a high-temperature operating environment and solving the problems of catalyst poisoning and low proton conductivity at low temperatures.

[0034] In this embodiment, the proton exchange membrane is a polybenzimidazole (PBI) membrane, and the optimal operating temperature is 160°C. The PBI membrane exhibits high proton conductivity and thermal stability at 160°C, which enhances the catalyst's resistance to poisoning, extends the device's lifespan, and improves the NO reduction reaction rate and product selectivity.

[0035] An external circuit connects the anode and cathode and is configured to transfer electrons generated at the anode to the cathode to produce electrical energy. Protons migrate through a proton exchange membrane to the cathode, where they undergo a reduction reaction with NO and electrons, achieving simultaneous power generation and NO conversion.

[0036] The H2O evaporator is configured to supply water vapor to the cathode to regulate the reaction environment, with the H2O flow rate controlled between 0 ml / min and 0.22 ml / min. It should be noted that the H2O evaporator can regulate the cathode reaction environment, preventing catalyst deactivation or product deviation. Furthermore, combined with... Figure 5 The optimized flow rate curve of the H2O evaporator shows that the optimal flow rate of H2O is 0.08 ml / min.

[0037] Combination Figures 2-7 It is understood that, in a preferred embodiment, the HT-PEMFC device is configured as follows: the anode catalyst is 40% Pt / C (with a loading of 1 mg). Pt ·cm -2 The cathode catalyst is 40% PtPd / C (with a loading of 1 mg). PtPd ·cm -2 The H2 flow rate on the anode side was 120 sccm, the NO flow rate on the cathode side was 120 sccm, and the H2O evaporator flow rate was 0.08 ml / min; the reaction temperature of the PBI membrane was set to 160℃; and the reaction potential was controlled between 0.9 V and 0 V to achieve dynamic regulation of the NO reduction path.

[0038] The present invention also provides a method for generating electricity by reducing NO to produce ammonia, which is implemented by a high-temperature proton membrane fuel cell device for generating electricity by reducing NO to produce ammonia as described in any of the above embodiments, and includes the following steps: Supply H2 to the anode; NO gas is supplied to the cathode; At the operating temperature of the proton exchange membrane, a potential in the range of 0.9 V to 0 V is applied to regulate the NO reduction reaction pathway to selectively generate N2, N2O or NH3; Electrical energy is collected through external circuitry.

[0039] Furthermore, when the applied potential is in the range of 0.2 V to 0 V, NH3 will be generated.

[0040] In summary, the high-temperature proton exchange membrane fuel cell device and method for NO reduction to produce ammonia and generate electricity provided by the present invention have the following beneficial effects: (1) The proton exchange membrane operates under high temperature conditions (100℃-200℃), which improves the proton conductivity and catalyst activity, avoids the problem of catalyst poisoning at low temperature, enhances the catalyst's resistance to poisoning and reaction rate, and extends the life of the device. (2) The cathode catalyst, through its electrocatalytic properties, changes the reaction pathway of NO reduction under the potential regulation applied by the external circuit: at higher potentials (0.9 V-0.2 V), NO mainly generates N2 or N2O through deoxygenation or coupling pathways; at lower potentials (0.2 V-0 V), NO gains more electrons and protons and generates NH3 through hydrogenation pathway; thus, harmful NO pollutants are converted into high-value-added chemicals (such as NH3), realizing "turning waste into treasure", solving the resource waste problem of existing technologies that only detoxify NO into N2; it can adapt to different needs (such as priority power generation or ammonia production), enhancing the applicability and flexibility of the device; (3) Hydrogen is oxidized at the anode to generate protons and electrons. Electrons are transferred to the cathode through an external circuit to generate electrical energy. Protons migrate to the cathode through the proton exchange membrane and undergo a reduction reaction with NO and electrons to realize NO conversion and synchronous power generation. NO is processed while generating electricity, which improves the overall energy utilization efficiency, reduces external energy consumption, reduces secondary pollution, and reduces operating costs, resulting in significant environmental and economic benefits.

[0041] This invention is not limited to the embodiments described in the specification and implementation. Other modifications can be readily made by those skilled in the art, and therefore, without departing from the spirit and scope of the general concept as defined by the claims and their equivalents, this invention is not limited to the specific details, representative devices, and illustrated examples shown and described herein.

Claims

1. A high-temperature proton exchange membrane fuel cell device for NO reduction to produce ammonia and generate electricity, characterized in that, include: The anode is configured to receive H2 and undergo an oxidation reaction, producing protons and electrons. The cathode is configured to receive NO gas and carry out a reduction reaction, and the NO reduction reaction pathway is controlled by the cathode catalyst to selectively generate N2, N2O or NH3. A proton exchange membrane is disposed between the anode and the cathode and configured to migrate the protons generated by the anode to the cathode; the proton exchange membrane is a high-temperature proton exchange membrane with an operating temperature range of 100℃-200℃; Two gas diffusion layers are respectively disposed on the outside of the anode and the cathode; An external circuit is connected to the anode and the cathode and configured to transfer the electrons generated by the anode to the cathode to generate electrical energy; The cathode catalyst comprises a platinum group metal or an alloy thereof, configured to regulate the NO reduction pathway within an applied potential range, such that N2 or N2O is preferentially generated in the potential range of 0.9 V-0.2 V, and NH3 is generated in the potential range of 0.2 V-0 V.

2. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 1, characterized in that, The cathode catalyst is selected from one of Pt / C, Pd / C, Ru / C, PtPd / C, PtRu / C, PtCo / C, or PtCu / C, with a loading of 0.2 mg. M ·cm -2 -2 mg M ·cm -2 .

3. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 2, characterized in that, The cathode catalyst is PtPd / C with a loading of 1 mg. PtPd ·cm -2 .

4. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 1, characterized in that, The catalyst configured at the anode is Pt / C with a loading of 1 mg. Pt ·cm -2 .

5. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 1, characterized in that, Also includes: An H2O evaporator is configured to supply water vapor to the cathode to regulate the reaction environment of the cathode, with the H2O flow rate controlled at 0 ml / min-0.22 ml / min.

6. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 1, characterized in that, The flow rate of H2 received at the anode is 10 sccm-180 sccm, and the flow rate of NO gas received at the cathode is 10 sccm-180 sccm.

7. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 6, characterized in that, The flow rate of H2 received at the anode is 120 sccm, and the flow rate of NO gas received at the cathode is 120 sccm.

8. The high-temperature proton membrane fuel cell device for NO reduction to produce ammonia and generate electricity as described in claim 1, characterized in that, The proton exchange membrane is a polybenzimidazole membrane, and the operating temperature is 160°C.

9. A method for generating electricity by reducing NO to produce ammonia, implemented using a high-temperature proton membrane fuel cell device for generating electricity by reducing NO to produce ammonia as described in any one of claims 1-8, characterized in that, Includes the following steps: Supply H2 to the anode; NO gas is supplied to the cathode; At the operating temperature of the proton exchange membrane, a potential in the range of 0.9 V to 0 V is applied to regulate the NO reduction reaction pathway to selectively generate N2, N2O or NH3. Electrical energy is collected through external circuitry.

10. The method for generating electricity by reducing NO to produce ammonia as described in claim 9, characterized in that, When the applied potential is in the range of 0.2 V to 0 V, NH3 will be generated.

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