Device and method for examining electrochemical processes

Abstract

The invention relates to a device for examining electrochemical processes in a plurality of electrochemical reactor units. The device has a reaction device with a plurality of electrochemical reactor units, a fluid supply unit, and an electroanalytical measuring device, wherein each of the electrochemical reactor units of the reaction device is designed to carry out a respective electrochemical reaction, and wherein each of the electrochemical reactor units has a plurality of electrodes which are designed to be connected to the electroanalytical measuring device. The fluid supply unit is designed to supply each of the plurality of electrochemical reactor units with fluids for carrying out the electrochemical reaction, and the electroanalytical measuring device is designed to examine electrochemical processes occurring in the plurality of electrochemical reactor units when the respective electrochemical reaction is carried out. At least one of the electrochemical reactor units has a plurality of components, wherein the reactor unit is composed of the plurality of components, and wherein an impedance of each of the plurality of components is known, and the device is designed to carry out a characterisation of the electrochemical processes in the plurality of reactor units, wherein, during the characterisation, measured values of the respective reactor unit are compared with measured values of the reactor unit composed of the components with known impedances.

Description

[0001] Device and method for investigating electrochemical processes

[0002] Field of the invention

[0003] The invention relates to a device for investigating electrochemical processes in a plurality of electrochemical reactor units, and to a method for investigating electrochemical processes in a plurality of electrochemical reactor units.

[0004] Background of the invention

[0005] In electrochemical processes, the conversion and product yield are correlated with the energy efficiency with which the starting materials are converted into the desired products. Energy efficiency is high when the electrical resistances within a reaction system are low.

[0006] The development and optimization of electrochemical processes is crucial for achieving the transformation of industry so that processes can be operated with electricity generated from renewable energy sources. The optimization of electrochemical processes offers significant savings potential for processes that currently require high energy inputs or that cannot be operated profitably due to their high energy inputs. New and improved processes therefore offer significant potential for reducing carbon dioxide emissions compared to current operations.

[0007] When developing electrochemical production processes, it is therefore advisable to first conduct laboratory-scale investigations to identify the process parameters to be used for the industrial production process. To conduct laboratory-scale investigations, a test rig is preferably used, which can test a large number of experimental parameters in order to identify those process parameters with low electrical resistance. The structural design of the test rigs and the reactors used therein, as well as the accuracy of process parameter control, are important. Preferably, systems are used in which a certain number of reactors are arranged in parallel and can be operated at least partially simultaneously.It is preferred that the reactors arranged in parallel are operated at test settings that differ from one reactor to the next with regard to the process parameters.

[0008] In the field of high-throughput research, there is a continuous need to conduct tests and examinations more quickly and efficiently in order to replicate technical processes with high accuracy in the laboratory. Large amounts of data and high measurement accuracy can help reduce the number of tests that need to be conducted at pilot plant scale.

[0009] This saves time, costs and energy in product development.

[0010] The inventors of the present invention found that it would be advantageous to provide an improved apparatus and method for investigating electrochemical processes in a plurality of electrochemical reactor units in order to be able to vary the process parameters on a large number of functional elements simultaneously or in close temporal proximity.

[0011] Description of the invention

[0012] An object of the invention is therefore to provide an improved device and a method for investigating electrochemical processes, with the aid of which process-related and material-specific optimizations can be carried out simultaneously or in close temporal proximity on a large number of functional elements by varying the process parameters.

[0013] The object is achieved by the subject matter of the independent claims. Advantageous developments of the invention are specified in the dependent claims, the description, and the accompanying figures.

[0014] The described embodiments apply equally to the device for investigating electrochemical processes in a plurality of electrochemical reactor units, as well as to the method for investigating electrochemical processes in a plurality of electrochemical reactor units. Synergistic effects can arise from various combinations of the embodiments, even if they are not described in detail.

[0015] Furthermore, it should be noted that all method-related embodiments of the present invention can be carried out in the described order of steps. Nevertheless, this need not be the only possible or required order of steps in the method. The methods described herein can be carried out in a different order of the disclosed steps without deviating from the corresponding method embodiment, unless expressly stated otherwise below.

[0016] The invention relates to a device and a method for conducting electrochemical processes, with the aid of which the development of electrochemical processes is improved and accelerated compared to the methods known from the prior art. The device can comprise a group of electrochemical reactors arranged in parallel, which have the same or a different configuration and which can be arranged interchangeably within the device. The device preferably comprises a program controller, a database, and an analysis unit.The electrochemical reactor units are constructed from components or components according to a modular principle, whereby at least some of the components or components can be designed to be interchangeable, so that when carrying out the process, different components and components can be examined or those components and components which show signs of aging or wear can be replaced.

[0017] According to a first aspect of the invention, a device for investigating electrochemical processes in a plurality of electrochemical reactor units is proposed.The device comprises a reaction device with a plurality of electrochemical reactor units, a fluid supply unit, and an electroanalytical measuring device, wherein each of the electrochemical reactor units of the reaction device is designed to carry out a respective electrochemical reaction, wherein each of the electrochemical reactor units has a plurality of electrodes which are designed to be connected to the electroanalytical measuring device, wherein the fluid supply unit is designed to supply each of the plurality of electrochemical reactor units with fluids for carrying out the electrochemical reaction, and wherein the electroanalytical measuring device is designed to investigate electrochemical processes occurring in the plurality of electrochemical reactor units when carrying out the respective electrochemical reaction.At least one of the electrochemical reactor units has a plurality of components, wherein the reactor unit is composed of the plurality of components, and wherein an impedance of each of the plurality of components is known, and the device is designed to carry out a characterization of the electrochemical processes in the plurality of reactor units, wherein during the characterization, measured values ​​of the respective reactor unit are compared with measured values ​​of the reactor unit composed of the components with known impedances.

[0018] In electrochemical processes, the conversion and product yield are correlated with the energy efficiency with which the starting materials are converted into the desired products. Energy efficiency is high when the electrical resistances within a reaction system are low.

[0019] The present invention can support and advance the development of electrochemical production processes, as laboratory-scale investigations are initially conducted to identify those process parameters that can be used for the industrial production process in order to operate it economically. According to the invention, a device is preferably used to conduct the laboratory-scale investigations that is flexibly configurable and that allows the implementation and investigation of a large number of experimental parameters in order to identify those process parameters that enable a low electrical resistance of the reaction setup. The device according to the invention can preferably be operated with different reactor units, which can be selected depending on the type of electrochemical process to be investigated.Thus, a preferred embodiment of the device is one in which the reaction device has variable connection elements that can be switched on or off as needed, with the switching off being accomplished, for example, by closure elements on the supply lines or discharge lines. The individual electrochemical reactor units are registered in a program control so that the process units that serve to supply the cell elements can be adapted to the corresponding cell. The special feature here is that the device according to the invention is preferably a multifunctional device in which the reactor types and process sequences are stored in the program control, thus giving the user a wide range of options for developing or optimizing electrochemical processes.The electrochemical reactors are preferably constructed according to a modular system, where practical. This allows for the measurement of a wide variety of components and materials.

[0020] The electroanalytical measuring device can have one or more measuring units. A measuring unit can be connected sequentially to the reactor units via a multiplexer. Alternatively, each reactor unit can be equipped with its own separate measuring unit.

[0021] The invention thus also relates to a plurality of electrochemical reactor units, wherein at least one of the reactor units has a reference configuration which provides reference values ​​which are stored in a database or which are related to the values ​​from the other reactor units or which are both stored in a database and related to the values ​​from the other reactor units.

[0022] A reference configuration is achieved, for example, by a reactor unit comprising one or more components used in technical processes. The data quality of the data recorded in parallel from multiple reactor units is improved by operating a reactor unit with a reference configuration, as the data can be related to known process data.

[0023] An advantage of the parallel arrangement of multiple reactor units in combination with at least one reactor unit having a reference configuration is that reference data for experimental data can also be recorded simultaneously, thereby generating standardization or reference values ​​when implementing the process. This significantly improves the meaningfulness of the data compared to those achieved in a single arrangement, as the monitoring of process parameters is more precise, as the analyses can be performed almost simultaneously with identical online analyzers. In one embodiment of the invention, the device has a graphical user interface (GUI) for data evaluation.Advantageously, the device is designed to provide a user interface, preferably a graphical user interface or GUI, which enables a graphical representation of the data obtained during the simultaneous or nearly simultaneous execution of the method in the parallel reactor units. This can improve the visualization and evaluation of the data. Preferably, the evaluation method has an algorithm, in particular using artificial intelligence, which is capable of putting the recorded data and measured values ​​of the reactor units into context by comparing them. In particular, when characterizing the electrochemical processes in the reactor unit, an impedance of each of the components of the reactor unit is to be determined.

[0024] In one embodiment of the invention, the reaction device comprises at least two electrochemical reactor units, preferably at least four electrochemical reactor units, particularly preferably at least eight electrochemical reactor units, and / or each of the electrochemical reactor units of the reaction device has a 2-, 3-, or 4-electrode configuration.

[0025] Of importance are the structural design of the device and the reactors used therein, as well as the precision in controlling the process parameters. The present invention preferably relates to a device in which two or more reactor units are arranged in parallel, which can be operated at least partially simultaneously. With regard to the number of reactor units, it should be said that there can preferably be two or more reactor units. More preferably, the number of reactors arranged in parallel is at least four, furthermore preferably the number of reactors arranged in parallel is at least eight, and particularly preferably the number of reactors arranged in parallel is at least 16. For reasons of manageability, there may be an upper limit to the maximum number of reactor units.An upper limit may possibly arise due to space constraints or due to the desired degree of automation of the device.

[0026] In a preferred embodiment of the device according to the invention, the device is equipped with four reactor units arranged in parallel, such as electrochemical plate reactors, and thus forms a quadruple device. Two or more of the reactor units of this quadruple device can be combined or coupled into a system. This has the advantage that the individual modules are somewhat smaller and more compact, thus making operation easier. The four reactors arranged in parallel within a device can be operated under the same test conditions or under different test conditions. Different test conditions can be understood as meaning that at least one process parameter differs from one reactor to another.In one embodiment of the invention, the electroanalytical measuring device is designed to carry out a calibration measurement and / or a conditioning before characterizing the electrochemical processes in each of the plurality of electrochemical reactor units simultaneously or with a time delay.

[0027] In particular, in the case where the device comprises reactor units with gas diffusion electrodes (GDE), it is preferably provided to determine a resistance of the gas diffusion electrodes (GDE) used, which can be done computationally and by means of a graphical user interface in a graphical representation, advantageously for a large number of measurements taking place simultaneously.

[0028] In particular, an open-circuit OC measurement can be carried out for calibration. However, other measurements suitable for calibration can also be carried out, such as resistance measurements or gas conversion measurements and suitable process-related adjustments to establish a baseline. Baseline refers to a comparison basis that is selected so that the measurement objectives can be related to it. A resistance measurement is best achieved with a comparative resistance measurement at the beginning. For this purpose, the exact resistances of the modular cell system claimed here are determined before the actual measurement begins. The comparative OC measurement is particularly possible and useful with a parallel approach. A comparative measurement in a single-cell test bench would require the cell to be replaced after the measurement, since only one measuring station is available.Each exchange can lead to changes in the resistance at the contacts or surfaces due to changing contact conditions, which can disrupt calibration. Likewise, conditioning is only useful in a parallel system, and less so in a single-cell test bench, since cell surface charges are time-dependent. Conditioning before starting a parallel measurement should ideally also be performed in parallel.

[0029] In one embodiment of the invention, each of the electrochemical reactor units is selected from the group consisting of an electrochemical tank reactor, an electrochemical tube reactor, and an electrochemical plate reactor. The device according to the invention can thus comprise electrochemical reactor units, such as electrochemical tank reactors, electrochemical tube reactors, or electrochemical plate reactors. Other reactor types are also conceivable.

[0030] In one embodiment of the invention, the electrochemical plate reactor is selected from the group consisting of a fuel cell, an electrolysis cell, a redox flow battery, a battery, an electrochemical pump, and a capacitor. In a particularly preferred embodiment of the device for carrying out electrochemical processes, the reactor units can be electrochemical plate reactors designed as electrolysis cells. In one embodiment of the invention, the process parameters selected in each of the electrochemical reactor units of the reaction device are identical for the respective electrochemical reaction being carried out, or in each of the electrochemical reactor units of the reaction device, at least one process parameter differs from at least one other electrochemical reactor unit.This allows the separate determination of the influence of this changed process parameter in the characterization of the electrochemical processes, and in particular the determination of the impedance of a component caused by this process parameter.

[0031] In one embodiment of the invention, the electroanalytical measuring device is designed to characterize the electrochemical processes by applying a direct or alternating voltage and measuring a resulting direct or alternating current, or by applying a direct or alternating current and measuring a resulting direct or alternating voltage to each of the electrochemical reactor units, and / or the electroanalytical measuring device is designed to determine resistances, capacitances, inductances, and / or impedances of components of each of the plurality of electrochemical reactor units. In particular, voltammetry and / or electrochemical impedance spectroscopy can be performed.

[0032] In one embodiment of the invention, the electroanalytical measuring device comprises one or more potentiostats, preferably with a potentiodynamic measuring unit and / or impedance measuring unit.

[0033] The device thus comprises electrochemical reactor units, each of the reactor units comprising electrodes that can be connected to one or more potentiometers. The design of the electrode connections and the number of potentiometers used can be adapted to the structure of the device and the design of the potentiometer, with one or more multi-channel potentiometers preferably being used. The potentiometers are preferably designed to provide a voltage of up to plus / minus ten volts (+ / - 10 V) and a current of up to at least 0.4 amperes (0.4 A) per channel, with a voltage of + / - 10 V and a current of 2 A per channel being preferred, a voltage of + / - 10 V and a current of 10 A being particularly preferred, and a voltage of + / - 10 V and a current of 20 A being even more preferred.

[0034] In a preferred embodiment of the device, the potentiometer comprises an impedance measuring device, or the potentiometer is designed as such. Using the impedance measuring device, an electrochemical impedance spectroscopic measurement is carried out on individually selected cell types of the reaction units installed in the device under given process parameters. A sinusoidal alternating current voltage with a predetermined amplitude in the range of 2 to 10 mV can be applied to the electrodes. The frequency-dependent alternating current response of the cell system is measured and recorded. During excitation, a frequency range of 1 mHz to 1 MHz is preferably scanned. Preferably, a low-amplitude sinusoidal alternating voltage can be modulated onto a direct voltage to measure the alternating current response of the cell system, with the direct voltage being applied to the cell system to carry out the electrochemical process.For example, one of the reactor units of the reaction device can be regarded as a cell system.

[0035] In one embodiment of the invention, the electroanalytical measuring device is designed to perform a potentiostatic, potentiodynamic and / or more complex alternating current technique on each of the plurality of electrochemical reactor units.

[0036] In one embodiment of the invention, the electroanalytical measuring device is designed to perform the potentiostatic, potentiodynamic and / or more complex alternating current technology on each of the plurality of electrochemical reactor units simultaneously or sequentially.

[0037] The electrochemical plate reactors can be part of process channels, with identical or different processes being carried out in the individual process channels. The electrochemical processes can be carried out in continuous process operation or, alternatively, interrupted by phases of analytical operation. The continuous voltage supply to the electrodes of the reactor unit can also be interrupted, allowing the flow of electrolyte in the reactor unit to be stopped during analytical operation in the form of impedance spectroscopic measurements.

[0038] During analysis operation, where continuous process operation is interrupted, a characterization data set is preferably acquired to characterize the cell components in combination with the selected operating parameters.

[0039] The time period for continuous process operation is preferably in the range of one hour to 180 days, and the time period for performing the analysis operation is preferably in the range of 10 to 180 seconds.

[0040] In one embodiment of the invention, the electroanalytical measuring device comprises a multiplexer, and the multiplexer is designed to connect the electroanalytical measuring device to one of the plurality of electrochemical reactor units of the reaction device in a temporally alternating manner in order to sequentially investigate the electrochemical processes occurring in the plurality of electrochemical reactor units.

[0041] Thus, the electroanalytical measuring device can advantageously be equipped with only one measuring unit, which can perform an electroanalytical measurement on each of the reactor units in alternation. In one embodiment of the invention, the electroanalytical measuring device is designed to characterize the electrochemical processes in each of the electrochemical reactor units in a 2-, 3-, or 4-electrode configuration. Thus, the measuring device can be connected to the reactor unit via a variable number of electrodes, depending on the measurement to be performed.

[0042] In one embodiment of the invention, the device further comprises a control unit designed to control the respective electrochemical reaction in each of the plurality of electrochemical reactor units and / or designed to control the analysis of the electrochemical processes carried out by the electroanalytical measuring device. The control unit can comprise a central control computer connected to a database, as well as control cabinets with control electronics. To control the electrochemical reaction, for example, temperature or pressure can be changed, reactants can be added, or voltages or currents can be applied to the reactor units. The recording of measured values ​​from the electroanalytical measuring device and an analysis unit can also be controlled by the control unit.

[0043] In one embodiment of the invention, the device further comprises one or more analysis units which are designed to analyze reaction products, in particular liquid reaction products, produced in the respective electrochemical reaction in each of the plurality of electrochemical reactor units and, based thereon, to investigate electrochemical processes occurring in the plurality of electrochemical reactor units when carrying out the respective electrochemical reaction.

[0044] In one embodiment of the invention, the control unit is connected to a database, and the control unit is designed to store results of the investigation of the electrochemical processes obtained by the electroanalytical measuring device and / or the analysis unit in the database, and the control unit and / or the database are configured to carry out a data evaluation of the results obtained by the electroanalytical measuring device and / or the analysis unit, and to use a result of the data evaluation to change at least one process parameter in at least one of the plurality of electrochemical reactor units.

[0045] The device is preferably designed to carry out an evaluation process for the acquired measurement data, so that the measurement process also comprises an evaluation process for the measurement data. A measured cell data set can be compared or correlated with data from a database. The data stored in the database can include equivalent circuit diagrams as well as the mathematical formulas that describe the equivalent circuit diagrams. When comparing or correlating the data, those equivalent circuit diagrams are preferably determined that show a high degree of agreement with the measurement data under the given set of process parameters. The result obtained during the evaluation is stored in the database. Preferably, the resistance of the cells or of individual elements of the cells is recorded as a function of the process time and the process parameters and registered in the database.Of particular importance is the differentiation of the total resistance of the cell into its individual resistances of individual elements of the cells in order to test them specifically and, on the basis of the adjustment of process parameters, to adjust them so that these individual resistances have the lowest possible value.

[0046] The device and method according to the invention are preferably combined with an AI system. For example, the artificial intelligence of the AI ​​system can be based on the use of a neural network (NN). The AI ​​system offers the possibility of both analyzing large parameter spaces and processing a large amount of data, whereby the data can originate from many different data sources. In a preferred embodiment, the implementation of the method according to the invention comprises the combination with an AI system, whereby a large amount of data is generated simultaneously and stored in a database.

[0047] In one embodiment of the invention, each of the plurality of electrochemical reactor units is constructed according to a modular system. Preferably, not only the reactor units are constructed according to a modular system, but also the entire device according to the invention, so that the method can be carried out in a flexible manner. A modular device design is characterized in that the device can comprise a reactor module, a gas and analysis module, a liquid supply module, a control cabinet with control electronics, and a central control computer with a database.

[0048] In one embodiment of the invention, the device comprises a temperature control unit designed to control a temperature in each of the plurality of electrochemical reactor units. For example, a heatable furnace in which the plurality of reactor units are arranged can serve as the temperature control unit.

[0049] According to a further aspect of the invention, a method for investigating electrochemical processes in a plurality of electrochemical reactor units using a device according to one of the preceding embodiments is proposed. The method comprises the step of providing a device for investigating electrochemical processes in a plurality of electrochemical reactor units according to one of the preceding embodiments, the step of carrying out a respective electrochemical reaction in each of the plurality of electrochemical reactor units, and the step of investigating the electrochemical processes while carrying out the respective electrochemical reaction in each of the plurality of electrochemical reactor units.

[0050] One goal in implementing the method according to the invention is to generate the broadest possible data set that can be stored in a database in a retrievable form. Preferably, the data set allows for drawing conclusions about production data or making a prediction about production data. The predictions or conclusions about production data make it possible to detect disruptive influences even during the implementation of the method according to the invention. Production data can be data collected from a large-scale plant.

[0051] One result of the method according to the invention is thus the generation of training data, which enables the support of production processes. Preferably, component life cycles can be determined using process parameters that can cause accelerated aging.

[0052] Preferably, the databases generated by the method according to the invention are linked to the production processes, or the process parameters for the production processes can be predicted for the production processes using the method according to the invention. Based on the results of the method according to the invention, disruptions or limitations in future operation can be avoided or minimized, since these can be predicted in advance using training data in a parallel test environment. For example, disruptions or limitations can be caused by the following: too low conversion of valuable product, excessive electrical resistances and thus excessive power consumption, or excessive mass transfer resistances in the cells.

[0053] In one embodiment of the invention, a direct and / or alternating voltage is applied to the electrodes of the electrochemical reactor units. This allows, for example, voltammetry or electrochemical impedance spectroscopy to be performed.

[0054] In one embodiment of the invention, investigating the electrochemical processes comprises measuring cell voltages, potentials and / or currents and / or determining resistances, capacitances, inductances and / or impedances of components of each of the plurality of electrochemical reactor units.

[0055] In one embodiment of the invention, the electrochemical processes are examined during the execution or in temporal alternation with the execution of the respective electrochemical reaction, and / or the step of examining the electrochemical processes is carried out repeatedly when carrying out the respective electrochemical reaction.

[0056] In a preferred embodiment, the method according to the invention comprises carrying out an electrochemical process in a device with two or more, preferably four or more, electrochemical plate reactors arranged in parallel. The electrochemical plate reactors represent part of process channels, with identical or different processes being carried out in the individual process channels. The process can be carried out in a continuous process mode or, alternatively, can include interruptions of the process mode for an analytical operation.

[0057] In one embodiment of the invention, the method further comprises the step of characterizing the electrochemical processes in the plurality of reactor units, wherein during the characterization, measured values ​​of the respective reactor unit are compared with measured values ​​of the reactor unit composed of the components with known impedances, and / or the step of carrying out an electroanalytical calibration measurement (e.g. open circuit) and / or an electrochemical conditioning in each of the plurality of electrochemical reactor units simultaneously or with a time delay.

[0058] In one embodiment of the invention, the step of investigating the electrochemical processes comprises performing potentiostatic, potentiodynamic and / or complex alternating current techniques.

[0059] In one embodiment of the invention, the step of examining the electrochemical processes comprises an electrochemical analysis, preferably carrying out an electrochemical impedance spectroscopy, and further comparing a result of the electrochemical analysis with a plurality of simulated and / or calculated results of a plurality of candidate equivalent circuits for the respective electrochemical reactor unit, and determining that equivalent circuit of the plurality of candidate equivalent circuits which has the greatest agreement in the comparison of the results.

[0060] In one embodiment of the invention, the method further comprises determining resistances, capacitances, inductances and / or impedances of components of each of the plurality of electrochemical reactor units based on the result of the investigation of the electrochemical processes.

[0061] In one embodiment of the invention, the method further comprises the step of adapting a configuration of at least one of the plurality of electrochemical reactor units based on a result of the investigation of the electrochemical processes, and / or the step of adapting at least one process parameter of the respective electrochemical reaction in at least one of the plurality of electrochemical reactor units based on a result of the investigation of the electrochemical processes.

[0062] In one embodiment of the invention, an analytical equation and / or trained artificial intelligence is used for the step of adapting a configuration of at least one of the plurality of electrochemical reactor units and / or for the step of adapting at least one process parameter of the respective electrochemical reaction in at least one of the plurality of electrochemical reactor units. The method according to the invention is preferably carried out in several method stages, wherein it is further preferred that the method comprises the generation of a training data set. Furthermore, it is preferred that the method is combined with a K1 system, wherein the K1 system is used to create or train neural networks.

[0063] A defined experimental setup with process setpoints, cell structure of the reactor units, material composition, etc., can serve as input for a neural network. The measured properties of the experimental setup, such as actual process values, electrochemical measurements, etc., are the output variables or output vector on which the neural network or its matrix is ​​trained to predict the output variables of future experimental setups.

[0064] In one embodiment of the invention, the method further comprises the step of comparing results of the investigation of the electrochemical processes in the plurality of electrochemical reactor units for the purpose of determining an accuracy and / or precision of the measurement results based on the comparison of identically constructed and operated electrochemical reactor units.

[0065] In one embodiment of the invention, the method further comprises the step of storing results of the investigation of the electrochemical processes in a database and performing a data evaluation of the stored results, and the step of using a result of the data evaluation to change at least one process parameter in at least one of the plurality of electrochemical reactor units.

[0066] In one embodiment of the invention, the result of the data evaluation is used to optimize a synthesis procedure for electrochemically active components or parts in the plurality of reactor units.

[0067] Thus, a device and method for conducting electrolysis processes in parallel in one or more electrochemical reactors are provided, wherein the device comprises online analytical devices, a program controller, and a database. The device comprises a plurality of control, regulation, and sensor elements with which process parameters can be set, regulated, and monitored. The process data and sensor data are collected by the program controller during the process and recorded in the database.

[0068] The method according to the invention advantageously makes it possible to carry out a targeted optimization of individual components, namely in the so-called screening operation, in which individual components are specifically examined.

[0069] If the method according to the invention relates to electrochemical cells, one of the relevant parameters is the resistance of a gas diffusion electrode. The method according to the invention makes it possible to use measured values ​​to simply calculate the resistance of the gas diffusion electrodes (GDE) and to plot them graphically using a graphical user interface, advantageously for a large number of measurements taking place simultaneously. It is advantageous that, thanks to the data acquisition and the user interface, the method according to the invention enables an overview of a large number of measured data sets, which are preferably linked to a database in integrated program and evaluation software. Advantages of the method also include the simple graphical representation of measured data, for example, resistance values.The advantage is that this provides an overview of a large number of measurements, thus avoiding complex analytical calculations.

[0070] By pre-training on a standardized kit, the method according to the invention advantageously reduces the number of possible experimental settings that must be tested until a new material or a new structure for carrying out the electrochemical reaction is found.

[0071] A further advantage of the method according to the invention is in particular that improved reproducibility can be achieved through parallel operation or higher data quality, since the elements arranged in parallel can preferably be coupled to analytical devices in online operation and the analyses can be carried out in a narrow time window.

[0072] Thus, the benefits offered by one of the above-mentioned aspects apply equally to all other aspects and vice versa.

[0073] Essentially, the invention relates to a device for investigating electrochemical processes in a plurality of electrochemical reactor units. The device comprises a reaction device with a plurality of electrochemical reactor units, a fluid supply unit, and an electroanalytical measuring device. Each of the electrochemical reactor units of the reaction device is configured to carry out a respective electrochemical reaction, and each of the electrochemical reactor units comprises a plurality of electrodes configured to be connected to the electroanalytical measuring device.The fluid supply unit is designed to supply each of the plurality of electrochemical reactor units with fluids for carrying out the electrochemical reaction, and the electroanalytical measuring device is designed to examine electrochemical processes occurring in the plurality of electrochemical reactor units during the implementation of the respective electrochemical reaction. At least one of the electrochemical reactor units has a plurality of components, wherein the reactor unit is composed of the plurality of components, and wherein an impedance of each of the plurality of components is known. The device is designed to characterize the electrochemical processes in the plurality of reactor units. During the characterization, measured values ​​of the respective reactor unit are compared with measured values ​​of the reactor unit composed of components with known impedances.

[0074] Further features, advantages and possible applications of the invention will become apparent from the following description of advantageous embodiments and the accompanying figures.

[0075] The figures are schematic and not to scale. Where identical reference symbols are used in the following description of the figures, they indicate identical or similar elements.

[0076] Short description of the characters

[0077] Figure 1 shows a schematic representation of a device according to the invention with a modular structure.

[0078] Figure 2a shows a representation of different components that can be used to assemble a modular electrochemical plate reactor.

[0079] Figure 2b shows a schematic representation of different plate reactors formed from the components of Figure 2a, forming different cell types A - E, which can be used for different electrochemical processes.

[0080] Figure 2c shows a representation of the plate reactors shown in Figure 2b, with the electrical connections to the electrodes indicated.

[0081] Figure 3 shows a schematic representation of different reactor units or plate reactors enclosed by housing elements, showing the connection ports to the supply lines and to the discharge lines, which are designed so that the different types of reactors can be easily connected to the fluid supply and the fluid discharge.

[0082] Figure 4a shows a quadruple reactor as reaction device, ie a stacked plate reactor of type A as shown in Figure 3, which is equipped with four identical reactor units.

[0083] Figure 4b shows a quadruple reactor as a reaction device with stacked plate reactors of type C as shown in Figure 3, which is equipped with four identical reactor units.

[0084] Figure 5 shows a group of four electrochemical reactor units as a reaction device, depicting two different plate reactors, namely Type B and Type C, and two electrochemical tubular reactors. Figure 6 shows a schematic section of a device according to the invention equipped with four electrochemical plate reactors, the reactors being arranged in a forced-air furnace.

[0085] Figure 7 shows a representation of a measurement result of a cyclic voltammetry carried out on a reactor unit.

[0086] Figure 8 shows a representation of operating states of a reactor unit, represented in a current / voltage diagram in 4-quadrant operation.

[0087] Figure 9 shows a schematic representation of various equivalent circuits that can be assumed for a reactor cell.

[0088] Figure 10 shows a schematic representation of the method according to the invention for carrying out chemical processes, in which the program control enables feedback for re-executing the method under a changed set of parameters and the database is linked to a Kl system.

[0089] Figure 11 shows a representation of a Nyquist diagram of the frequency-dependent complex impedance of the reactor unit associated with an equivalent circuit.

[0090] The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are provided with the same reference numerals throughout.

[0091] Detailed from

[0092] Figure 1 shows a schematic representation of a device 100 according to the invention with a modular structure, wherein the modules comprise a reaction device 110, an analysis unit 160, a fluid supply unit 130, an electroanalytical measuring device 140 with control cabinet and control electronics, and a control unit 150 with a central control computer and a database.

[0093] Figure 2a shows a representation of various components 121 that can be used to assemble a modular electrochemical plate reactor. This results in a standardized cell kit.

[0094] As components 121 of the reactor unit 120, for example, the housing 121a of a half-cell, the electrolyte channel 121b, electrodes such as anode / cathode 121c, the membrane / diaphragm 121d, the gas diffusion electrode GDE 121e, or the gas channel 121f are used.

[0095] To reduce test times, the electrochemical properties of the cells should be known as extensively as possible before the start of the test. To achieve this, it is advisable to standardize the cells and specify as few components as possible that make up a cell. Therefore, standardized cells should be used, whereby the cells can be assembled from predefined components.

[0096] Components can be considered mechanical components that can be combined to create different cell configurations. Components are electrochemical components to which electrochemical properties such as resistance can be assigned. Components can be parts of components or be identical to components.

[0097] Each component in the kit can be correlated with an impedance, for example, possessing ohmic resistances and capacitive resistances, which can then be differentiated using electrochemical impedance spectroscopy (EIS). Components are defined, if possible, so that they ideally exhibit only one type of resistance, in order to simplify modeling in the equivalent circuit. For example, a Nafion membrane is only an ionic conductor and not catalytically active. Its individual resistance can be measured separately. On the other hand, a flow field has only an ionic resistance and can be measured separately. Components that exhibit more than one resistance can, in simple cases, still be resolved using frequency analysis such as EIS. For example, interfaces are components with a combined resistance.Electrodes or electrolyte interfaces, for example, have a capacitive and an ohmic resistance, which can be separated by applying different frequencies into the capacitive (zero resistance at high frequencies) and the ohmic resistance (independent of the frequency). As a counterexample, the gas diffusion electrode (GDE) is both an electron conductor and an ion conductor with capacitive properties, and a gas and liquid transporter with additional catalytic properties. Their individual resistances can no longer be separated analytically. Components can be identical to physical components. For example, the Flowfield component in the kit is identical to the Flowfield component, which only has an ionic resistance. Components can also be one of several elements of a component. For example, the MEA component in the kit is composed of the membrane components (e.g.Nation), which has ionic resistance and the components catalytic layer or catalytic layer as well as the components electrode / electrolyte transition layer.

[0098] The components of the cell kit can be divided into: i. Chemically (catalytically) active components: o Flat porous components with active centers: GDE, CCM, MEA o Flat non-porous components such as sputtered active surfaces: frequently used in primary screening ii. Physically (potentiostatically active) components: o Electrolyte membrane: ohmic ion resistance and capacitive resistance (e.g. Nafion membrane) iii. Fluid dynamic components: o Electrolyte in the zero-gap flow field (cage): ion passage through diffusion and convective liquid movement o Gas diffusion chamber in front of the GDE: convection and diffusion of gases o Functionalized membrane between two flow fields: only ion passage through ion diffusion (e.g. H+ in PEM, OH- in AEM) (PROTON EXCHANGE MEMBRANE AND ANION EXCHANGE MEMBRANE) o Diaphragm: liquid and ions can diffuse.

[0099] Resistances can also be classified according to spatial allocation and / or spatially differentiable resistances. A modular system for electrochemistry is ideally designed so that the resistances of its components can be spatially allocated. This means that the electrolyte resistance is localized as much as possible to the component that is also responsible for transporting the electrolyte and is therefore used for this task. Therefore, according to this definition, the installation space of the flow field ends exactly where other components or components such as a membrane, electrode, or a GDE are connected. With this spatial delimitation, the so-called IR drop of the electrolyte, for example, only depends on the relevant dimension of the flow field in the direction of the electric field and can be determined prior to the experiment during the modular system calibration.

[0100] In addition, a distinction can be made based on the temporal behavior of resistances. These can be resistances that develop over the course of the experiment, such as the formation of a double layer of charged particles. Such resistances can be determined by comparing the initial and (usually asymptotic) final states.

[0101] More relevant in practice, however, are resistors that depend on temporally varying excitations. Such excitations are applied to the cell's supply voltage as low-amplitude harmonics. Combined components can thus be broken down into their individual components (resistors). The combined double-layer component can be geometrically assigned to an electrode / electrolyte boundary layer and loses its capacitor properties defined by the double-layer capacitance at high frequencies (w -> oo); ZDS = -j / wC. Only the charge transfer resistance remains: ZLÜ = R. Thus, depending on the frequency setting, ZDS and ZLÜ can be determined independently of each other.

[0102] Measurement of individual components (e.g. interfaces) of the cell kit: Each interface can be represented by a Randles equivalent circuit RES. This maps the parallel capacitive and ohmic resistances of the interface as well as the series ohmic electrolyte resistance. A half-cell usually has several interfaces. It is useful to be able to install a reference electrode RE close to each of these interfaces. This allows the equivalent circuits to be measured separately between the RE attached there and the working electrode AE. A half-cell with a flow field between the Nafion membrane and the cathode then consists primarily of the RES for the Nafion membrane and the RES for the electrode and the electrolyte resistance in series. The electrolyte resistance is calculated from the width of the flow field and the proportionally determined resistance from one of the RES.

[0103] Figure 2b shows a schematic representation of different reactor units 120 or plate reactors formed from the components 121 of Figure 2a, which form different cell types that can be used for different electrochemical processes.

[0104] Figure 2c shows a representation of the reactor units 120 or plate reactors shown in Figure 2b, with the electrical connections to the electrodes indicated.

[0105] Figure 3 shows a schematic representation of different plate reactors as reactor units 120, which are enclosed by housing elements, wherein the connection connections to the supply lines and to the discharge lines are shown, which are designed so that the different types of reactors can be easily connected to the fluid supply and the fluid discharge.

[0106] Figure 4a shows a quadruple reactor as reaction device 110, ie a stacked plate reactor of type A as shown in Figure 3, which is equipped with four identical reactor units 120.

[0107] Figure 4b shows a quadruple reactor as reaction device 110 with stacked plate reactors of type C as shown in Figure 3, which is equipped with four identical reactor units 120.

[0108] Figure 5 shows a group of four electrochemical reactor units 120 as reaction device 110, wherein two different plate reactors, namely type B and type C, and two electrochemical tubular reactors are shown.

[0109] Figure 6 shows a schematic section of a device 100 according to the invention, which is equipped with four electrochemical plate reactors as reactor units 120 of the reaction device 110. The reactor units are arranged in a forced-air oven as a temperature control unit 170. An electroanalytical measuring device 140 with a potentiostat 145 is connected to the reactor units 120, and a fluid supply unit 130 supplies the reactor units with fluids such as electrolytes. An analysis unit 160 examines and analyzes the fluids withdrawn from the reactor units 120, and a control unit 150 controls and monitors these systems.A key feature of the test facilities used here is the infrastructure common to all test cells, which ensures that all cells are supplied with media evenly and thus deviations at least affect all cells equally, as well as the analytics common to all cells, which ensures that measurement errors at least affect all cells equally and thus the comparability of the measurements. Against this background, simplified models such as the graphical evaluation proposed here are sufficient to nevertheless assess differences between the cells well. Figure 7 shows a representation of a measurement result from cyclic voltammetry carried out on a reactor unit 120. With the online connection of measuring devices to the workflow in which processes are carried out in electrochemical cells, measurement data can be displayed graphically on a user interface.

[0110] Electrochemical measurement technology:

[0111] • Electrochemical impedance spectroscopy EIS for the determination of material properties: o Stationary potentiostatic or galvanostatic methods are not able to

[0112] Cell resistance is broken down into individual internal resistances. However, to minimize the total voltage of a cell, which is essential for energy consumption, knowledge of the individual resistances is crucial for targeted optimization. Resistors react differently to non-stationary excitation. Capacitors are good conductors at high frequencies but not at low frequencies. Ohmic resistances are frequency-independent. EIS utilizes these properties to differentiate between resistors.

[0113] • Cyclic voltammetry for the characterization of electrodes: o Cyclic voltammetry allows surface reactions (e.g., the adsorption or desorption of protons) at a specific electrode (e.g., a platinum electrode) to be assigned to a specific potential. o If, for example, the same voltammograms are still measured after several cycles, statements can be made about the stability of the electrodes. o This method typically runs through all four quadrants of the voltammogram shown in Figure 7.

[0114] Measurement technology:

[0115] • The electrical engineering basis for determining the product conversions and individual resistances with a given cell configuration are potentiostats and electrochemical impedance spectrometers, which are ideally designed as multi-channel devices.

[0116] • The key component of the device is a modular system for the electrochemical cell, consisting of standardized components that can be combined in a wide variety of ways to create defined cell configurations. The modular system consists of a limited number of components that can be combined to create a variety of cell configurations.

[0117] • The measurement basis is the 4-quadrant operation of the well-known boosters with which source and sink states can be set and high-frequency overshoots which are used to differentiate individual resistances in the cells.

[0118] • In test mode, this simulates, for example, electrolysis processes (power source) or fuel cell operation (power sink), which can be assigned to one of the quadrants. • There are no devices on the market that fully cover this area.

[0119] • The available boosters allow high frequency operation, but have limitations regarding the current and voltage supply.

[0120] • However, you can set operating states that can be represented in a current / voltage diagram, the so-called 4-quadrant operation, as shown in Figure 8 and shows the operating states of a reactor unit 120.

[0121] • Power sources (current and voltage sources with higher power) are also available, but cannot reproduce the high-frequency operation required to determine the individual resistances (use for high surface loads in secondary screening or for larger areas or stack operation in ternary screening).

[0122] • However, a combination of both devices is possible, with the devices being assigned to different power and frequency ranges: o The power source provides a constant supply (DC or voltage) in 2 of the 4 quadrants without superimposed overshoot (f< <1 Hz) o The boosters provide a constant supply in all 4 quadrants with a superimposed harmonic (0< <f< <kHz).

[0123] • This means that the two areas of conversion determination and resistance determination are represented with different devices, but the data is brought together again using a common evaluation software, which both combines the frequency ranges (shown e.g. in the Nyquist diagram) and carries out the correct quadrant assignment in the voltammogram for the evaluation.

[0124] Figure 9 shows a schematic representation of various equivalent circuits 180 that can be assumed for a reactor unit 120. From this possible selection of equivalent circuits ESB, the actual or most suitable ESB is to be selected. An analytical solution for a still relatively simple ESB, after inserting the complex terms for capacitances and ohmic resistances into the mixed series and parallel circuit of the cell model, results in complicated expressions that are not suitable for a rapid assessment of the resistance of a reactor unit such as a gas diffusion cell. Therefore, the solution proposed here is the graphical evaluation of the individual resistances using a pre-trained Kl based on a well-known model kit for electrochemical cells.

[0125] Figure 10 shows a schematic representation of the method according to the invention for carrying out chemical processes, in which the program control enables feedback for re-executing the method under a changed set of parameters and the database is linked to a Kl system.

[0126] The process is explained using the example of the optimization of a gas diffusion electrode GDE:

[0127] A) Modular kit calibration: The modular kit calibration should be performed once before the start of the test, but not before each test. A new calibration is only necessary when newly developed components are added to the kit.

[0128] Carrying out the calibration:

[0129] 1. Installation of inert materials instead of the active materials (example: carbon fleece without Ir catalyst) to avoid additive effects (catalytic potential reduction by active centers).

[0130] 2. Installation of standard materials for the electrodes (nickel foil) or membranes (Nation, Sustainion).

[0131] 3. Combinatorics of the components: all reasonable combinations (for example 13 possible) are measured spectroscopically.

[0132] 4. Determine the individual resistances using EIS and assign the resistances to the components in the database.

[0133] B1) Experiment preparation (training of electrical operating conditions):

[0134] Equivalent circuits depend on the operating state of the potentiostat. They represent not only the internal resistances of a cell type, but also contact resistances or capacitive resistances at the interfaces, which depend on the charge carriers and can vary depending on the direction of ion or electron flow. This knowledge is intended to be conveyed to the neural network here.

[0135] 1. The gas diffusion electrode GDE to be optimized is installed with the same material composition in all channels or reactor units 120 of the device.

[0136] 2. The same cell configuration is installed in each channel.

[0137] 3. Training data sets (equivalent circuits) are generated: Information from the possible 4-quadrant operation of the boosters from source (electrolysis) or load operation (fuel cells) and also from non-typical operation modes (reversed source or load operation) is collected in parallel with 4-fold reproduction (4 channels are each the same), example: Assumption 16 channels: 4 channels in source operation / 4 channels in load operation / 4 channels in reversed source operation / 4 channels in reversed load operation.

[0138] B2) Experiment preparation (process engineering operating conditions) Equivalent circuits can depend on process engineering parameters. The quality of the equivalent circuits should remain unchanged, but the individual resistances can assume different values ​​(ohmic resistances are temperature-dependent). Process engineering knowledge is trained here.

[0139] 1. The GDE to be optimized is installed with the same material composition in all channels.

[0140] 2. The same cell configuration is used in each channel. 3. The training data set is generated by a reasonable variation of T, p, and V with a few sampling points.

[0141] C) Experimental procedure:

[0142] Selection of the appropriate cell configuration from the modular system. Selection of the appropriate process parameters, selection of the appropriate quadrant.

[0143] 1. The test configuration of the cell is, for example, installed 16 times with different materials (of the component = component GDE) and the operating mode in the desired quadrant (e.g. source operation = electrolysis) is set.

[0144] 2. Since it can always be assumed that even identical cells will have slight differences in their resistance, an open-circuit measurement (open-circuit voltage) is performed first. For this purpose, a measuring device is connected that has a higher internal resistance than the resistance of the cell itself. This so-called

[0145] Open circuit voltage is characteristic for each individual cell and is assigned to it for later evaluation.

[0146] 3. Afterwards, the test is switched to a closed-circuit (power voltage) measurement for the long-term test.

[0147] 4. The measured voltammograms are graphically visualized as an array. This provides information about the efficiency of the GDE.

[0148] 5. The measured EIS spectra are converted into equivalent circuits for each material. This provides information about the magnitude of the individual resistors, as the neural network has learned to assign individual resistors to a component based on the diverse training data set created during the experiment preparation.

[0149] 6. This then leads to suggestions for new materials. For example, the ionic conductivity of the Nafion membrane component is a purely ohmic resistance, and this can be reduced by, for example, a higher fluorine content or a smaller thickness.

[0150] 7. Load the cells with the new materials and continue with step 1.

[0151] Figure 11 shows a representation of a Nyquist diagram of the frequency-dependent complex impedance of the reactor unit 120 associated with an equivalent circuit 180.

[0152] In order for a neural network NN to be able to determine individual resistances from measurements, some prerequisites should be met.

[0153] • Setting up equivalent circuit diagrams ESB from individual resistors for the cell.

[0154] • An intelligent algorithm should set up an ESB in such a way that the cell is described physically correctly.

[0155] • As a rule, almost any number of ESBs are able to approximate the measured data well without the approximation having any physical relevance.

[0156] • Therefore, additional restrictions must be found to exclude non-physical ESBs. Possible restrictions:

[0157] • Assignment of known individual resistances to individual components or elements - as far as possible - before the approximation: this is easily possible using the kit from which the cells are put together.

[0158] • Furthermore, individual components or elements can be characterized according to their temporal behavior, which is done by electrochemical impedance spectroscopy EIS.

[0159] • Thirdly, individual resistors can be characterized according to material classes.

[0160] • Fourthly, individual resistors can be characterized according to frequency ranges.

[0161] • An additional restriction, which does not overly restrict the accuracy of the physical representation, may be a limited number of impedance models that the NN may use to create an ESB. For example, most resistors are either:

[0162] • Ohmic: Z_R= + R: Example: Electrode resistance,

[0163] • Inductive: Z_L= + iuoL: Example: Magnetic field around cable,

[0164] • Capacitive: Z_C=-1 / icuC: Example: charge double layer,

[0165] • Constant Phase Element (CPE): Z C PE= - 1 / ( “Qo: Example: non-ideal double layer due to roughness,

[0166] • Gerian element: Z G =- G / (k+icu) 0 - 5 , Example: kinetic reaction coupled with diffusion,

[0167] • Diffusive (Warburg impedance): Z W = - O / CÜ (1— i): Diffusion in the (extended) electrolyte,

[0168] • Diffusive (Warburg impedance): Z W = - O / CÜ (1— i) tanh(5 (irn / D) 0 - 5 ): Diffusion through (thin) boundary layer, or a composition of these resistances.

[0169] Introduction of vector addition:

[0170] In engineering mechanics, mechanical forces acting on components are represented by force vectors. Combined with the inertial forces of the components, these vectors can be used to calculate the motion reactions of the components or even the internal loads within them. These force vectors can be composed of individual vectors and can also be time-dependent.

[0171] Analogous to this procedure, an equivalent circuit can be composed of individual resistors, which in turn can be composed of further individual resistors and can also be time- or frequency-dependent.

[0172] A training algorithm for a neural network based on this system could be based on just a few impedance models for electrical inhibition, including the Warburg impedance for diffusive inhibition and the Gerischer impedance for kinetic response. The vectors are angle-constant, meaning their direction of action does not change with increasing frequency. The purely ohmic resistance is also angle-constant. Its angle is 0° and corresponds to the real axis. The Warburg impedance consists of a real part and an imaginary part, which are proportional to each other, resulting in an angle of 45°. The "direction of action" of the vector is determined by the frequency. The individual inhibitions are represented here as angle-conforming vectors in a Nyquist diagram, as shown in Figure 11 above.

[0173] Individual inhibitions can then easily be added vectorially to a total cell resistance (R as ohmic resistance is a constant, a scalar, so to speak – to stay with the vector model). The figure shows an equivalent circuit for metallic corrosion under a wetted coating as a series circuit consisting of the ohmic resistance of the wetting (electrolyte) Z R and the capacitive resistance of the coating Z c .

[0174] Figure 11 below shows a graphical representation of the frequency-dependent resistance in the complex plane. This representation can be used to determine the equivalent circuit diagram of the reactor unit, including the associated impedance values, either graphically or with a trained artificial intelligence.

[0175] The correct ESB is advantageously selected by ensuring that the endpoints of the resistances obtained by vector addition lie at the measured extreme points if the ESB correctly represents physical reality. Extreme points are the intersection points of semicircles with the x-axis, the vertices of semicircles, the endpoints of ohmic resistances on the x-axis, or the endpoints of capacitive resistances on the x-axis.

[0176] The graphical determination of individual resistances can be performed according to the principle of parsimony, for example, based on a transfer line model (TLM). This model is an approximation of real-life conditions in complex electrical circuits. The Poisson-Nernst-Planck equation describes the real transport of ions through media, and it can be shown that the TLM, for example, results from a simplified solution of the PNP model and approximately describes real transport.

[0177] The model provides less accurate results than the local model, which works with known resistances. However, the model can also be applied when previously unknown (hidden) resistances are present in the test section. In combination with a NN capable of pattern recognition, such hidden resistances can be identified and quantified.

[0178] The method can also be called graphical, since the smallest possible number of functionally identical elements are combined in the TLM to form a 2-phase series circuit and their resistance values ​​are adjusted to the actually measured curve until a desired minimum deviation is present - visible in the desired optical adjustment of the approximation to the real curve shape.

[0179] By keeping the number of elements in the TLM (and other selected models) as small as possible, reality is best represented according to Ockham's principle of parsimony. The TLM assumes that every circuit can be replaced by a two-phase series connection of individual ohmic resistors, with the phases regularly connected by parallel circuits consisting of an ohmic and a capacitive resistor. This equivalent circuit (ESB) is an approximation of overhead lines (large ohmic resistance) on power poles (parallel circuit of an ohmic resistor and a capacitive resistor), as well as the current return via earth (small resistance), as well as the start and end connections, again represented by such a parallel circuit.

[0180] Although the invention has been illustrated and described in detail in the drawings and the foregoing description, these drawings and descriptions are to be considered as illustrative or exemplary in nature and not as restrictive. The invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments may be understood and practiced by those skilled in the art to practice the claimed invention, based on the drawings, the disclosure, and the dependent claims.

[0181] Additionally, it should be noted that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limitations.

[0182]

[0183] Device for investigating electrochemical processes

[0184] Reaction device electrochemical reactor unit

[0185] Components of the reactor unit a Housing of a half-cell b Electrolyte channel c Anode / cathode d Membrane / diaphragm e Gas diffusion electrode GDE f Gas channel

[0186] electrode

[0187] Fluid supply unit electroanalytical measuring device

[0188] Potentiostat

[0189] Control unit

[0190] Analysis unit

[0191] Temperature control unit

[0192] Equivalent circuit diagram

Claims

Claims 1. A device (100) for investigating electrochemical processes in a plurality of electrochemical reactor units (120), the device (100) comprising a reaction device (110) with a plurality of electrochemical reactor units (120); a fluid supply unit (130); and an electroanalytical measuring device (140); wherein each of the electrochemical reactor units (120) of the reaction device (110) is designed to carry out a respective electrochemical reaction; wherein each of the electrochemical reactor units (120) has a plurality of electrodes (125) designed to be connected to the electroanalytical measuring device (140); wherein the fluid supply unit (140) is designed to supply each of the plurality of electrochemical reactor units (120) with fluids for carrying out the electrochemical reaction;and wherein the electroanalytical measuring device (140) is designed to investigate electrochemical processes occurring in the plurality of electrochemical reactor units (120) during the implementation of the respective electrochemical reaction; wherein at least one of the electrochemical reactor units (120) has a plurality of components (121), wherein the reactor unit (120) is composed of the plurality of components (121), and wherein an impedance of each of the plurality of components (121) is known; and wherein the device (100) is designed to carry out a characterization of the electrochemical processes in the plurality of reactor units (120), wherein during the characterization, measured values of the respective reactor unit (120) are compared with measured values of the reactor unit (120) composed of the components (121) with known impedances.

2. The device (100) according to claim 1, wherein the reaction device (110) comprises at least two electrochemical reactor units (120), preferably at least four electrochemical reactor units (120), particularly preferably at least eight electrochemical reactor units (120); and / or wherein each of the electrochemical reactor units (120) of the reaction device (110) has a 2-, 3-, or 4-electrode configuration.

3. The device (100) according to one of claims 1 or 2, wherein the electroanalytical measuring device (140) is designed to carry out an electroanalytical calibration measurement and / or an electrochemical conditioning simultaneously or with a time delay in each of the plurality of electrochemical reactor units (120) before characterizing the electrochemical processes.

4. The device (100) according to any one of the preceding claims, wherein the electroanalytical measuring device (140) is designed to characterize the electrochemical processes by applying a direct or alternating voltage and measuring a resulting direct or alternating current or by applying a direct or alternating current and measuring a resulting direct or alternating voltage to each of the electrochemical reactor units (120), and / or wherein the electroanalytical measuring device (140) is designed to determine resistances, capacitances, inductances and / or impedances of components (121) of each of the plurality of electrochemical reactor units (120).

5. The device (100) according to any one of the preceding claims, wherein the electroanalytical measuring device (140) comprises one or more potentiostats (145), preferably with a potentiodynamic measuring unit and / or impedance measuring unit, and wherein the electroanalytical measuring device (140) is designed to carry out a potentiostatic, potentiodynamic and / or more complex alternating current technique on each of the plurality of electrochemical reactor units (120) simultaneously or sequentially.

6. The device (100) according to any one of the preceding claims, wherein the electroanalytical measuring device (140) comprises a multiplexer, and wherein the multiplexer is designed to connect the electroanalytical measuring device (140) to one of the plurality of electrochemical reactor units (120) of the reaction device (110) in a time-alternating manner in order to sequentially investigate the electrochemical processes occurring in the plurality of electrochemical reactor units (120).

7. The device (100) according to any one of the preceding claims, wherein the electroanalytical measuring device (140) is designed to characterize the electrochemical processes in each of the electrochemical reactor units (140) in a 2-, 3-, or 4-electrode configuration.

8. The device (100) according to any one of the preceding claims, further comprising a control unit (150) configured to control the respective electrochemical reaction in each of the plurality of electrochemical reactor units (120) and / or configured to control the analysis of the electrochemical processes performed by the electroanalytical measuring device (140).

9. The device (100) according to claim 8, wherein the device (100) further comprises one or more analysis units (160) which are designed to analyze reaction products generated during the respective electrochemical reaction in each of the plurality of electrochemical reactor units (120) and, based thereon, to investigate electrochemical processes occurring during the implementation of the respective electrochemical reaction in the plurality of electrochemical reactor units (120).

10. The device (100) according to one of claims 8 or 9, wherein the control unit (150) is connected to a database, and wherein the control unit (150) is designed to store results of the investigation of the electrochemical processes obtained by the electroanalytical measuring device (140) and / or by the analysis unit (160) in the database, and wherein the control unit (150) and / or the database are configured to carry out a data evaluation of the results obtained by the electroanalytical measuring device (140) and / or the analysis unit (160) and to use a result of the data evaluation to change at least one process parameter in at least one of the plurality of electrochemical reactor units (120).

11. The device (100) according to any one of the preceding claims, wherein each of the plurality of electrochemical reactor units (120) is constructed according to a modular system, and / or wherein the device comprises a temperature control unit (170) configured to control a temperature in each of the plurality of electrochemical reactor units (120).

12. A method for investigating electrochemical processes in a plurality of electrochemical reactor units (120) with a device (100) according to one of claims 1 to 11, the method comprising the steps: Providing an apparatus (100) for investigating electrochemical processes in a plurality of electrochemical reactor units (120) according to one of claims 1 to 17; performing a respective electrochemical reaction in each of the plurality of electrochemical reactor units (120); and Investigating the electrochemical processes when carrying out the respective electrochemical reaction in each of the plurality of electrochemical reactor units (120).

13. The method according to claim 12, wherein a direct and / or alternating voltage is applied to the electrodes (125) of the electrochemical reactor units, and wherein the investigation of the electrochemical processes comprises measuring cell voltages, potentials and / or currents and / or determining resistances, capacitances, inductances and / or impedances of components (121) of each of the plurality of electrochemical reactor units (120).

14. The method according to one of claims 12 or 13, wherein the electrochemical processes are examined during the execution of the respective electrochemical reaction or alternately with the execution of the respective electrochemical reaction; and / or wherein the step of examining the electrochemical processes is performed repeatedly during the execution of the respective electrochemical reaction.

15. The method according to any one of claims 12 to 14, further comprising the steps Characterising the electrochemical processes in the plurality of reactor units (120), wherein during the characterisation, measured values of the respective reactor unit (120) are compared with measured values of the reactor unit (120) composed of the components (121) with known impedances; and / or Carrying out an electroanalytical calibration measurement and / or an electrochemical conditioning in each of the plurality of electrochemical reactor units (120) simultaneously or staggered in time, and wherein the step of investigating the electrochemical processes comprises carrying out potentiostatic, potentiodynamic and / or complex alternating current techniques.

16. The method according to any one of claims 12 to 15, wherein the step of examining the electrochemical processes comprises electrochemical analysis, preferably performing electrochemical impedance spectroscopy, and further comprising: Comparing a result of the electrochemical analysis with a plurality of simulated and / or calculated results of a plurality of candidate equivalent circuit diagrams (180) for the respective electrochemical reactor unit (120), and Determining the equivalent circuit diagram (180) of the plurality of candidate equivalent circuit diagrams (180) which has the greatest agreement in the comparison of the results.

17. The method according to any one of claims 12 to 16, further comprising the steps of storing results of the investigation of the electrochemical processes in a database and performing a data analysis of the stored results, and using a result of the data analysis to change at least one process parameter in at least one of the plurality of electrochemical reactor units (120); and wherein preferably the result of the data analysis is used to optimize a synthesis recipe of electrochemically active components (121) in the plurality of reactor units (120).

Images