EP4731817A2 - Electrochemical device and respective uses - Google Patents

Abstract

The present disclosure relates to an electrochemical device with enhanced mass transfer and respective uses. It is disclosed an electrochemical device comprising at least one reaction fluid distributor with a network for flowing one or more reaction fluids, wherein said reaction fluid distributor network comprises an array of chambers, each chamber being interconnected by at least two channels to at least two other chambers; and at least two electrodes, an anode and a cathode, to which electrical energy is provided to produce one or more chemical reactions.

Description

D E S C R I P T I O N

ELECTROCHEMICAL DEVICE AND RESPECTIVE USES

TECH NICAL FIELD

[0001] The present disclosure relates to an electrochemical device with enhanced mass transfer and respective uses.

BACKGROUND

[0002] Electrochemical devices that generate electrochemical reactions are process units to which a sufficient electrical potential is applied between electrodes to drive the desired electrochemical reactions. Said electrochemical reactions are characterized by the reaction kinetics, which dictate their productivity, and primarily happen at the surface of the electrodes. The productivity of most electrochemical reactions with commercial value is limited by the mass transfer rate of reactants and products to and from these electrodes, and often reactants and products must also be transferred across separators. Because of that, there is a need to go beyond conventional electrochemical devices that do not promote convective mass transfer and develop new designs that enhance the rate of reactants supplied to and removed from the electrode surfaces and transferred across separators.

[0003] Electrodes include anodes and cathodes. In electrochemical devices that generate electrochemical reactions, the electrochemical potential applied between two electrodes typically drives oxidation reactions at the anode and reduction reactions at the cathode. The electrochemical driving force obviates the use of high temperature and pressure, which allows higher energy efficiency and enables the use of simpler reactors that can range from small to large scale. Furthermore, in electrochemical devices, the potential between the two electrodes can be used as a tuning variable to adjust the reaction selectivity and activity towards the products of interest.

[0004] Several configurations for electrochemical devices have been proposed. For example, document US20040229117A1 shows the stacking of an electrochemical device with an anode and a cathode layer, impregnated with an electrolyte, placed facing each other, and with a separator between them. A current collector is placed in contact with each electrode layer and a gasket is used on both sides to seal the pair of stacked electrodes.

[0005] Document US2019/0010620A1 discloses a 3-compartment system formed and separated by membranes that form an anode compartment, a cathode compartment, and a compartment for fluid flow located between the anode and the cathode. This system is addressed to the electroreduction of carbon dioxide to formic acid. An anion exchange membrane (AEM) was placed between a gas diffusion electrode at the cathode side and the central flow compartment. In this configuration, the liquid electrolyte was supplied in the central compartment and the carbon dioxide gas was supplied in the outside compartment. Placing an AEM between the liquid compartment and the gas diffusion electrode kept the gas diffusion electrode from flooding, which may impair the productivity of the electrochemical device.

[0006] Document US9481939B2 discloses a strategy to increase the Faradaic efficiency by introducing an auxiliary membrane that separates the anode and cathode chambers. In this way, only certain reactants or intermediate reaction species can move from one electrode to another.

[0007] Additional cell designs have been used before for catalytic electrochemical reactions. Earlier works primarily used liquid electrolytes confined between a cathode and an anode. More recent scientific works and technology developments tweaked this original configuration to incorporate dry, partly or totally, solid electrolytes. A recent example of this new configuration is in the document US7704369. In this case, the cathodic catalyst is supported and sandwiched in a catalyst layer in contact with both liquid and gas, which allows creating solid-gas-liquid interfaces, where high reactivity is achieved while simultaneously enabling rapid replenishing of the reactant, which moves from the gas to the liquid phase.

[0008] Reaction efficiency can be improved by applying photoactive materials in the electrodes, giving rise to photoelectrodes and photoelectrochemical processes. The use of photoelectrodes, which can be photoanodes or photocathodes, increases the amount of reactive species and diminishes the applied electrochemical potential. Document US8663447B2 is a good example of a photoelectrochemical process. In photoelectrochemical devices where photoelectrodes are backside irradiated, the materials used in the anode or cathode must allow the penetration of the radiation with the desired wavelength. The radiation must reach and excite a photocatalyst material to a state with higher chemical potential, thus creating an electrical potential difference.

[0009] In most commercial electrochemical cells, mass transfer is fully dependent on diffusion and convection. This is due to the distance between the electrodes that in general is short enough to avoid Ohmic losses caused by the impedance of an applied electrolyte to current flow. Most commercial technologies introduce flow obstacles to enhance interfacial contact and thus boost mass transfer. However, in laminar flow conditions, the introduction of flow obstacles only changes the cross-section of the different streams, but it fails at creating convection with the associated enhancement in mass transfer.

[0010] A mixing plate composed of a reaction fluid distributor with a network of cylindrical chambers interconnected by prismatic channels of micro or meso dimensions promotes chaotic convection in the electrochemical device to enhance mass transfer at laminar flow regimes. In a mixing plate of this type, the chaotic flow patterns boost the formation of diffusion interfaces and reduce boundary layers' thickness, resulting in a huge increase in mass transfer between two or more streams. This technical solution was first applied for fast chemical reactions. Recently, it was successfully used for heat transfer in highly exothermic systems.

[0011] These facts are described in order to illustrate the technical problem solved by the achievements of the present document.

GENERAL DESCRIPTION

[0012] Electrochemical devices that generate electrochemical reactions play a key role in a wide range of industry sectors. These devices are critical enabling technologies for renewable energy; energy management, conservation, and storage; pollution control/monitoring; and greenhouse gas reduction. Examples of processes that resort to electrochemical devices that generate electrochemical reactions include electrolysis of water to produce hydrogen; electroreduction of carbon dioxide into carbon-bearing fuels or chemical feedstock compounds, such as carbon monoxide, methane, formic acid, methanol, ethylene, and ethane; electrosynthesis of multiple organic value-added products; electrooxidation of contaminants in aqueous matrices; among others.

[0013] The electrochemical device of the present disclosure addresses the mass transfer constraints in the currently available electrochemical devices for reduction and oxidation reactions. Accordingly, the now disclosed electrochemical device presents an enhanced mass transfer, ultimately achieving higher efficiencies in generating one or more reduced products at the cathode and/or one or more oxidized products at the anode.

[0014] An aspect of the present disclosure relates to an electrochemical device comprising at least one reaction fluid distributor with a network for flowing at least one reaction fluid, wherein said reaction fluid distributor network comprises an array of chambers, each chamber being interconnected by at least two channels to at least two other chambers; and at least two electrodes, working as an anode and a cathode, to which electrical energy is provided to produce one or more chemical reactions; and at least one reaction fluid where charge-transferring reactions take place.

[0015] In an embodiment, the mixing plate of the electrochemical device acts exclusively as a reaction fluid distributor, and wherein the reaction fluid distributor network comprises cylindrical chambers interconnected by prismatic channels is imprinted or perforated in a plate.

[0016] In an embodiment, the mixing plate of the electrochemical device acts as both a reaction fluid distributor and an electrode, wherein the reaction fluid distributor network imprinted or perforated in a plate, for better results.

[0017] In an embodiment, the mixing plate of the electrochemical device acts as both a reaction fluid distributor and a current collector, and the reaction fluid distributor network imprinted in a conducting plate, for better results. [0018] In an embodiment, the electrochemical device comprises at least one end plate; preferably two end plates, each one paced at one end, to tighten and hold the other plates and seal the electrochemical device, for better results.

[0019] In an embodiment, the reaction fluids used in the electrochemical device are introduced and removed through inlet and outlet ports positioned in the network or end plates, for better results.

[0020] In an embodiment, the end plate of the electrochemical device comprises a window for irradiation of the electrode plate, for better results.

[0021] In an embodiment, the electrochemical device comprises single or multiple compartments delimited by a separator, typically a membrane or diaphragm, for better results.

[0022] In an embodiment, the electrochemical device further comprises at least one heat exchanger, for better results.

[0023] In an embodiment, the heat exchanger of the electrochemical device is an integrated heat exchanger within or attached to the plates, for better results.

[0024] In an embodiment, the electrochemical device further comprises at least one gasket or at least one insulating layer between the reaction fluid distributor plates and adjacent plates, allowing fluid flow while providing electrical insulation, for better results.

[0025] In an embodiment, the gaskets of the electrochemical device are perforated to enable fluid flow while insulating the reaction fluid distributor plate, for better results.

[0026] In an embodiment, at least one reaction fluid flows within the electrochemical device. The reaction fluid can consist of one reactant orvarious reactants, one or various electrolytes, or a mixture of one or more reactants and one or more electrolytes.

[0027] In an embodiment for better results, each chamber is connected to four channels disposed in 90° angles. [0028] In an embodiment for better results, at least two channels are prismatic channels. Preferably, the channels comprise a prismatic configuration in micro or meso dimensions.

[0029] In an embodiment for better results, the chamber has a cylindric configuration.

[0030] In an embodiment for better results, the electrochemical device further comprises gaskets between the various components to avoid leakages, and, in some cases, the gaskets can also be used to maintain electrical insulation between electrodes to prevent electrical shortcuts. Alternatively, electrical insulation can be provided by placing electrically insulating layers between the electrodes. Gaskets and electrically insulating layers can have distinct configurations and be made of distinct materials.

[0031] In an embodiment for better results, the electrochemical device further comprises at least one heat exchanger for thermal stabilization of reaction fluids inside the device, generally through the circulation of thermal fluid.

[0032] In an embodiment for better control of the reaction potential, the electrochemical device further comprises at least one reference electrode.

[0033] In an embodiment for better results, the electrochemical device further comprises at least one end plate, ideally two, each one paced at one end Said end plates tighten and hold the other plates and the various components together and can also be used to host the hydraulic connections for the fluids (reaction or thermal) entering and leaving the device. The use of end plates may always be considered although it is not mandatory.

[0034] In an embodiment for better results, at least one end plate and/or the reaction fluid distributor network have at least one inlet port and one outlet port, for feeding and leaving one or more reaction fluids. Inlet ports can be placed at the top of the plates/networks and outlet ports can be placed at the bottom of the plates/networks, but their position can be changed, permitting the reaction fluid to flow downwards or upwards.

[0035] In an embodiment for photoelectrochemical reactions, at least one end plate comprises a window for irradiation of one electrode plate. [0036] In an embodiment for better results, the electrochemical device further comprises at least one separator.

[0037] In an embodiment, the electrodes can have distinct configurations: a non-porous or a porous plate; a flat (2D) plate or a plate with printed or carved three-dimensional channels (3D); and an opaque plate, a transparent plate, or a translucent plate.

[0038] Another aspect of the present disclosure relates to an electrochemical cell stack comprising a plurality of electrochemical devices (unit) described in the present disclosure.

[0039] In an embodiment, if the current collector is not built into the electrode, one or more external current collector plates should be considered to ensure large current loads with minimal energy losses and enable using catalyst materials with lower conductivity.

[0040] In an embodiment, gas diffusion layers not incorporated in the electrodes can be considered.

[0041] In an embodiment, whenever a reaction fluid distributor plate includes said network of cylindrical chambers interconnected by prismatic channels, the reaction fluid distributor plate is referred to as a mixing plate. Whenever a reaction fluid distributor plate includes a network of any other shape it is referred to as a non-specific reaction fluid distributor plate.

[0042] In an embodiment, the mixing plates and non-specific reaction fluid distributor plates can act exclusively as reaction fluid distributors, aiming solely at flowing and mixing one or more reaction fluids, being made of insulating materials; can act concomitantly as reaction fluid distributors and electrodes, aiming at flowing and mixing one or more reaction fluids and working as active electrical conductors to carry out reactions, being made of active conducting materials; or can act concomitantly as reaction fluid distributors and current collectors, aiming at flowing and mixing one or more reaction fluids and simultaneously ensuring large current loads with minimal energy losses, and enabling the use of catalyst materials with lower conductivity, being made of conducting materials. [0043] In an embodiment, electrodes working as cathodes and anodes can comprise a catalyst-supporting substrate, where the catalyst uses electric or photo-electric power for catalysing a given reaction or various reactions; or can be composed of a set of different layers.

[0044] In an embodiment, the layers that compose an electrode can include a supporting substrate layer; a catalyst layer; none or one current collector; a gas diffusion layer, which enables the mass transport of reaction fluids to the catalyst layer; among other layers.

[0045] In an embodiment, the electrochemical device may concern either an undivided device or a divided device. Said divided device uses a physical separator interposed between the two electrodes, giving rise to a cathodic fluid or fluids flowing through one compartment and an anodic fluid or fluids flowing through the other compartment.

[0046] In an embodiment, separators are typically membranes or diaphragms. Besides dividing the electrochemical device into two compartments, said separators prevent direct electrical contact (shortcut) between the electrodes and pose a barrier to transporting molecular and/or ionic species between the compartments.

[0047] In an additional embodiment, gas diffusion layers not incorporated in the electrodes can be considered.

BRI EF DESCRIPTION OF TH E DRAWINGS

[0048] The following figures provide preferred embodiments for illustrating the disclosure and should not be seen as limiting the scope of the invention.

[0049] Figure 1: Schematic representation of a stacked view of an embodiment of the electrochemical device.

[0050] Figure 2: Schematic representation of an embodiment of the mixing plate of the electrochemical device.

[0051] Figure 3: Schematic representation of the planar top and bottom views of the different layers in an embodiment of the electrochemical device. [0052] Figure 4: Schematic representation of the planar top and bottom views of the different layers in an embodiment of the electrochemical device.

[0053] Figure 5: Schematic representation of the planar top and bottom views of the different layers in an embodiment of the electrochemical device.

[0054] Figure 6: Schematic representation of the planar top and bottom views of the different layers in an embodiment of the electrochemical device.

[0055] Throughout the figures indicated above, the following elements are indicated with the respective references:

1 - end plate;

2 - mixing plate made of a conducting material working simultaneously as an electrode with an imprinted network;

3 - separator;

4 - inlet/outlet port;

5 - channels for inlet/outlet connection;

6 - network of cylindrical chambers interconnected by prismatic channels;

7 - chamber;

8 - channel;

9 - electrode plate;

10 - electrically insulating layer;

11 - window;

12 - inlet port for a first fluid;

13 - inlet port for a second fluid;

14 - outlet port for first and second fluids;

15 - perforated chamber;

16 - external power circuit;

17 - outlet port for a first fluid;

18 - outlet port for a second fluid;

19 - mixing plate made of any material with a perforated network;

20 - ion-exchange membrane; 21 - mixing plate made of a conducting material working simultaneously as a current collector with an imprinted network;

22 - anode catalyst layer;

23 - cathode catalyst layer;

24 - proton exchange membrane;

25 - anode gas diffusion layer;

26 - cathode gas diffusion layer;

27 - inlet port for anodic fluid;

28 - outlet port for anodic fluid;

29 - outlet port for cathodic fluid;

30 - inlet port for cathodic fluid.

DETAILED DESCRIPTION

[0056] The present disclosure relates to an electrochemical device with surprisingly enhanced mass transfer and respective uses. The device of the present disclosure comprises a reaction fluid distributor network with an array of chambers interconnected by multiple channels, and at least two electrodes, an anode and a cathode, to which electrical energy is supplied to facilitate chemical reactions in a surprisingly and unexpected manner.

[0057] It is disclosed an electrochemical device comprising at least one reaction fluid distributor with a network for flowing one or more reaction fluids, wherein said reaction fluid distributor network comprises an array of chambers, each chamber being interconnected by at least two channels to at least two other chambers; and at least two electrodes, an anode and a cathode, to which electrical energy is provided to produce one or more chemical reactions.

[0058] In embodiments of the present disclosure, the reaction fluid distributor network comprising an array of chambers, each chamber being interconnected by at least two channels to at least two other chambers, is imprinted or perforated in a plate and preferentially has cylindrical chambers interconnected by prismatic channels, as illustrated in Figure 2. [0059] In an embodiment, when the mixing plate acts exclusively as a reaction fluid distributor, said network of chambers interconnected by channels is imprinted or perforated in a plate of any material. An example of a mixing plate acting exclusively as a reaction fluid distributor with a perforated network is illustrated in the embodiment of Figure 4 (19). When the mixing plate acts simultaneously as a reaction fluid distributor and an electrode, said network of chambers interconnected by channels is imprinted in an active and conducting plate, as illustrated in the embodiment of Figure 3 (2). When the mixing plate acts concomitantly as a reaction fluid distributor a nd a current collector, said network of chambers interconnected by channels is imprinted in a conducting plate, as illustrated in the embodiments provided in Figures 5 and 6 (21).

[0060] In an embodiment, one or more reaction fluids, such as liquid or gas, should be fed to each fluid distributor plate (mixing plate or non-specific reaction fluid distributor plate). Said reaction fluids can comprise a reactant or a mixture of reactants; an electrolyte or a mixture of electrolytes, which refer to a medium containing ions; or a mixture of one or more reactants and one or more electrolytes. In an embodiment, said reaction fluids can be referred to as catholyte if in contact only with the cathode, anolyte if in contact only with the anode, or catholyte and anolyte simultaneously if in contact with the anode and the cathode.

[0061] In an embodiment, the initial reaction fluids are supplied to the reaction fluid distributor network through one or more inlet ports positioned in the network itself and/or in the end plates of the electrochemical device. The final reaction fluids resulting from the process leave the electrochemical device through one or more outlet ports positioned in the network itself and/or in the end plates of the electrochemical device. The inlet/outlet configuration ensures the complete injection of reactants and/or electrolytes over the reaction fluid distributor network, and the complete collection of reaction products and/or electrolytes from said reaction fluid distributor network. The inlets and outlets can be placed along the said micro or mesostructured network or along other flow paths enabling multi-stage injection or collection of reactants and products. [0062] In an embodiment, the electrochemical device concerns either a singlecompartment device or a device with multiple compartments. Said compartmentalized device uses a separator, either a membrane or diaphragm, interposed between the two electrodes and the cathodic fluid or fluids and the anodic fluid or fluids flow through different compartments. Among separators, ion-exchange membranes are the most popular, which comprise semi-permeable membranes that transport some ions while blocking other ions or neutral molecules.

[0063] In an embodiment, the electrode plate can be selected from a list consisting of a non-porous plate or porous plate; a flat (2D) plate or a plate with printed or carved three-dimensional channels (3D); an opaque plate, a transparent plate, or a translucent plate; or their combinations. While non-porous electrode plates are smooth and impermeable so fluids cannot move through them, porous electrode plates are composite solids containing interconnected void space that can be filled by the fluids. Gas diffusion electrodes and membrane assembly electrodes are porous electrode plates, alongside others. In an embodiment, the 3D electrode plates have imprinted channels or are porous enabling flow-through, whose effective surface area is greater than their planar area and are obtained by depositing structured materials on the plate or by using porous materials such as reticulated, meshed, fiber, or felt materials. While opaque electrode plates block the passage of radiation, transparent and translucent electrodes enable radiation passage. Transparent and translucent electrode plates are commonly referred to as photoelectrodes and typically comprise a transparent material such as glass coated with a transparent or translucent electrical conductor, which is in turn coated with a photocatalyst.

[0064] In an embodiment, the electrochemical device can include heat exchangers. These heat exchangers can be flow channels engraved in the back of the non-specific reaction fluid distributor plates, electrodes, and current collector plates, mixing plates acting exclusively as reaction fluid distributor plates, mixing plates acting concomitantly as reaction fluid distributor plates and electrodes, and mixing plates acting concomitantly as reaction fluid distributor plates and current collector plates. Alternatively, the heat exchangers can encompass an extra plate or end plate that can be stacked in the electrochemical device adjoined to non-specific reaction fluid distributor plates, electrodes, and current collector plates, mixing plates acting exclusively as reaction fluid distributor plates, mixing plates acting concomitantly as reaction fluid distributor plates and electrodes, and mixing plates acting concomitantly as reaction fluid distributor plates and current collector plates.

[0065] In an embodiment, the stresses to lock and seal the stack of plated in the electrochemical device are typically applied on the end plates that can be opaque, totally covering the other components, or can include a window for the irradiation of one or two electrode plates, if photoelectrodes are being applied.

[0066] In an embodiment, one or more relevant gaskets or electrically insulating layers can be applied in the contact of the reaction fluid distributor plates with adjacent plates. Preferably, said gaskets are perforated to enable fluid flow while insulating the reaction fluid distributor plate.

[0067] In an embodiment, one reference electrode, if in the presence of a single compartment electrochemical device, and one or two reference electrodes, one on the cathode side and the other on the anode side, if in the presence of a divided electrochemical device, can be applied. Reference electrodes have a stable and well- known electrode potential to accurately control the potential of a working electrode. Said reference electrodes can have any configuration and the design of the electrochemical device can be modified to fit the reference electrodes.

[0068] In an embodiment, the electrochemical device has a modular structure that enables the stacking of multiple electrochemical devices associated in series or parallel. The number of said modules can be adjusted to regulate the production rate.

[0069] In an embodiment, the electrochemical device requires a power supply and external circuit to operate. The power supply converts electric current to voltage, current, and frequency to power the load. The power supply is not of a specific type and may be of any form.

[0070] In an embodiment, the electrochemical device may contain reaction regions where electrochemical reactions preferentially proceed. [0071] In an embodiment, the various elements of said electrochemical device should be constructed using materials adequate to the reactants and products involved.

[0072] The present disclosure enables different embodiments that are application specific. The embodiments of this invention are examples of construction layouts, and particular layouts for specific applications that do not cover all the possibilities of implementation.

[0073] Figure 5 illustrates a planar representation of an embodiment of the electrochemical device. Top and bottom views of each layer are represented. The different layers of said electrochemical device are held in a stacked way. In this embodiment, an electrochemical device for proton electrolyte membrane (PEM) water electrolysis to produce hydrogen gas is illustrated as an example. The PEM water electrolysis is used as a non-exclusive embodiment of this electrochemical device for producing hydrogen gas. Other embodiments regarding the electrolysis process can be used, such as anion exchange membrane (AEM) water electrolysis, alkaline water electrolysis (AWE), solid oxide electrolysis (SOE), microbial electrolysis cells (MEC), and sulfur dioxide depolarized water electrolysis (SDE) as a stage of the Westinghouse Cycle.

[0074] In the embodiment illustrated in Figure 5, mixing plates (21) have the network of cylindrical chambers interconnected by prismatic channels (6) imprinted in one face, are made of conducting material, and operate simultaneously as fluid distributor plates and current collector plates. In such embodiment, one mixing plate (21) is placed on the anode side and one mixing plate (21) is placed on the cathode side. The networks of cylindrical chambers interconnected by prismatic channels (6) are facing each other. One anode catalyst layer (22) is making electrical contact with the mixing plate on the anode side and one cathode catalyst layer (23) is making electrical contact with the mixing plate on the cathode side. Reference numeral (24) illustrates a proton exchange membrane, but other membranes in other electrolysis types, such as anion exchange membrane, diaphragm, solid ceramic membrane, bipolar membrane, charge-mosaic membrane, among others, could have been equally illustrated. In some applications, such as SOE, the electrochemical device can be membrane-free. Said proton exchange membrane (24) is sandwiched between catalyst layers (22) and (23). Reference numeral (25) denotes an anode gas diffusion layer and reference numeral (26) denotes a cathode gas diffusion layer. Each said gas diffusion layer (25) or (26) is sandwiched between a catalyst layer (22) or (23) and a mixing plate (21).

[0075] In the embodiment illustrated in Figure 5, the anode catalyst layer (22) is selected from a list consisting of iridium and ruthenium mono-metallic catalysts, alloy catalysts, oxide catalysts, perovskite oxides, among others, or their combinations. Said materials permit water electrochemical oxidation to form oxygen, i.e., the oxygen evolution reaction (OER). In this embodiment, the cathode catalyst layer (23) is selected from a list consisting of platinum-based catalysts, transition metal dichalcogenides, nickel- activated transition metal carbides, etc., or their combinations. Said materials allow water electrochemical reduction to produce hydrogen, i.e., the hydrogen evolution reaction (HER). The proton exchange membrane (24) typically comprises perfluorosulfonic acid polymer membranes, such as sulfonated tetrafluoroethylene based fluoropolymer-copolymer, long side chain - per-fluorinated sulfonic acid, fluorinated, and perfluorosulfonic acid, although other proton exchange membrane materials can be used. In this embodiment, gas diffusion layers (25) and (26) are made of conductive porous materials and enhance reactants and products diffusion. In this embodiment, electrode catalyst layers (22) and (23), proton exchange membrane (24), and gas diffusion layers (25) and (26) constitute a membrane electrode assembly (MEA). It is possible to omit gas diffusion layers (25) and (26), giving rise to a catalyst coated membrane (CCM).

[0076] In the embodiment illustrated by Figure 5, the configuration relates to a divided cell, with proton exchange membrane (24) establishing the separation of anodic and cathodic compartments. An anodic fluid composed of water in the liquid phase is pumped to the micro or mesostructured reaction fluid distributor network (6) that is imprinted in the mixing plate (21) on the anode side. Said anodic fluid is typically fed upwards via a single bottom inlet port (27) flowing towards a single top outlet port (28). Said inlet and outlet ports (27) and (287) have ramifications that transport the fluid to mixing chambers of the first row of the cathodic micro or mesostructured reaction fluid distributor network (6). Alternatively, the anodic fluid can be fed directly to the various mixing chambers of the first row of the imprinted cathodic micro or mesostructured reaction fluid distributor network (6).

[0077] In the embodiment of Figure 5, the anodic fluid typically entering the inlet port (27) flows through the anodic micro or mesostructured reaction fluid distributor network (6) and is transferred to the anode catalyst layer (22), crossing the hydrophilic structure of the anode gas diffusion layer (25). Oxidation of said water to oxygen gas, protons, and electrons then occurs at the anode catalyst layer (22) by applying a bias potential. A major part of said oxygen flows through the hydrophobic structure of the anode gas diffusion layer (22), reaching the anodic micro or mesostructured reaction fluid distributor network (6) placed in the anodic mixing plate (21) on the anode side and exiting the electrochemical device typically by a top outlet port (28) together with an excess of water. A minor part of said oxygen permeates across the proton exchange membrane (24) to the cathode side, crossing the cathode catalyst layer (23) and the cathode gas diffusion layer (26), thereby achieving the cathodic micro or mesostructured reaction fluid distributor network (6) imprinted in the mixing plate (21) on the cathode side, and exiting the electrochemical device typically by the top outlet port (29). The generated protons cross the proton exchange membrane (24) to the cathode catalyst layer (23). The released electrons exit from the anode catalyst layer (22) to the cathode catalyst layer (23) through an external power circuit (16).

[0078] In the embodiment illustrated by Figure 5, protons and electrons reaching the cathode catalyst layer (23) combine to form hydrogen gas. Said hydrogen gas flows through the cathode gas diffusion layer (26), reaching the cathodic micro or mesostructured reaction fluid distributor network (6) imprinted in the cathodic mixing plate (21). A major part of said hydrogen gas leaves the electrochemical device, typically via the top outlet port (29), together with the traces of generated oxygen. Alternatively, an outlet can be placed in the mixing chambers of the last row of the cathodic micro or mesostructured reaction fluid distributor network (6). A minor part of the hydrogen gas permeates through the proton exchange membrane (24) to the anode side, crossing the anode catalyst layer (22) and the anode gas diffusion layer (25), thereby reaching the anodic micro or mesostructured reaction fluid distributor network (6) and exiting the electrochemical device typically by the top outlet port (28) together with the oxygen produced in the anode.

[0079] In the embodiment represented in Figure 5, in addition, a part of the anodicfluid, such as water, can flow through the proton exchange membrane (24) from the anode side to the cathode side and then back from the cathode side to the anode side, crossing the catalyst layers (22) and (23) and the gas diffusion layers (25) and (26), ultimately attaining the micro or mesostructured reaction fluid distributor networks (6) and exiting the electrochemical device typically by top outlets (28) and (29) together with the other compounds, such as oxygen, excess of water and traces of hydrogen gas in the anode side; hydrogen gas and traces of oxygen in the cathode side. Water is transferred from the anode side to the cathode side due to water concentration difference and electroosmotic drag across the proton exchange membrane (24). Water is transferred from the cathode side to the anode side due to hydraulic pressure.

[0080] In the embodiment illustrated by Figure 5, temperatures from 20 °C to 80 °C, pressures from 1 atm to 50 atm, and current density from 0.6 A/cm2 to 9 A/cm2 are typically employed since the process regards proton exchange membrane (PEM) water electrolysis, but other operating conditions can be used

[0081] In the embodiment of Figure 5, the use of one end plate at each end should always be considered to provide support and safety to the electrochemical device, although they are not mandatory.

[0082] In the embodiment illustrated by Figure 6, it is possible to see a planar representation of a second possible embodiment of the electrochemical device. This electrochemical device is similarto the first embodiment illustrated in Figure 5, covering the proton exchange (PEM) water electrolysis to produce hydrogen gas, but the cathode side is equipped with a cathodic inlet (30) for feeding the cathodic fluid, that is liquid water, to the imprinted cathodic micro or mesostructured reaction fluid distributor network (6) at the mixing plate (21) on the cathode side. Typically, said cathodic inlet (30) corresponds to a single inlet positioned at the bottom of the imprinted cathodic micro or mesostructured reaction fluid distributor network (6) and splits into ramifications of any shape that transport the fluid to chambers of the first row of the cathodic micro or mesostructured reaction fluid distributor network (6). Alternatively, the cathodic fluid, such as water, can be fed directly to the various mixing chambers of the first row of the cathodic micro or mesostructured reaction fluid distributor network (6). Said cathodic fluid is typically fed upwards, but it can also be fed downwards by positioning the cathodic fluid inlet at the top of the imprinted cathodic micro or mesostructured reaction fluid distributor network (6) and the cathodic fluid outlet in the bottom of the imprinted cathodic micro or mesostructured reaction fluid distributor network (6).

[0083] In the embodiment of Figure 6, not only the water fed to the cathode flows from the cathode inlet (30) to the cathode outlet (29) but also additional amounts of water flow due to the pressure difference across the proton exchange membrane (24) from the cathode to anode, also crossing the catalyst layers (22) and (23) and the gas diffusion layers (25) and (26).

[0084] In Figure 1, it is illustrated an embodiment of a generic electrochemical device with a divided configuration, in a stacking example, comprising two mixing plates (2) with imprinted networks of cylindrical chambers interconnected by prismatic channels

(6) working simultaneously as reaction fluid distributor plates and electrode plates. The networks of cylindrical chambers interconnected by prismatic channels (6) of the two mixing plates (2) are facing each other. A separator (3) is placed between the two said mixing plates (2). The different layers of the electrochemical device are held in a stacked way with the help of two end plates (1). End plates (1) and mixing plates (2) have at least one inlet port and one outlet port, (4), for feeding and leaving one or more reaction fluids.

[0085] In Figure 2, it is illustrated a detail of an embodiment of the mixing plate (2) composed of a micro or mesostructured network that consists of cylindrical chambers

(7) interconnected by prismatic channels (8) where the reaction fluid circulates. The representation illustrates a single inlet port (4) for feeding a reaction fluid to the micro or mesostructured reaction fluid distributor network (6) and a single outlet port (4) from said micro or mesostructured reaction fluid distributor network (6). Furthermore, said single inlet/outlet ports (4) are connected to the first row of chambers of said micro or mesostructured reaction fluid distributor network (6) by channels (8) with hierarchical binary ramifications. However, multiple inlet/outlet ports (4) can be used instead of single inlet/outlet ports (4) and, in this case, different reaction fluids can be fed to the micro or mesostructured reaction fluid distributor network (6). Furthermore, the connection between inlet/outlet ports to said micro or mesostructured reaction fluid distributor network (6) can be done using channels (8) of any shape or the reaction fluid can be fed directly to the various mixing chambers (7) of the first row of the micro or mesostructured reaction fluid distributor network (6). Additionally, inlets and outlets can be placed along the micro or mesostructured reaction fluid distributor network (6), aiming at the gradual injection of substrate or reactants or collection of reaction products. The reaction fluids can flow upwards or downwards.

[0086] In Figure 3 is illustrated a planar view of the layers of a possible embodiment of the electrochemical device with an undivided configuration. One end plate (1) can have a window (11) for irradiation of photoelectrodes. The electrochemical device has one mixing plate (2) with the micro or mesostructured reaction fluid distributor network (6) imprinted in an active face working simultaneously as fluid distributor plate and electrode plate. The electrode plate (9) has no engraved networks/circuits. Typically, two reaction fluids are supplied to the micro or mesostructured reaction fluid distributor network (6) through two inlet ports, (12) and (13), placed in the end plate (1); and the reaction fluid exits the device through a single outlet port (15). Inlets can be placed at the top and inlets at the bottom of the plates, but their position can be changed, permitting the reaction fluid to flow downwards or upwards. The micro or mesostructured reaction fluid distributor network (6) in the mixing plate (2) faces an active side of the electrode plate (9) and said plates, (2) and (9), are separated by a moveable or fixed electrically insulating layer (10) that does not cover at least part of the micro or mesostructured reaction fluid distributor network (6), with the network's chambers (7) being typically uncovered. Said electrically insulating layer (10) prevents metallic electrical contact between the mixing plate (2) and the electrode plate (9). A voltage is applied between the mixing plate (2) and the electrode plate (9) and electrons are transferred through an external power circuit (16). [0087] In Figure 4 is illustrated a planar view of the layers of a possible embodiment of the electrochemical device with a divided configuration. The electrochemical device comprises two mixing plates (19) made of insulating material with the micro or mesostructured reaction fluid distributor network (6) perforated. Said mixing plates (19) act exclusively as fluid distributor plates. Each mixing plate (19) is alongside an active face of an electrode plate (9). An ion-exchange membrane (20) is placed between said mixing plates (19). Said ion-exchange membrane (20) is responsible for separating the anodic and cathodic compartments. Typically, a different reaction fluid is supplied to each micro or mesostructured reaction fluid distributor network (6) through single inlet ports (12) and (13) and the reaction fluids leave the device through single outlet ports (17) and (18). In an embodiment, inlets (12) and (13) are placed at the bottom and outlets (17) and (18) at the top of the plates, but this positioning can be reversed. A voltage is applied between the electrode plates (9) and electrons are transferred through an external power circuit (16).

[0088] The term "comprising" whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0089] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof.

[0090] The above-described embodiments are combinable.

[0091] The following claims further set out particular embodiments of the disclosure.

Claims

C L A I M S

1. An electrochemical device for one or more chemical reactions comprising: at least two electrodes, an anode and a cathode; at least one reaction fluid distributor network for flowing one or more reaction fluids, wherein said reaction fluid distributor network comprises an array of chambers, each chamber being interconnected by at least two channels to at least two other chambers.

2. The electrochemical device according to the previous claim, wherein each chamber is connected to four channels disposed in 90° angles.

3. The electrochemical device according to any of the previous claims, comprising a mixing plate acts exclusively as a reaction fluid distributor, and wherein the reaction fluid distributor network comprises cylindrical chambers interconnected by prismatic channels imprinted or perforated in a plate.

4. The electrochemical device according to any of the previous claims, comprising a mixing plate that acts as both a reaction fluid distributor and an electrode, with the reaction fluid distributor network imprinted in an active conducting plate.

5. The electrochemical device according to any of the previous claims, wherein the mixing plate acts as both a reaction fluid distributor and a current collector, with the reaction fluid distributor network imprinted in a conducting plate.

6. The electrochemical device according to any of the previous claims, comprising at least one end plate; preferably two end plates, each one paced at one end, to tighten and hold the other plates and seal the electrochemical device.

7. The electrochemical device according to any of the previous claims, wherein the one or more reaction fluids are introduced and removed through inlet and outlet ports positioned in the network or end plates.

8. The electrochemical device according to the previous claim, wherein the end plate comprises a window for irradiation of the electrode plate.

9. The electrochemical device according to any of the previous claims, comprising single or multiple compartments delimited by a separator, typically a membrane or diaphragm.

10. The electrochemical device according to any of the previous claims, further comprising at least one heat exchanger.

11. The electrochemical device according to the previous claim, further comprising a heat exchanger, wherein said heat exchanger is an integrated heat exchanger within or attached to the plates.

12. The electrochemical device according to the previous claim, further comprising at least one gasket or at least one insulating layer between the reaction fluid distributor plates and adjacent plates, allowing fluid flow while providing electrical insulation.

13. The electrochemical device according to the previous claim, wherein the at least one gasket is perforated to enable fluid flow while insulating the reaction fluid distributor plate.

14. The electrochemical device according to any of the previous claims, wherein the at least two channels are prismatic channels.

15. The electrochemical device according to any of the previous claims, wherein the channels comprise a prismatic configuration in micro or meso dimensions.

16. The electrochemical device according to any of the previous claims, wherein the chamber comprises a cylindric configuration.

17. The electrochemical device according to any of the previous claims, further comprising at least one reference electrode.

18. The electrochemical device according to any of the previous claims, further comprising a separator, preferably a membrane or a diaphragm.

19. The electrochemical device according to any of the previous claims, wherein the reaction fluid distributor network comprises at least one inlet/outlet port.

20. The electrochemical device according to any of the previous claims, wherein the reaction fluid comprises one or more reactants, one or more electrolytes, or combinations thereof.

21. The electrochemical device according to any of the previous claims, wherein the electrodes comprise a non-porous plate or a porous plate; a flat (2D) plate or a plate with printed or carved three-dimensional channels (3D); and an opaque plate, a transparent plate, or a translucent plate; or combinations thereof.

22. The electrochemical device according to any of the previous claims, wherein the electrodes can be composed of distinct layers, such as a supporting substrate layer; a catalyst layer; a current collector; a gas diffusion layer; among others.

23. The electrochemical device according to any of the previous claims, further comprising a current collector if the current collector is not built into the electrode.

24. The electrochemical device according to any of the previous claims, further comprising a gas diffusion layer if the gas diffusion layer is not built into the electrode.

25. An electrochemical cell stack comprising a plurality of electrochemical devices according any of the previous claims 1-24 in layers.