Integrated electrocatalysis system using MOF-graphene hybrid electrodes for the conversion of carbon dioxide

Abstract

A system for the electrochemical conversion of carbon dioxide, the system comprising the following: a reactor housing that defines a closed electrochemical chamber; a working electrode arrangement arranged in the electrochemical chamber, comprising a conductive support and an electrocatalytic layer designed as a hybrid structure, containing a metal-organic framework material integrated with a graphene-based conductive material, wherein the metal centers of the metal-organic framework are configured as catalytically active centers for carbon dioxide reduction; a counter electrode arrangement which is arranged in the electrochemical chamber in a spatial position opposite to the working electrode arrangement; an ion-conducting separator that is positioned between the working electrode arrangement and the counter electrode arrangement and is configured to allow ion transport while preventing direct electrical contact between the electrode arrangements; an electrolyte storage unit configured to hold an electrolyte in ionic connection with the working electrode assembly and the counter electrode assembly; a gas supply unit that is fluidically connected to the reactor housing and configured to introduce carbon dioxide into the working electrode assembly under controlled flow conditions; a current sensing unit that is electrically connected to the working electrode assembly and the counter electrode assembly; and a power control unit that is electrically coupled to the current collection unit and is configured to apply a controlled electrical potential or current to the working electrode assembly and the counter electrode assembly to promote the electrochemical reduction of carbon dioxide.

Description

Technical field of the invention:

[0001] The present disclosure relates generally to the field of electrochemical energy conversion and carbon capture and utilization. In particular, it relates to an integrated electrocatalysis system with metal-organic frameworks and graphene hybrid electrodes for the electrochemical conversion of carbon dioxide into valuable chemical products. The invention further relates to an integrated electrochemical device structure designed for efficient carbon dioxide reduction under controlled electrochemical, thermal, and mass transfer conditions. Background of the invention:

[0002] The steadily increasing concentration of atmospheric carbon dioxide resulting from industrial activities, the combustion of fossil fuels, and chemical production processes has become a pressing environmental problem due to its direct contribution to climate change and global warming. While conventional carbon capture and storage (CCS) strategies are effective in reducing emissions, they are subject to high operating costs, higher energy consumption, and long-term storage risks. Therefore, research efforts are increasingly focused on CCS conversion technologies that transform carbon dioxide into fuels, chemicals, and industrial feedstocks.

[0003] Electrochemical carbon dioxide conversion has proven to be a promising approach, as it enables the direct use of electrical energy, including renewable energy sources, to reduce carbon dioxide at or near-ambient levels. However, existing electrochemical systems often exhibit low catalytic selectivity, high overvoltages, low current density, and limited electrode stability. Traditional metal electrodes such as copper, silver, and tin have a limited active surface area and are subject to surface degradation during prolonged operation. Furthermore, mass transport limitations and inefficient electron transfer pathways further reduce system efficiency.

[0004] Metal-organic frameworks (MOFs) have gained importance as catalyst materials due to their high porosity, tunable coordination environments, and ability to incorporate catalytically active metal centers. However, most MOFs exhibit low intrinsic electrical conductivity, which limits their direct application as electrocatalysts. Graphene-based materials, on the other hand, offer exceptional electrical conductivity, mechanical stability, and a large surface area, but exhibit insufficient catalytic specificity for carbon dioxide reduction. The integration of MOFs with graphene materials offers the opportunity to combine a high density of catalytic centers with efficient electron transport.Despite this potential, there remains a need for a system-wide electrocatalysis architecture that effectively integrates MOF-graphene hybrid electrodes into a functional electrochemical device that enables sustainable and efficient carbon dioxide conversion.

[0005] The rapid increase in atmospheric carbon dioxide concentrations due to the combustion of fossil fuels, cement production, and large-scale industrial activities has intensified the demand for effective carbon management technologies. Conventional mitigation strategies have thus far focused primarily on carbon capture and storage (CCS), in which carbon dioxide is separated from flue gases and stored in geological formations. While these approaches can reduce emissions at point sources, they are associated with high capital costs, significant energy costs, long-term monitoring requirements, and unresolved risks related to leaks and a lack of public acceptance. Therefore, carbon capture and utilization (CCU) has gained importance as an alternative paradigm.The goal is not only to remove carbon dioxide from emission streams, but also to convert it into valuable chemicals, fuels and materials, thereby creating economic incentives for emission reduction.

[0006] Among the various methods for carbon utilization, electrochemical carbon dioxide conversion has attracted considerable attention due to its compatibility with renewable energy sources and its ability to operate under relatively mild temperature and pressure conditions. Electrochemical reduction enables the direct conversion of carbon dioxide into products such as carbon monoxide, formic acid, methane, ethylene, and alcohols through controlled electron transfer processes. However, despite decades of research, the widespread use of electrochemical carbon dioxide reduction systems remains limited by fundamental and practical challenges related to catalyst performance, system efficiency, selectivity, and stability.

[0007] Early electrochemical systems were predominantly based on massive metal electrodes, including copper, silver, gold, tin, and lead, each exhibiting different catalytic behavior in carbon dioxide reduction. While copper-based electrodes can generate multi-chain hydrocarbons and oxygen-containing compounds, they require high overpotentials and exhibit low product selectivity due to complex reaction pathways and competing hydrogen evolution reactions. Silver and gold electrodes show relatively high selectivity for carbon monoxide formation but are expensive and have limited long-term stability under industrial operating conditions. Tin and lead favor formate formation but often exhibit rapid surface passivation and decreasing activity.All these systems share the characteristic of a limited density of catalytically active centers and insufficient control over reaction intermediates at the electrode surface.

[0008] To overcome these limitations, nanostructured catalysts and supported metal nanoparticles have been investigated to increase surface area and enhance catalytic activity. While nanostructuring improves initial performance, such materials often undergo agglomeration, surface reconstruction, or detachment from the support during extended electrochemical cycles, leading to performance degradation. Furthermore, the lack of well-defined active sites in many nanoparticle-based catalysts restricts pathway control and the selective stabilization of desired intermediates. Consequently, product distribution remains broad and difficult to control, complicating subsequent separation and reducing overall process efficiency.

[0009] Carbon-based catalyst supports, including carbon black, carbon nanotubes, and graphene-based materials, have been introduced to improve electrical conductivity and catalyst dispersion. Graphene, in particular, offers exceptional electron mobility, a large surface area, and mechanical stability. Graphene-supported metal catalysts exhibit improved charge transfer properties and higher stability compared to unsupported metal electrodes. However, graphene itself lacks intrinsic catalytic specificity for carbon dioxide reduction, and the catalytic performance of graphene-supported systems remains largely determined by the properties of the deposited metal species. Furthermore, the weak interaction between graphene supports and certain metal catalysts can lead to catalyst detachment or morphological changes under electrochemical stress.

[0010] Metal-organic frameworks (MOFs) have established themselves as a distinct class of porous materials with highly tunable structures, offering unprecedented control over pore size, surface chemistry, and metal coordination environments. The modular structure of MOFs allows for the precise design of catalytic centers at the molecular level, enabling the selective adsorption and activation of carbon dioxide molecules. Various MOFs containing transition metals such as copper, iron, cobalt, nickel, and zinc have demonstrated promising catalytic activity in carbon dioxide conversion, both thermally and electrochemically. The large internal surface area and ordered porosity of MOFs allow for high reagent loading and efficient mass transport at the nanoscale.

[0011] Despite these advantages, the practical application of metal-organic frameworks (MOFs) in electrochemical systems is severely limited due to their low electrical conductivity. Most MOFs behave like electrical insulators or weak semiconductors, which restricts electron transfer to the active metal centers during electrochemical reactions. Therefore, MOF-based electrodes often require high overvoltages and exhibit low current densities when used alone. While attempts to improve conductivity through ligand modification, metal substitution, or partial carbonization have yielded incremental improvements, they frequently compromise structural integrity or catalytic specificity.

[0012] To overcome these shortcomings, hybrid approaches combining metal-organic frameworks (MOFs) with conductive materials have been proposed. In particular, the integration of MOFs with graphene-based materials has proven promising in laboratory studies. Graphene provides continuous conductive pathways, while MOFs offer a high density of well-defined catalytic centers. However, many existing hybrid systems are limited to powdered catalysts applied to inert substrates using binders. This results in additional interfacial resistance and reduces the effective active surface area. Furthermore, binder-based electrodes often exhibit mechanical instability, pore clogging, and uneven catalyst distribution, leading to inconsistent reaction zones and reduced long-term performance.

[0013] Conventional electrochemical reactors for carbon dioxide reduction are often based on simple, planar electrode configurations in liquid electrolytes at the system level. These architectures exhibit significant mass transport limitations, particularly for gaseous carbon dioxide, which is poorly soluble in aqueous electrolytes. This makes the carbon dioxide feed rate to the catalyst surface a limiting factor, leading to low current densities and increased competition from hydrogen evolution. Gas diffusion electrodes were introduced to address this problem by directly contacting gaseous carbon dioxide with the catalyst layer. However, integrating advanced catalyst materials into stable gas diffusion electrode structures remains a challenge.

[0014] Furthermore, many existing electrochemical systems lack integrated control of temperature, pressure, electrolyte composition, and product separation. This leads to fluctuating operating conditions, which accelerate catalyst degradation and reduce selectivity. The lack of scalable, modular reactor designs further limits the transferability of catalyst performance achieved on a laboratory scale to industrially relevant systems. Despite significant advances in catalyst development, the overall efficiency and reliability of existing electrochemical carbon dioxide conversion systems therefore remain insufficient for large-scale industrial applications.

[0015] Another crucial disadvantage of current solutions is the limited durability of the electrodes during continuous operation. Repeated redox cycles, local pH fluctuations, and the accumulation of reaction intermediates can lead to structural collapse of porous materials, metal dissolution, and surface poisoning. These effects are particularly pronounced in hybrid systems, where differing mechanical or thermal properties of the components lead to delamination or cracking over time. The lack of robust electrode architectures that ensure close contact between conductive and catalytic components under operational stress presents a major obstacle to commercialization.

[0016] Given these challenges, there is a clear need for an electrocatalysis system that combines a high density of catalytic centers, efficient electron transport, controlled mass transport, and structural stability in an integrated device architecture. Previous solutions have addressed individual aspects of the problem but have not been able to provide a holistic system that enables sustainable, efficient, and selective carbon dioxide conversion. The development of an electrocatalysis system with metal-organic frameworks and graphene hybrid electrodes in a purpose-built electrochemical device structure represents a crucial advancement in overcoming the limitations of the state of the art and enabling practical technologies for carbon dioxide utilization. Summary of the invention:

[0017] The present disclosure describes an electrocatalysis system with MOF-graphene hybrid electrodes for the electrochemical conversion of carbon dioxide into reduced carbon products such as carbon monoxide, formate, hydrocarbons, or alcohols. The system integrates structurally optimized hybrid electrodes with controlled gas supply, electrolyte management, and electrical control to achieve high conversion efficiency, improved selectivity, and long-term operational stability. The invention further comprises a device structure with an electrochemical reactor housing, electrode arrays, a current collection architecture, and flow management components that optimize electron transfer, ion transport, and reactant accessibility.

[0018] The present invention aims to provide an electrocatalysis system that efficiently converts carbon dioxide into valuable chemical products. This is achieved through the use of hybrid electrodes that integrate metal-organic frameworks with graphene-based conductive materials. This results in increased catalytic activity and improved electron transfer properties compared to conventional electrode systems. The invention aims to overcome the intrinsic conductivity limitations of metal-organic frameworks while maintaining their high density of catalytic centers and tunable coordination environments.

[0019] A further objective of the invention is to provide an electrochemical system architecture that enables high current density operation at reduced overvoltages by forming continuous and low-resistance electrical paths between an external current source and catalytically active metal centers within the hybrid electrode structure. By ensuring efficient charge transport and minimizing interfacial resistance, the invention aims to improve the overall energy efficiency of carbon dioxide electroreduction processes.

[0020] A further objective of the invention is to increase the selectivity towards the desired carbon dioxide reduction products by stabilizing specific reaction intermediates within the porous structure of the metal-organic framework component while simultaneously suppressing competing side reactions such as hydrogen evolution. The invention aims to provide controlled catalytic microenvironments that enable predictable and adjustable product distribution.

[0021] A further objective of the invention is to overcome mass transport limitations in carbon dioxide supply to electrochemical systems by providing electrode and device configurations that enable effective gas, liquid, and ion transport to and from the catalytic centers. The invention aims to improve reactant accessibility and product separation through optimized electrode porosity and integrated flow management within the electrochemical cell.

[0022] A further objective of the invention is to provide a mechanically robust and chemically stable electrode structure that maintains its catalytic performance even under prolonged electrochemical operation. The invention aims to prevent degradation phenomena such as catalyst detachment, pore collapse, and structural delamination through strong interfacial integration between the metal-organic framework and the graphene components.

[0023] A further objective of the invention is to provide a modular and scalable electrochemical device structure that can be easily adapted to applications for carbon dioxide conversion on a laboratory, pilot, or industrial scale. The invention aims to enable simple scaling of the conversion capacity by connecting multiple reactor units while ensuring consistent performance under all operating conditions.

[0024] A further objective of the invention is the integration of the electrocatalysis system with renewable energy sources by enabling operation under dynamically varying electrical input voltages without impairing catalytic stability or selectivity. The invention aims to promote sustainable carbon utilization by aligning electrochemical conversion processes with the intermittent generation of renewable energies.

[0025] Another objective of the invention is to provide an electrocatalysis system with improved monitoring and control capabilities, enabling the regulation of electrochemical parameters such as potential, current density, temperature and reagent flow to ensure optimal conversion efficiency and system longevity.

[0026] Another objective of the invention is to offer a practical and industrially applicable solution for carbon dioxide utilization that reduces greenhouse gas emissions while simultaneously producing economically valuable products, thereby contributing to environmental sustainability and initiatives for a circular economy with carbon. BRIEF DESCRIPTION OF THE IMAGE

[0027] These and other features, aspects and advantages of the present invention will be better understood if the following detailed description is read with reference to the accompanying drawing, in which the same symbols represent the same parts: Fig. Figure 1 shows a block diagram of a system for the electrochemical conversion of carbon dioxide.

[0028] Furthermore, those skilled in the art will recognize that the elements in the drawing are presented for the sake of simplicity and may not be drawn to scale. With regard to the construction of the device, one or more components may be represented in the drawing by conventional symbols. The drawing may show only those specific details relevant to understanding the embodiments of the present disclosure, in order to avoid cluttering the drawing with details that are already apparent to those skilled in the art from the description contained herein. Detailed description of the invention

[0029] To facilitate understanding of the principles of the invention, reference is made below to the embodiment shown in the drawing, which is described using specific terms. It is understood, however, that this does not limit the scope of protection of the invention. Rather, modifications and further developments of the depicted system, as well as further applications of the inventive principles shown therein, are conceivable, insofar as they would normally occur to a person skilled in the art in the field of the invention.

[0030] It will be clear to those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not to be understood as a limitation thereof.

[0031] References to “an aspect”, “another aspect”, or similar phrases in this description mean that a particular feature, structure, or property described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, phrases such as “in one embodiment”, “in another embodiment”, and similar expressions in this description may, but do not necessarily, all refer to the same embodiment.

[0032] Likewise, the specification of one or more devices, subsystems, elements, structures or components with the addition "includes...a" without further restrictions does not exclude the existence of other devices, other subsystems, other elements, other structures, other components, additional devices, additional subsystems, additional elements, additional structures or additional components.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as generally known to those skilled in the art in the field to which this invention belongs. The system and the examples contained herein serve only for illustration and are not to be construed as a limitation.

[0034] Embodiments of the present disclosure are described in detail below with reference to the attached drawing.

[0035] In Fig.Figure 1 shows a block diagram of a system for the electrochemical conversion of carbon dioxide. The system 100 comprises: a reactor housing (102) with a closed electrochemical chamber; a working electrode assembly (104) within the electrochemical chamber, consisting of a conductive support and an electrocatalytic layer in a hybrid structure of a metal-organic framework material (104a) and a graphene-based conductive material (104b), wherein the metal centers of the metal-organic framework act as catalytically active centers for carbon dioxide reduction; a counter electrode assembly (106) in the electrochemical chamber opposite the working electrode assembly; an ion-conducting separator (108) between the working and counter electrode assemblies, which allows ion transport but prevents direct electrical contact between the electrode assemblies;an electrolyte container unit (110) for receiving the electrolyte in ionic connection with the working and counter electrode assembly; a gas supply unit (112) fluidically connected to the reactor housing and configured to introduce carbon dioxide into the working electrode assembly under controlled flow conditions; a current collection unit (114) electrically connected to the working and counter electrode assembly; and a power control unit (116) electrically connected to the current collection unit and configured to apply a controlled electrical potential or current to the working and counter electrode assembly to drive the electrochemical reduction of carbon dioxide.

[0036] In one embodiment, the metal-organic framework material comprises a crystalline coordination network formed from metal ions or metal clusters coordinated with organic linker molecules, wherein the metal ions or metal clusters are selected to ensure a specific binding affinity for carbon dioxide molecules within the pores of the metal-organic framework.

[0037] In one embodiment, the graphene-based conductive material (104b) comprises graphene layers, reduced graphene oxide layers or doped graphene layers arranged to form a continuous electrically conductive network extending through the electrocatalytic layer.

[0038] In one embodiment, the electrocatalytic layer is formed by in-situ growth of the metal-organic framework material on surfaces of the graphene-based conductive material, thereby establishing direct interfacial contact between catalytic centers and conductive paths.

[0039] In one embodiment, the conductive support structure of the working electrode arrangement (104) comprises a porous, electrically conductive substrate configured to mechanically support the electrocatalytic layer while simultaneously allowing the transport of electrolyte ions and gaseous carbon dioxide.

[0040] In one embodiment, the gas supply unit (112) comprises a gas diffusion structure located in close proximity to the working electrode arrangement and configured to distribute carbon dioxide uniformly over an active surface of the electrocatalytic layer.

[0041] In one embodiment, the working electrode arrangement (104) is configured as a gas diffusion electrode such that a first side of the electrocatalytic layer is exposed to gaseous carbon dioxide and an opposite side of the electrocatalytic layer is in contact with the electrolyte.

[0042] In one embodiment, the ion-conducting separator (108) comprises a polymer membrane configured to selectively conduct cations or anions generated during electrochemical operation while simultaneously restricting the passage of reaction products between the electrode chambers.

[0043] In one embodiment, the electrolyte storage unit (110) is configured to retain an aqueous electrolyte with controlled ionic strength and controlled pH to stabilize electrochemical reduction reactions occurring at the metal centers of the metal-organic framework.

[0044] In one embodiment, the electrolyte container unit (110) is configured to accommodate a non-aqueous or mixed solvent electrolyte selected to suppress hydrogen evolution and increase selectivity towards carbon dioxide reduction products.

[0045] The electrochemical carbon dioxide conversion system is implemented as a physical electrochemical reactor. The reactor housing is designed as a sealed, pressure-resistant chamber made of corrosion-resistant metal or polymer to define the enclosed electrochemical chamber. The working electrode assembly comprises a porous, conductive substrate, such as a metal mesh, carbon mesh, or graphite plate, which mechanically supports an electrocatalytic layer. This layer is a composite coating consisting of a metal-organic framework grown directly on a graphene or reduced graphene oxide network and ensures both catalytic activity and electrical conductivity. The counter electrode assembly is designed as a conductive plate or fabric opposite the working electrode, completing the electrochemical cell.The ion-conducting separator is implemented as a polymer electrolyte membrane or ceramic membrane, physically located between the electrodes to enable ion transfer while preventing short circuits. The electrolyte container unit comprises an internal reservoir or flow channel system within the reactor housing that holds and circulates aqueous or non-aqueous electrolyte with controlled pH and ionic strength.The gas supply unit is designed as a pressurized gas inlet manifold with a gas diffusion layer or porous gas distribution plate located next to the working electrode to introduce carbon dioxide and distribute it evenly over the catalytic surface; the current sensing unit consists of metallic busbars, conductive leads, and terminals that electrically connect each electrode assembly to an external circuit; and the power control unit includes a programmable DC power supply or a potentiostat electrically connected to the current sensing unit to apply and regulate the electrochemical potential or current necessary for carbon dioxide reduction.

[0046] During initialization, the reactor housing is conditioned by introducing a selected electrolyte into the electrochemical chamber via the electrolyte container unit until the working and counter electrode assemblies are fully wetted at their respective electrolyte contact surfaces. The ion-conducting separator establishes ionic continuity between the electrode assemblies while simultaneously providing electrical isolation. In parallel, the gas supply unit initiates a controlled flow of carbon dioxide into the electrochemical chamber and directs the gas to the working electrode assembly via the gas diffusion structure. The system technology ensures that the carbon dioxide partial pressure and flow rate are maintained within predefined thresholds to prevent gas shortages or excessive pressure buildup at the electrocatalytic layer.

[0047] After stabilizing the electrochemical environment, the power control unit applies an initial electrical potential between the working and counter electrodes via the current collector unit. The magnitude of the applied potential is selected based on stored operating parameters corresponding to the composition of the metal-organic framework and the graphene network configuration of the electrocatalytic layer. This initial bias is applied gradually to avoid abrupt current spikes that could lead to local heating or structural stresses in the hybrid electrode. The system monitors the current response in real time and compares the measured current density with the target values ​​derived from calibration data.

[0048] When an electrical bias is applied, electrons are transported from the power control unit, via the current collector unit, into the conductive substrate of the working electrode assembly. The graphene-based conductive material within the electrocatalytic layer forms a continuous electron transport network, enabling rapid distribution of electrons to the metal centers of the metal-organic framework. Carbon dioxide molecules, supplied by the gas supply unit, diffuse through the pores of the gas diffusion structure and enter the porous network of the metal-organic framework, where they are adsorbed onto catalytically active metal centers. The system implicitly controls this step by maintaining stable electrical and mass transport conditions that favor adsorption over desorption.

[0049] Following adsorption, carbon dioxide molecules are electrochemically reduced stepwise at the metal centers of the metal-organic framework. The system maintains the applied potential within a controlled operating window, promoting the formation of desired reaction intermediates while suppressing competing hydrogen evolution reactions. Stabilization of the intermediates is achieved through coordination interactions within the pores of the metal-organic framework, which is ensured by avoiding excessive overpotentials. The graphene network ensures that electron supply to each catalytic center is not rate-determining, thus supporting uniform reaction kinetics across the entire electrode surface.

[0050] Throughout the entire reduction process, the sensor unit continuously records operating data such as electrode potential, current density, temperature in the electrochemical chamber, and carbon dioxide flow rate. These measurements are transmitted to the power control unit, which dynamically adjusts the applied potential or current using a feedback system. If the current density deviates from a predefined target range, the power control unit incrementally modifies the electrical input power to restore steady-state operation. If temperature fluctuations are detected, the thermal control unit is activated to dissipate excess heat or supply additional heat to ensure reaction stability.

[0051] The system also takes mass transfer into account by correlating the measured current density with the carbon dioxide flow rate. If the current demand increases, indicating higher reactant consumption, the gas supply is adjusted proportionally to the amount of carbon dioxide. Conversely, if the current density decreases due to temporary saturation or product accumulation, the system reduces the gas flow to ensure efficient use of the supplied carbon dioxide. The reaction products generated at the working electrode assembly are removed from the electrocatalytic layer by controlled electrolyte circulation and product discharge pathways within the reactor housing.

[0052] On the counter electrode side, complementary electrochemical reactions take place to balance the charge transfer through the ion-conducting separator. The separator allows the ions generated at the working electrode to migrate to the counter electrode, thus maintaining electrical neutrality in the electrochemical chamber. The system ensures sufficient ionic conductivity by monitoring the electrolyte state and adjusting the electrolyte supply in case of deviations in conductivity or pH.

[0053] During continuous operation, the system utilizes periodic stabilization cycles in which the applied potential is briefly adjusted within a narrow range to minimize surface contamination and prevent the accumulation of strongly bound intermediate products at the metal-organic framework sites. These stabilization cycles maintain catalytic activity without compromising the hybrid electrode structure. During these cycles, the graphene component provides mechanical reinforcement, thus preventing delamination or pore collapse under repeated electrochemical stress.

[0054] For continuous or long-term operation, the system utilizes a maintenance function that evaluates long-term trends in power output, selectivity indicators (derived from product detection), and the electrical resistance of the working electrode assembly. Upon detecting a gradual degradation of performance, the power control unit adjusts the operating parameters to compensate while maintaining the target conversion power. If predefined degradation thresholds are exceeded, the system initiates a controlled shutdown sequence in which the electrical bias is gradually reduced, the gas flow is decreased, and the electrolyte circulation is stabilized to prevent damage to the electrocatalytic layer.

[0055] The described technology, control system, and operating logic enable the claimed system to perform an efficient, selective, and continuous electrochemical conversion of carbon dioxide. By coordinating electrical input, mass transfer, thermal management, and real-time feedback, the system maintains optimal reaction conditions at the metal-organic framework graphene hybrid electrodes, thus fulfilling the functional objectives defined in the system claims.

[0056] According to the present disclosure, an electrocatalysis system is provided, the working electrode of which comprises a hybrid electrocatalytic layer. This layer consists of a metal-organic framework material (MOF) and a graphene-based conductive matrix. The MOF contains a crystalline coordination network of metal ions or metal clusters linked by organic ligands. The metal centers are catalytically active for carbon dioxide reduction. The graphene component can comprise graphene sheets, graphene isotopes, or graphene oxide, reduced graphene oxide, or doped graphene, configured to ensure continuous electron conduction pathways throughout the hybrid structure.

[0057] The MOF-graphene hybrid electrode is fabricated by either growing the metal-organic framework in situ on the graphene surface or depositing it as a conformal, porous layer onto graphene sheets. This configuration enables close interfacial contact between the catalytically active MOF centers and the electrically conductive graphene network. This minimizes charge transfer resistance and facilitates rapid electron injection into the catalytic centers during electrochemical operation. The porous structure of the metal-organic framework provides a large surface area and accessible diffusion channels for carbon dioxide molecules, while the graphene matrix ensures mechanical stability and electrical conductivity.

[0058] The electrocatalysis system comprises an electrochemical cell with a MOF graphene hybrid working electrode, a counter electrode, and an ion-conducting separator or membrane between the electrodes. The separator facilitates ion transport and electrically insulates the electrodes to prevent short circuits. An electrolyte, which can be aqueous, non-aqueous, or solid, is introduced into the cell and is selected to ensure efficient ion conductivity and stability under applied electrochemical potentials.

[0059] The graphene hybrid electrode can include an adjacent gas diffusion layer. This gas diffusion layer enables a uniform distribution of carbon dioxide across the electrode surface and improves the contact between gas, liquid, and solid. In certain embodiments, the MOF graphene hybrid electrode itself is configured as a gas diffusion electrode, with the porous hybrid layer in direct contact with gaseous carbon dioxide on one side and with electrolyte on the opposite side, thereby reducing mass transport limitations.

[0060] An external power supply is electrically connected to the working and counter electrodes via current collectors, thus enabling the application of a controlled potential or current to the electrodes. When an electrical voltage is applied, electrons are transferred from the external circuit across the graphene network to the metal centers of the metal-organic framework (MOF). There, carbon dioxide molecules adsorbed in the MOF pores are electrochemically reduced. Reaction intermediates are stabilized by the coordination environment of the MOF, leading to increased selectivity for the desired reduction products. The reduced carbon products are then desorbed and transported from the electrode surface for collection.

[0061] The system can also include temperature control components integrated into the electrochemical cell housing to maintain the operating temperature within a predefined range, thereby stabilizing the reaction kinetics and preventing degradation of the MOF-graphene hybrid structure. Additionally, sensors can be integrated to monitor parameters such as electrode potential, current density, gas flow rate, electrolyte composition, and product concentration, enabling closed-loop control of the electrocatalysis process.

[0062] The electrocatalysis system and associated device presented here are suitable for carbon dioxide utilization in chemical production, the synthesis of renewable fuels, and carbon recycling. The integration of MOF-graphene hybrid electrodes enables improved efficiency, selectivity, and durability compared to conventional electrocatalytic systems, thus supporting the sustainable industrial application of electrochemical carbon dioxide conversion technologies.

[0063] The drawing and the preceding description illustrate embodiments. Those skilled in the art will recognize that one or more of the described elements can be combined to form a single functional element. Alternatively, certain elements can be divided into several functional elements. Elements of one embodiment can be added to another. For example, the process flows described here can be modified and are not limited to the manner described herein. Furthermore, the actions of a flowchart need not be performed in the sequence shown; nor do all actions necessarily need to be carried out. Actions that do not depend on other actions can be performed in parallel with the other actions. The scope of protection of the embodiments is in no way limited by these specific examples. Numerous variations, whether explicitly stated in the description or not, such as...Differences in structure, dimensions, and materials are possible. The scope of protection of the embodiments is at least as comprehensive as described by the following claims.

[0064] The advantages, other benefits, and problem solutions have been described above with reference to specific embodiments. However, the advantages, benefits, problem solutions, and any components that can effect or enhance an advantage, benefit, or solution are not to be construed as critical, necessary, or essential features or components of the claims. REFERENCES 100 A System for the Electrochemical Conversion of Carbon Dioxide. 102 reactor casings 104 Working electrode arrangement 104a Metal-organic framework material 104b Graphene-Based Conductive Material 106 Counter electrode arrangement 108 Ion-conducting separator 110 Electrolyte storage unit 112 Gas supply unit 114 Electricity collection point 116 Power control unit

Claims

[1] A system for the electrochemical conversion of carbon dioxide, the system comprising: a reactor housing that defines a closed electrochemical chamber; a working electrode arrangement located in the electrochemical chamber, comprising a conductive support and an electrocatalytic layer designed as a hybrid structure, containing a metal-organic framework material integrated with a graphene-based conductive material, wherein the metal centers of the metal-organic framework are configured as catalytically active centers for carbon dioxide reduction; a counter-electrode arrangement which is arranged in the electrochemical chamber in a spatial position opposite to the working electrode arrangement; an ion-conducting separator that is positioned between the working electrode arrangement and the counter electrode arrangement and is configured to allow ion transport while preventing direct electrical contact between the electrode arrangements; an electrolyte storage unit configured to hold an electrolyte in ionic connection with the working electrode assembly and the counter electrode assembly; a gas supply unit that is fluidically connected to the reactor housing and configured to introduce carbon dioxide into the working electrode assembly under controlled flow conditions; a current sensing unit that is electrically connected to the working electrode assembly and the counter electrode assembly; and a power control unit that is electrically coupled to the current collection unit and is configured to apply a controlled electrical potential or current to the working electrode assembly and the counter electrode assembly to promote the electrochemical reduction of carbon dioxide. [2] System according to claim 1, wherein the metal-organic framework material comprises a crystalline coordination network formed from metal ions or metal clusters coordinated with organic linker molecules, and wherein the metal ions or metal clusters are selected to ensure a specific binding affinity for carbon dioxide molecules within the pores of the metal-organic framework. [3] System according to claim 1, wherein the graphene-based conductive material comprises graphene layers, reduced graphene oxide layers or doped graphene layers arranged to form a continuous electrically conductive network extending through the electrocatalytic layer. [4] System according to claim 1, wherein the electrocatalytic layer is formed by in-situ growth of the metal-organic framework material on surfaces of the graphene-based conductive material, thereby establishing direct interfacial contact between catalytic centers and conductive pathways. [5] System according to claim 1, wherein the conductive support structure of the working electrode arrangement comprises a porous, electrically conductive substrate configured to mechanically support the electrocatalytic layer while simultaneously allowing the transport of electrolyte ions and gaseous carbon dioxide. [6] System according to claim 1, wherein the gas supply unit comprises a gas diffusion structure located in the immediate vicinity of the working electrode arrangement and configured to distribute carbon dioxide uniformly over an active surface of the electrocatalytic layer. [7] System according to claim 1, wherein the working electrode arrangement is configured as a gas diffusion electrode such that a first side of the electrocatalytic layer is exposed to gaseous carbon dioxide and an opposite side of the electrocatalytic layer is in contact with the electrolyte. [8] System according to claim 1, wherein the ion-conducting separator comprises a polymer membrane configured to selectively conduct cations or anions generated during electrochemical operation while simultaneously restricting the passage of reaction products between the electrode chambers. [9] System according to claim 1, wherein the electrolyte storage unit is configured to retain an aqueous electrolyte with controlled ionic strength and controlled pH to stabilize electrochemical reduction reactions occurring at the metal centers of the metal-organic framework. [10] System according to claim 1, wherein the electrolyte storage unit is configured to retain a non-aqueous or mixed solvent electrolyte selected to suppress hydrogen evolution and increase selectivity towards carbon dioxide reduction products.

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