Multi-reactant catalytic intermediate tracing and kinetic decoupling method

Abstract

The invention discloses a multi-reactant catalytic intermediate tracing and kinetic decoupling method. The method comprises the following steps: building a multi-reactant phase sensitive detection in-situ infrared online test system; designing concentration change modes of different periods for each reactant; after detection is started, the concentrations of all reactants are periodically changed, infrared spectrum data at all sampling time points are collected, and the concentrations of the reactants are calculated; performing time-dependent to phase-dependent conversion on the detection result to obtain a concentration conversion result and an absorbance conversion result of each reactant; determining the characteristic wave numbers of a plurality of candidate intermediates and main reaction products, extracting phase-dependent absorbance from the absorbance conversion results of the reactants according to the characteristic wave numbers, and calculating the maximum intensity of the phase-dependent absorbance and the phase difference between the phase-dependent absorbance and the concentration conversion results of the corresponding reactants to obtain the calculation results of the candidate intermediates and the main reaction products; and analyzing an intermediate source, main and side reaction decoupling and an intermediate generation sequence. The method can make up the key defects in the research of a multi-reactant interface catalytic mechanism.

Description

Technical Field

[0001] This invention belongs to the field of characterization of catalytic reactions and interfacial processes, and specifically relates to a method for tracing and decoupling the kinetics of multi-reactant catalytic intermediates. Background Technology

[0002] Catalytic reactions are widely used in energy conversion and environmental governance systems, serving as a crucial pathway for the resource utilization of greenhouse gases, the efficient removal of organic pollutants, and the green synthesis of various chemicals. Developing efficient and stable catalytic systems and catalysts relies on fundamental research into relevant interfacial processes, with the tracing of reaction intermediates and the elucidation of their kinetic behavior being core components of reaction mechanism research. By revealing the origins, evolution pathways, and coupling relationships between intermediates and reactants, realistic reaction pathway models can be constructed, providing a basis for the rational design of catalysts and the optimization of reaction systems.

[0003] Currently, the detection of intermediates mainly relies on in-situ infrared, in-situ Raman, in-situ X-ray absorption, in-situ X-ray photoelectron spectroscopy, in-situ ultraviolet-visible absorption, and in-situ fluorescence emission spectrometry, combined with difference spectroscopy, isotope labeling, and multivariate statistical methods to identify intermediate signals from complex spectra. Principal component analysis and multivariate curve resolution are then used as chemometric methods to trace reaction intermediates from complex spectral backgrounds. However, due to the low content, short lifetime, poor stability, and high overlap between the spectral signals and reactants and products of interfacial intermediates, existing methods have significant limitations in terms of signal-to-noise ratio, temporal resolution, and signal decoupling.

[0004] Currently, the main technical approaches for tracing and decoupling intermediates in catalytic reactions involving multiple reactants can be summarized into the following three categories: the first category is intermediate tracing and signal decoupling based on in-situ vibrational spectroscopy combined with chemometrics; the second category is intermediate tracing and decoupling analysis methods based on isotope labeling combined with online mass spectrometry / chromatography; and the third category is the method for determining the reaction rate constant of intermediates in electrocatalytic and photoelectrocatalytic systems (CN119595575A) previously proposed by the inventors.

[0005] However, none of the above three methods can simultaneously meet the comprehensive requirements of "accurate tracing of intermediate sources, effective signal decoupling, and determination of generation order" in interfacial catalysis systems involving multiple reactants. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a method for tracing and decoupling the kinetics of multi-reactant catalytic intermediates. The technical problem to be solved by this invention is achieved through the following technical solution: A method for tracing and decoupling the kinetics of multi-reactant catalytic intermediates includes: S1, Build an in-situ infrared online testing system for phase-sensitive detection of multiple reactants; S2, identify multiple reactants and design different concentration change patterns for each reactant over different periods; S3. Based on the system, after completing the background spectral data acquisition, the detection is started, so that the concentration of each reactant changes periodically according to its own concentration change mode. At the same time, infrared spectral data at each sampling time point are collected, including the absorbance corresponding to the wavenumber, and the reactant concentration at each sampling time point is calculated to obtain the detection results after multiple periodic changes. S4, convert the detection results from time-dependent to phase-dependent to obtain the concentration conversion results and absorbance conversion results of each reactant; S5. Determine the characteristic wavenumbers of multiple candidate intermediates and the main product of the reaction. For each characteristic wavenumber, extract the phase-dependent absorbance at that characteristic wavenumber from the absorbance conversion results of each reactant, and calculate its maximum intensity and its phase difference with the corresponding reactant concentration conversion results. Together, they form the calculation results of that characteristic wavenumber, thereby obtaining the calculation results of the candidate intermediates and the main product of the reaction. S6. Based on the calculation results of each candidate intermediate and the main product of the reaction, perform intermediate source analysis, main and side reaction decoupling analysis, and intermediate formation sequence analysis.

[0007] In one embodiment of the present invention, the multi-reactant phase-sensitive detection in-situ infrared online testing system includes: In-situ infrared spectroscopy acquisition unit, reaction unit, control unit, and data acquisition and processing unit; wherein: The in-situ infrared spectroscopy acquisition unit is used to acquire time-resolved infrared spectral data of the reaction interface in real time during the reaction process. The reaction unit is located in the in-situ infrared spectroscopy acquisition unit and is used to contain reactants and form a reaction environment. The control unit is used to control the reactant concentration by controlling the reactant flow rate according to the concentration change pattern of each reactant in different cycles, and to realize inter-system control. The data acquisition and processing unit is used to record time data, spectral data, calculate concentration data, and perform related calculations and analysis.

[0008] In one embodiment of the present invention, in S2, different concentration change patterns are designed for each reactant over different periods, including: Waveform functions with different periods are designed for each reactant to indicate the periodic changes in reactant concentration, wherein the waveform functions include sine waves, square waves, and step waves.

[0009] In one embodiment of the present invention, the control unit includes a flow control system, a function waveform generator, and a trigger controller; wherein, the flow control system includes a flow controller corresponding to each reactant, the function waveform generator is used to generate a pre-designed waveform function for each reactant, and outputs it to the corresponding flow controller in the flow control system, so that the flow controller performs flow control according to the given waveform function to achieve concentration control; the trigger controller is also used to realize the synchronous operation of the in-situ infrared spectroscopy acquisition unit, the flow control system, the function waveform generator, and the data acquisition and processing unit.

[0010] In one embodiment of the present invention, the plurality of reactants includes reactant A and reactant B; In S3, the process of obtaining detection results after multiple periodic changes includes: After the detection is initiated, the concentration of reactant A is periodically adjusted according to its waveform function. The concentration of reactant B undergoes periodic changes, varying periodically according to its waveform function. The system undergoes periodic changes and adjusts the concentration of the inert gas to maintain a steady-state baseline in real time; among which, ; After the detection is started, it is synchronized at a preset sampling interval. Collect data at each sampling time point. The infrared spectral data were recorded, and each sampling time point was recorded. And calculate each sampling time point The concentration of the corresponding reactant A Concentration of reactant B The detection results were obtained after multiple cycles of reactant changes, among which, Less than and ; Each sampling time point The corresponding infrared spectral data is a wavenumber. and absorbance Two-dimensional matrix data.

[0011] In one embodiment of the present invention, S4 includes: Get multiple custom phases ,in, The range of values ​​is ; Based on the corresponding conversion formula, the concentration of reactant A in the detection results is... Concentration of reactant B and absorbance According to each phase Transform them separately to obtain each phase. Under Dependency , , and ; The corresponding conversion formulas include: ; ; ; ; in, This represents the result of the concentration conversion of reactant A; This represents the result of the concentration conversion of reactant B; For The result is the periodic absorbance conversion. For The result is the periodic absorbance conversion. and These are the periods of change in the concentration of reactant A and the periods of change in the concentration of reactant B, respectively. This is the end time of the detection. In one embodiment of the present invention, in S5: The process of obtaining the computational results of candidate intermediates includes: For the feature wavenumber corresponding to each candidate intermediate From Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at and from Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at ; calculate maximum strength ,as well as maximum strength ; calculate Conversion results of reactant A concentration phase difference ,as well as Conversion results of reactant B concentration phase difference To obtain each characteristic wavenumber Data group As the corresponding intermediate The calculation results; The process of obtaining the calculated results for the main product of the reaction includes: For the characteristic wavenumbers corresponding to the main product of the reaction From Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at and from Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at ; calculate maximum strength ,as well as maximum strength ; calculate Conversion results of reactant A concentration phase difference ,as well as Conversion results of reactant B concentration phase difference The characteristic wavenumber is obtained. Data group As the main product of the reaction The calculation results.

[0012] In one embodiment of the present invention, in step S6, based on the calculation results of each candidate intermediate and the main reaction product, an intermediate source analysis is performed, including: For each intermediate In its calculation results, if the maximum strength Greater than maximum strength If the value exceeds at least one order of magnitude, then the intermediate is considered to be... The source of its formation is reactant A; if the maximum intensity Greater than maximum strength If the concentration exceeds at least one order of magnitude, then the intermediate is determined to originate from reactant B; if the maximum intensity... and maximum strength If they are of the same magnitude, then the intermediate is determined to be of that magnitude. The product originates from reactant A and reactant B, thus yielding each intermediate. The source analysis results.

[0013] In one embodiment of the present invention, in step S6, based on the calculation results of each candidate intermediate and the main reaction product, a decoupling analysis of the main and side reactions is performed, including: For the main product of the reaction In its calculation results, if the maximum strength Greater than maximum strength If the intensity exceeds at least one order of magnitude, then the main reaction is determined to favor the pathway dominated by reactant A; if the maximum intensity... Greater than maximum strength If the value exceeds at least one order of magnitude, then the main reaction is determined to be biased towards the path dominated by reactant B, thus obtaining the main reaction biased path result. For each intermediate If the source analysis results are consistent with the main reaction biased pathway results, then the intermediate is preliminarily identified. It is an intermediate in the main reaction pathway; otherwise, it is preliminarily determined that this intermediate is... It is a side reaction pathway intermediate, and this intermediate is obtained. The primary determination result of the reaction pathway source; If the intermediate The source analysis results indicate that the phase difference in the calculation results originates from reactant A. Is it located in If it falls within the specified range, then the intermediate is preliminarily determined to be... It is a main reaction pathway intermediate; if not, this intermediate is preliminarily identified. It is a side reaction pathway intermediate, and this intermediate is obtained. The second determination result regarding the source of the reaction pathway; If the intermediate The source analysis results indicate that the phase difference in the calculation results originates from reactant B. Is it located in If it falls within the specified range, then the intermediate is preliminarily determined to be... It is a main reaction pathway intermediate; if not, this intermediate is preliminarily identified. It is a side reaction pathway intermediate, and this intermediate is obtained. The second determination result regarding the source of the reaction pathway; When the intermediate When the sources determined by the first determination of the reaction channel source and the second determination of the reaction channel source are consistent, the intermediate is obtained. The final determination result of the reaction channel source is obtained, thereby obtaining the final determination result of the reaction channel source of each intermediate, and completing the decoupling analysis of the main and side reactions.

[0014] In one embodiment of the present invention, in step S6, based on the calculation results of each candidate intermediate and the main reaction product, an intermediate generation order analysis is performed, including: If the source analysis result of the intermediate is derived from reactant A, then the phase difference corresponding to reactant A in the calculation results of all intermediates should be considered. The intermediates are sorted in ascending order to characterize the order of formation of intermediates along the relevant channels of reactant A, thereby obtaining the analysis results of the intermediate formation order with reactant A as a reference. If the source analysis result of the intermediate is derived from reactant B, then the phase difference corresponding to reactant B in the calculation results of all intermediates should be considered. The intermediates are sorted in ascending order to characterize the order of formation of intermediates along the relevant pathways of reactant B, thus obtaining the analysis results of the intermediate formation order with reactant B as a reference.

[0015] To address the problems of existing in-situ vibrational spectroscopy, isotope labeling combined with online mass spectrometry / chromatography, and in-situ electrochemical spectroscopy based on phase-sensitive detection in interfacial catalytic systems involving multiple reactants, such as difficulty in determining the source of intermediates, difficulty in effectively decoupling spectral signals, and incomplete acquisition of kinetic information, this invention proposes a method for tracing intermediates and decoupling kinetics in multi-reactant catalytic reaction systems. This method is suitable for intermediate tracing and kinetic studies in multi-reactant interfacial catalytic reaction systems.

[0016] The multi-reactant catalytic intermediate tracing and kinetic decoupling method provided in this invention inherits the advantages of high sensitivity and high signal-to-noise ratio of the previously proposed phase-sensitive detection method. It introduces periodic modulation of multi-reactant concentration and time-phase conversion analysis. This not only continues the advantages of phase-sensitive technology in terms of signal-to-noise ratio and detection sensitivity, but also establishes a direct mapping relationship between "intermediate signal - multi-reactant periodic change" by designing differentiated periodic change characteristics for different reactants. In complex multi-reactant systems, this method achieves accurate tracing of intermediate sources, effective decoupling of main and side reaction intermediates, and quantitative determination of the order of intermediate formation and kinetic characteristics in the main reaction channel. Thus, it solves the key problem of intermediate research in complex multi-reactant interface catalytic systems in existing technologies. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of a multi-reactant catalytic intermediate tracing and kinetic decoupling method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the principle and process of the multi-reactant catalytic intermediate tracing and kinetic decoupling method provided in the embodiments of the present invention; Figure 3 This is an example composition diagram of an in-situ infrared online testing system for multi-reactant phase-sensitive detection in an embodiment of the present invention; Figure 4 This is a diagram showing the composition of the reaction chamber in an embodiment of the present invention; Figure label: 1: Time-resolved Fourier transform infrared spectrometer; 2: In-situ reaction chamber; 3: Flow control system; 4: Function waveform generator; 5: Trigger controller; 6: Includes data acquisition and processing unit; 3-1: Flow controller for reactant A; 3-2: Flow controller for reactant B; 3-3: Flow controller for inert gas C; 201: Main body of reaction chamber; 202: Infrared light transmission window; 203: Sample fixation chamber; 204: Inlet channel; 205: Outlet channel. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0019] Currently, the main technical approaches for tracing and decoupling intermediates in catalytic reactions involving multiple reactants can be summarized into the following three categories: the first category is intermediate tracing and signal decoupling based on in-situ vibrational spectroscopy combined with chemometrics; the second category is intermediate tracing and decoupling analysis methods based on isotope labeling combined with online mass spectrometry / chromatography; and the third category is the method for determining the reaction rate constant of intermediates in electrocatalytic and photoelectrocatalytic systems (CN119595575A) previously proposed by the inventors.

[0020] The first type of intermediate tracing and signal decoupling method based on in-situ vibrational spectroscopy combined with chemometrics is based on the following idea: using vibrational spectroscopy techniques such as in-situ infrared spectroscopy and in-situ Raman spectroscopy, the characteristic vibrational peaks of interfacial species are directly monitored, and intermediate signals are extracted from complex spectra through data analysis methods to achieve intermediate tracing and decoupling analysis.

[0021] However, this type of method has the following limitations: (1) Limited sensitivity for detecting low-concentration, short-lived intermediates: Interfacial intermediates are typically generated in extremely low quantities, have very short lifetimes, and exhibit poor stability. Their signals are easily overwhelmed by strong solvent absorption, carrier background, or signals from other species. Conventional in-situ vibrational spectroscopy, under finite integration time and optical path conditions, yields low signal-to-noise ratios, making reliable analysis of weak-signal intermediates difficult even with differential spectroscopy and baseline correction.

[0022] (2) Severe spectral overlap, signal decoupling depends on strong prior assumptions: In systems with multiple reactants and intermediates operating in parallel, the vibrational characteristic peaks of different species often overlap significantly. While chemometric methods (such as PCA and MCR-ALS) can separate several "virtual components" to some extent, their results are highly dependent on prior information such as initial guesses, constraints, and the number of preset components. Different settings may yield different "separation spectra." This introduces uncertainty into the species attribution of intermediate signals and their correspondence with specific reaction pathways.

[0023] (3) Lack of quantitative resolution of multi-reactant coupling effects: For interfacial processes involving multiple reactants, the above methods are insufficient to distinguish the relative contributions of different reactants to the signal of the same intermediate in a single experiment. Furthermore, they are unable to quantitatively separate information from spectral data regarding "which reactant a certain intermediate comes from and in which channel it is generated," thus limiting a deeper understanding of the coupling mechanism of multiple reactants.

[0024] The second type of intermediate tracing and decoupling analysis method is based on isotope labeling combined with online mass spectrometry / chromatography. By labeling specific reactants with isotopes and combining them with online mass spectrometry or chromatography-mass spectrometry, the composition and isotope distribution of intermediates and products can be analyzed, thereby determining the source of intermediates and characterizing the kinetic process.

[0025] However, this type of method has the following limitations: (1) It relies on intermediates to enter the detection unit, making it difficult to cover pure interfaces and extremely short-lived species: Isotope labeling combined with online mass spectrometry / chromatography typically requires that intermediates or their derivatives enter the gas or liquid phase detection channel in a free or collectable form. For intermediates that exist only at the solid-liquid or solid-gas interface, are difficult to desorb, or have extremely short lifetimes, such methods often cannot directly observe them. Their information can only be indirectly inferred from the isotopic distribution of the final product or stable intermediates, which involves considerable uncertainty.

[0026] (2) The signal is a composite contribution from multiple paths, and the response channels are difficult to completely decouple: The signals provided by online mass spectrometry / chromatography are usually the result of the combined effects of multiple reaction pathways and intermediates. Isotope labeling can distinguish atomic fragments from different sources, but it is difficult to distinguish the superposition of contributions from the same atomic fragments in different reaction channels. It is difficult to accurately separate parallel reaction pathways based solely on changes in mass number or isotope peak shape.

[0027] (3) Lack of information on interface structure and adsorption state makes it difficult to correspond to specific surface sites: This type of method mainly provides information on the composition and isotopic distribution of intermediates or products in the bulk or gas phase. It lacks the ability to directly characterize key information such as the adsorption configuration, coordination environment and electronic structure of intermediates at the interface. Therefore, it is difficult to correspond one-to-one with specific catalytic sites or surface structures, which limits the fine analysis of interface mechanisms.

[0028] The third category, CN119595575A ("A Method for Determining the Rate Constant of Intermediate Reactions in Electrocatalytic and Photocatalytic Systems"), firstly, establishes a phase-sensitive in-situ electrochemical infrared spectroscopy testing system. This system includes a time-resolved infrared spectrometer, an electrochemical workstation, a function waveform generator, a trigger controller, and data acquisition and processing equipment. Secondly, for the applied potential used to power the testing system, a current period indicating its change is set, and corresponding test operations are performed to obtain test data under the periodic drive of the applied potential corresponding to the current period. The set period is then changed to complete test operations for multiple different periods. The test data corresponding to each period includes real-time potential and real-time voltage during the electrocatalytic or photocatalytic reaction. Electrochemical data, including flow and electrochemical testing times, and infrared spectral data consisting of infrared testing times, wavenumbers corresponding to different infrared testing times, and real-time absorbance; the electrochemical data comes from the electrochemical workstation, and the infrared spectral data comes from the time-resolved infrared spectrometer; next, the test data corresponding to each period are classified and processed separately; then, the classified test data for each period are converted from time-dependent to phase-dependent, thereby obtaining the infrared spectra corresponding to different phases in the corresponding period, and solving for the phase difference of the intermediate infrared signal corresponding to the corresponding period; finally, after obtaining the phase difference of the intermediate infrared signal corresponding to different periods, the intermediate reaction rate constant is solved by data fitting. CN119595575A establishes the intermediate signal phase difference Based on the relationship between the applied potential period and the intermediate reaction rate constant, a novel method for determining the intermediate reaction rate constant in electrocatalytic and photoelectrocatalytic systems using phase-sensitive detection in-situ electrochemical infrared spectroscopy (PSD-FTIR) is proposed. This method effectively eliminates interference on the intermediate reaction rate constant caused by factors such as the complexity of electrocatalytic and photoelectrocatalytic reaction systems, high charge transport rates, high environmental noise, and the susceptibility of intermediate signals and kinetics to environmental disturbances, enabling accurate determination of the intermediate reaction rate constant.

[0029] However, this type of method has the following limitations: (1) It only targets potential modulation and cannot explicitly distinguish the contributions of multiple reactants: This in-situ electrochemical spectroscopy scheme applies only periodic modulation to the potential. The response of the intermediate signal to this perturbation is the result of the combined effects of multiple reaction pathways and multiple reactants, ultimately yielding the phase and amplitude of the "total response," which is difficult to decompose into the independent contributions of each reactant.

[0030] (2) It amplifies all intermediate signals that are sensitive to the disturbance simultaneously, but lacks the ability to distinguish the source: The amplified signal extracts the overall spectral component that is in sync with the reference frequency. When multiple intermediates sensitive to potential perturbations exist in the system, the signals of all these intermediates are synchronously amplified and superimposed. Even with multi-frequency or harmonic analysis, the distinction is mainly made based on time scale and degree of nonlinearity, and it is still impossible to directly and clearly map a particular intermediate to the transformation process of a specific reactant or reaction pathway.

[0031] (3) It is difficult to achieve complete decoupling of intermediate signals in multi-reactant systems: In interfacial catalysis involving multiple reactants, the adsorption, activation, and transformation processes of different reactants are highly coupled, and multiple intermediates may share the same or similar vibrational characteristics. The phase response obtained by potential modulation is only a projection of the overall process, and it is difficult to fully decouple the intermediate signals from different reactants and different pathways in the frequency or phase domain, which limits the determination of critical pathways in multi-channel reaction networks.

[0032] (4) Phase information cannot be directly used to deduce the specific source of intermediates and reaction sequence: In existing methods, the phase angle mainly reflects the time lag or lead of the intermediate signal relative to the potential perturbation, and is mostly used to distinguish between "fast processes" and "slow processes" or to determine whether the process is diffusion-controlled. In multi-reactant systems, a single phase angle often integrates the contributions of multiple elementary steps, making it difficult to determine which reactant a particular intermediate originates from or which reaction pathway it is located in based solely on the phase magnitude, and also making it difficult to reliably determine the order of formation among multiple intermediates.

[0033] (5) It is not possible to systematically establish a one-to-one correspondence between "intermediate-multi-reactant periodic changes" in the same test system: Due to the lack of independent modulation dimensions and analytical frameworks designed for different reactants, existing potential-phase sensitive detection methods cannot correlate intermediate signals with the periodic changes of each reactant under the same experimental conditions. In other words, they cannot establish clear mapping relationships such as "intermediate signal – periodic change of reactant A" or "intermediate signal – periodic change of reactant B." This makes it difficult to accurately trace the source of intermediates and quantitatively determine the order of formation of multiple intermediates in systems involving multiple reactants. To overcome the above-mentioned defects, embodiments of the present invention provide a method for tracing and decoupling the catalytic intermediates of multiple reactants, which involves the study of the catalytic reaction mechanism involving multiple reactants, specifically including tracing, decoupling and kinetic analysis of reaction intermediates.

[0034] Please refer to Figure 1 and Figure 2 It is understood that this method for tracing and decoupling the kinetics of multi-reactant catalytic intermediates may include the following steps S1 to S6: S1, Build an in-situ infrared online testing system for phase-sensitive detection of multiple reactants; A multi-reactant phase-sensitive detection in-situ infrared online testing system (hereinafter referred to as the System) is used for in-situ characterization of interfacial catalytic reactions. The System includes: In-situ infrared spectroscopy acquisition unit, reaction unit, control unit, and data acquisition and processing unit; wherein: The in-situ infrared spectroscopy acquisition unit is used to acquire time-resolved infrared spectral data of the reaction interface in real time during the reaction process. The reaction unit is located in the in-situ infrared spectroscopy acquisition unit and is used to contain reactants and form a reaction environment, such as a gas-solid, liquid-solid or gas-liquid-solid interface catalytic reaction environment. The control unit is used to control the reactant concentration by controlling the reactant flow rate according to the concentration change pattern of each reactant in different cycles, and to realize inter-system control. The data acquisition and processing unit is used to record time data, spectral data, calculate concentration data, and perform related calculations and analysis.

[0035] S2, identify multiple reactants and design different concentration change patterns for each reactant over different periods; First, select the target interface catalytic reaction system and determine the multiple reactants participating in the reaction. The multiple reactants include at least reactant A and reactant B, and if necessary, reactant C, etc. The reactants can be in gaseous or liquid state.

[0036] Next, the baseline reaction conditions for each reactant are set to reach the steady-state baseline, such as total flow rate, reaction temperature, pressure, solution composition, and potential (if electrocatalytic / photocatalytic systems are involved), to ensure that the system is in a stable or quasi-steady-state operating range (i.e., steady-state baseline).

[0037] Then, different periodic concentration change modes are designed for each reactant. The purpose is to design different periodic modulation modes for the concentration of multiple reactants to achieve periodic concentration changes.

[0038] The embodiments of the present invention can employ any periodic variation method to design reactant concentration changes. In one optional embodiment, different periodic concentration variation methods are designed for each reactant, including: Waveform functions with different periods are designed for each reactant to indicate the periodic changes in reactant concentration, wherein the waveform functions include sine waves, square waves, and step waves.

[0039] In this embodiment of the invention, the control unit can generate waveform functions of different periods for each reactant to achieve periodic concentration changes. Therefore, under this concentration change mode, the system can specifically adopt the following structure, please refer to [link / reference]. Figure 3 , Figure 3 This is an example structural diagram of an in-situ infrared online testing system for phase-sensitive detection of multiple reactants in an embodiment of the present invention. For ease of understanding, the multiple reactants in this embodiment include reactant A and reactant B as an example. If reactant A and reactant B are gases, an inert gas C is required for dilution during the reaction process. If reactant A and reactant B are liquids, a liquid C, such as an aqueous solution, is required for dilution during the reaction process.

[0040] The in-situ infrared spectroscopy acquisition unit employs a time-resolved Fourier transform infrared spectrometer 1; the reaction unit is specifically an in-situ reaction chamber 2. Figure 3 The control unit includes a flow control system 3, a function waveform generator 4, and a trigger controller 5, as well as a data acquisition and processing unit 6 (see [link to data acquisition and processing unit]). Figure 3 (Data acquisition and processing in the process).

[0041] The following explanation will take the gas-solid interface catalytic reaction involving two gaseous reactants, A and B, as an example.

[0042] The flow control system includes flow controllers for the reactants, such as flow controller 3-1 for reactant A, flow controller 3-2 for reactant B, and flow controller 3-3 for inert gas C. The gas source for reactant A is connected to flow controller 3-1, which controls the flow rate of reactant A to control its concentration in reaction chamber 2. Similarly, the gas source for reactant B is connected to flow controller 3-2, which controls the flow rate of reactant B to control its concentration in reaction chamber 2. Likewise, the gas source for inert gas C is connected to flow controller 3-3, which controls the flow rate of inert gas C to control its concentration in reaction chamber 2. This control ensures a constant total flow rate during the detection process, maintaining a steady-state baseline (e.g., a total flow rate of 100 sccm and atmospheric pressure).

[0043] The function waveform generator is used to generate pre-designed waveform functions for each reactant and output them to the corresponding flow controller in the flow control system, so that the flow controller performs flow control according to the given waveform function to achieve concentration control; the trigger controller is also used to realize the synchronous operation of the in-situ infrared spectroscopy acquisition unit, the flow control system, the function waveform generator and the data acquisition and processing unit.

[0044] The data acquisition and processing unit 6 is used to record the infrared spectral data at each sampling time point. Based on the flow rate output by the flow controller and the total flow rate at the steady-state baseline, it calculates the concentrations of reactant A and reactant B at each sampling time point and performs subsequent analysis and calculations. The calculation of the concentrations of reactant A and reactant B at each sampling time point based on the flow rate output by the flow controller and the total flow rate at the steady-state baseline is a conventional calculation method and will not be detailed here.

[0045] It should be noted that when reactants A and B are in liquid state, the corresponding flow controllers are used to control the liquid flow rate to achieve concentration control and maintain the corresponding steady-state baseline state, which will not be described in detail here.

[0046] Please continue reading Figure 4 , Figure 4 This is a diagram illustrating the composition of the reaction chamber in an embodiment of the present invention. It corresponds to the case where the reactants are in a gaseous state. Specifically: The reaction chamber 2 consists of a reaction chamber body 201, an infrared light transmission window 202, a sample fixation chamber 203, an inlet channel 204, and an outlet channel 205. The sample fixation chamber 203 is located in the middle of the reaction chamber body 201, adjacent to the infrared light transmission window 202, so that the infrared beam forms a transmission detection area at the window-catalyst interface.

[0047] When the reactants are in a liquid state, the structure of the reaction chamber can be designed accordingly, and no restrictions or explanations will be given here.

[0048] S3. Based on the system, after completing the background spectral data acquisition, the detection is started, so that the concentration of each reactant changes periodically according to its own concentration change mode. At the same time, infrared spectral data at each sampling time point are collected, including the absorbance corresponding to the wavenumber, and the reactant concentration at each sampling time point is calculated to obtain the detection results after multiple periodic changes. First, when collecting background spectral data, the reaction chamber body 201 contains only the catalyst and inert gas C.

[0049] Infrared absorbance is measured using the formula A = log(I0 / I), where A is absorbance, I0 is the transmitted light intensity recorded in the background spectrum, and I is the transmitted light intensity recorded in the sample spectrum. Therefore, background testing provides fundamental data for infrared spectroscopy testing, enabling the acquisition of corresponding infrared spectral data in subsequent testing operations. Background spectral data acquisition is performed using a time-resolved Fourier transform infrared spectrometer. For details on the acquisition principle and process, please refer to relevant technical explanations; they will not be elaborated upon here.

[0050] After completing the background spectral data acquisition, the time-resolved Fourier transform infrared spectrometer 1 starts detection and simultaneously sends an electrical signal to the trigger controller 5. The trigger controller 5 triggers the function waveform generator 4, which then controls each flow controller to start working in a periodic waveform mode by setting a periodic waveform. By controlling their output flow rates, the concentrations of reactant A, reactant B, and dilution gas C are adjusted, so that the flow rate of reactant A oscillates around its reference flow rate, and the flow rate of reactant B oscillates around its reference flow rate, achieving periodic changes in concentration. However, the total flow rate is always controlled at 100 sccm, and the pressure is at atmospheric pressure to maintain steady-state reference conditions. The entire triggering process is in the millisecond range, so no feedback signal is sent to the time-resolved Fourier transform infrared spectrometer 1.

[0051] Furthermore, after the detection begins, the data acquisition and processing unit 6 simultaneously records the acquisition time, acquires and records infrared spectral data, calculates the concentrations of reactants A and B, and performs other calculations and analyses.

[0052] Specifically, in S3, the process of obtaining detection results after multiple periodic changes includes: After the detection is initiated, the concentration of reactant A is periodically adjusted according to its waveform function. The concentration of reactant B undergoes periodic changes, varying periodically according to its waveform function. Periodic changes are made, and the concentration of inert gas C is adjusted to maintain a steady-state baseline in real time; among which, ; After the detection is started, it is synchronized at a preset sampling interval. Collect data at each sampling time point. The infrared spectral data were recorded, and each sampling time point was recorded. And calculate each sampling time point The concentration of the corresponding reactant A Concentration of reactant B The detection results were obtained after multiple cycles of changes in the reactants. In this case, because the flow rates of reactants A and B change at different periods, their corresponding concentrations... and It also varies with different periods, forming two distinguishable frequency components in the frequency domain. ,as well as, When the time-resolved Fourier transform infrared spectrometer 1 acquires infrared spectral data... Less than and To ensure phase resolution; The detection process ended after the system experienced several complete concentration change cycles. The detection results show each sampling time point... The corresponding infrared spectral data is a wavenumber. and absorbance Two-dimensional matrix data, i.e., any sampling time point There are multiple groups below As mentioned earlier, in infrared testing, It is obtained by directly outputting background spectral data. For details on infrared spectral data acquisition, data format, and its relationship with background spectral data, please refer to the relevant technical explanations; they will not be elaborated upon here.

[0053] S4, convert the detection results from time-dependent to phase-dependent to obtain the concentration conversion results and absorbance conversion results of each reactant; S4 is a time-phase conversion of the spectral-time data obtained in S3, using the periodic changes in the concentration of each reactant as a reference signal.

[0054] In one optional implementation, S4 includes: Get multiple custom phases ,in, The range of values ​​is ; Based on the corresponding conversion formula, the concentration of reactant A in the detection results is... Concentration of reactant B and absorbance According to each phase Transform them separately to obtain each phase. Under Dependency , , and ; The corresponding conversion formulas include: ; ; ; ; in, This represents the result of the concentration conversion of reactant A; This represents the result of the concentration conversion of reactant B; For The result is the periodic absorbance conversion. For The result is the periodic absorbance conversion. and These are the periods of change in the concentration of reactant A and the periods of change in the concentration of reactant B, respectively. This is the end time of the detection. It is understandable that each phase All can be obtained , , and This set of data.

[0055] S5. Determine the characteristic wavenumbers of multiple candidate intermediates and the main product of the reaction. For each characteristic wavenumber, extract the phase-dependent absorbance at that characteristic wavenumber from the absorbance conversion results of each reactant, and calculate its maximum intensity and its phase difference with the corresponding reactant concentration conversion results. Together, they form the calculation results of that characteristic wavenumber, thereby obtaining the calculation results of the candidate intermediates and the main product of the reaction. S5 is based on the phase-spectral data obtained in S4, which analyzes the characteristic wavenumbers of candidate intermediates and reaction main products.

[0056] (1) Candidate intermediates Based on the known mechanism or theoretical calculations of the reaction system, the characteristic wavenumbers corresponding to multiple candidate intermediates can be determined. Therefore, the process of obtaining the calculation results for the candidate intermediates includes the following steps: Step a1, for each candidate intermediate, the characteristic wavenumber From Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at and from Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at ; Understandably, with Absorbance conversion results for the periodicity and with Absorbance conversion results for the periodicity Each wavenumber contains absorbance values ​​corresponding to multiple wavenumbers; this step only requires selecting the characteristic wavenumber. The corresponding data is sufficient to obtain the characteristic wavenumber. The corresponding intermediate's absorption intensity as a function of phase under different reactant modulation conditions and .

[0057] Step a2, calculate maximum strength ,as well as maximum strength ; maximum strength Indicates characteristic wavenumber The amplitude of the absorption intensity of the corresponding intermediate under the modulation conditions of reactant A; Maximum intensity represents the characteristic wavenumber The amplitude of the absorption intensity of the corresponding intermediate under the modulation conditions of reactant B.

[0058] Step a3, Calculate Conversion results of reactant A concentration phase difference ,as well as Conversion results of reactant B concentration phase difference To obtain each characteristic wavenumber Data group As the corresponding intermediate The calculation results; Among them, phase difference Indicates characteristic wavenumber The phase difference of the corresponding intermediate under the modulation condition of reactant A, phase difference Indicates characteristic wavenumber The phase difference of the corresponding intermediate under the modulation conditions of reactant B.

[0059] (2) Main product of the reaction Based on the reaction objective, the main product and its characteristic wavenumber can be determined. The process for calculating the main product is the same as the process for calculating the intermediate, including the following steps: Step b1, targeting the characteristic wavenumbers corresponding to the main product of the reaction. From Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at and from Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at ; Step b2, calculate maximum strength ,as well as maximum strength ; Step b3, Calculate Conversion results of reactant A concentration phase difference ,as well as Conversion results of reactant B concentration phase difference The characteristic wavenumber is obtained. Data group As the main product of the reaction The calculation results.

[0060] The calculation results of each candidate intermediate and the main product obtained in S5 will serve as the data basis for subsequent intermediate source analysis, main-side reaction decoupling analysis, and intermediate formation sequence analysis.

[0061] S6. Based on the calculation results of each candidate intermediate and the main product of the reaction, perform intermediate source analysis, main and side reaction decoupling analysis, and intermediate formation sequence analysis.

[0062] The following are explanations: (1) Analysis of intermediate sources: Intermediate origin analysis determines the strength of the correlation between the intermediate and the reactants by comparing the amplitude of the absorption intensity of the intermediate corresponding to the characteristic wavenumber under different reactant modulation conditions, thereby determining the origin of the intermediate, that is, whether it comes from reactant A or reactant B, or whether it is an intermediate generated by the synergistic formation of reactants A and B.

[0063] Specifically, in S6, based on the calculation results of each candidate intermediate and the main reaction product, an intermediate source analysis is performed, including: For each intermediate In its calculation results, if the maximum strength Greater than maximum strength If the value exceeds at least one order of magnitude, then the intermediate is considered to be... The source of its formation is reactant A; if the maximum intensity Greater than maximum strength If the concentration exceeds at least one order of magnitude, then the intermediate is determined to originate from reactant B; if the maximum intensity... and maximum strength If they are of the same magnitude, then the intermediate is determined to be of that magnitude. The product originates from reactant A and reactant B, thus yielding each intermediate. The source analysis results.

[0064] (2) Decoupling analysis of main and side reactions: The decoupling analysis of main and side reactions uses the phase-amplitude response of the main product as a reference. By comparing the source characteristics (amplitude ratio) and the continuity of phase-frequency response of candidate intermediates in different reactant frequency channels, intermediates that respond with the periodic changes of reactants can be divided into main reaction channel intermediates and side reaction channel intermediates, thereby achieving decoupling of main and side reactions.

[0065] Specifically, in S7, based on the calculation results of each candidate intermediate and the main reaction product, a decoupling analysis of the main and side reactions is performed, including: For the main product of the reaction In its calculation results, if the maximum strength Greater than maximum strength If the intensity exceeds at least one order of magnitude, then the main reaction is determined to favor the pathway dominated by reactant A; if the maximum intensity... Greater than maximum strength If the value exceeds at least one order of magnitude, then the main reaction is determined to be biased towards the path dominated by reactant B, thus obtaining the main reaction biased path result. For each intermediate If the source analysis results are consistent with the main reaction biased pathway results, then the intermediate is preliminarily identified. It is an intermediate in the main reaction pathway; otherwise, it is preliminarily determined that this intermediate is... It is a side reaction pathway intermediate, and this intermediate is obtained. The primary determination result of the reaction pathway source; If the intermediate The source analysis results indicate that the phase difference in the calculation results originates from reactant A. Is it located in If it falls within the specified range, then the intermediate is preliminarily determined to be... It is a main reaction pathway intermediate; if not, this intermediate is preliminarily identified. It is a side reaction pathway intermediate, and this intermediate is obtained. The second determination result regarding the source of the reaction pathway; If the intermediate The source analysis results indicate that the phase difference in the calculation results originates from reactant B. Is it located in If it falls within the specified range, then the intermediate is preliminarily determined to be... It is a main reaction pathway intermediate; if not, this intermediate is preliminarily identified. It is a side reaction pathway intermediate, and this intermediate is obtained. The second determination result of the reaction channel source; wherein, the intermediate The source analysis results were obtained from the intermediate source analysis; When the intermediate When the sources determined by the first determination of the reaction channel source and the second determination of the reaction channel source are consistent, the intermediate is obtained. The final determination result of the reaction channel source is obtained, thereby obtaining the final determination result of the reaction channel source of each intermediate, and completing the decoupling analysis of the main and side reactions.

[0066] The intermediate Only when the first determination result of the reaction channel source and the second determination result of the reaction channel source are consistent can the consistent source be identified as the intermediate. The final determination of the source of the reaction channel (whether it is an intermediate in the main reaction channel or an intermediate in the side reaction channel) is crucial. Therefore, if the phase behavior of an intermediate with respect to reactant A or B is completely unrelated to the main product (e.g., the phase changes in the opposite direction with frequency, and the amplitude changes in a completely different trend), even if the amplitude is non-zero, it is very likely to belong to the side reaction channel.

[0067] (3) Analysis of intermediate generation order: Because different intermediates occupy different positions in the multi-reactant interface catalytic reaction network and are subject to different effective rate constants, their response time scales (effective time constants) to periodic perturbations of the same reactant concentration differ, resulting in different phase hysteresis angles at the same modulation frequency. Intermediate formation sequence analysis, based on determining the correspondence between intermediates and reactants, further utilizes phase difference information for signal decoupling and kinetic sequence analysis. By comparing and ranking the phase hysteresis of intermediates within a suitable frequency range, upstream and downstream intermediates can be distinguished, and the formation sequence and relative kinetic characteristics of each intermediate can be determined.

[0068] Specifically, in S7, based on the calculation results of each candidate intermediate and the main reaction product, an intermediate formation order analysis is performed, including: If the source analysis result of the intermediate is derived from reactant A, then the phase difference corresponding to reactant A in the calculation results of all intermediates should be considered. The intermediates are sorted in ascending order to characterize the order of formation of intermediates along the relevant channels of reactant A, thereby obtaining the analysis results of the intermediate formation order with reactant A as a reference. If the source analysis result of the intermediate is derived from reactant B, then the phase difference corresponding to reactant B in the calculation results of all intermediates should be considered. The intermediates are sorted in ascending order to characterize the order of formation of intermediates along the relevant pathways of reactant B, thus obtaining the analysis results of the intermediate formation order with reactant B as a reference.

[0069] Under the same reactant modulation conditions, the phase difference corresponding to the reactant in the calculation results of all intermediates represents the time lag of the formation process of each intermediate relative to the change in the concentration of the reactant. These phase differences are sorted in ascending order. The intermediates that are ranked earlier (with smaller phase lag) are determined to be the intermediates that were generated earlier in the reaction pathway, i.e., the intermediates that were generated earlier in the reaction pathway. The intermediates that are ranked later (with larger phase lag) are determined to be the intermediates that were generated later, i.e., the intermediates that were formed in subsequent conversion steps.

[0070] The embodiments of the present invention can integrate the results of intermediate source analysis, main-side reaction decoupling analysis, and intermediate formation sequence analysis to further analyze the interfacial catalytic reaction mechanism involving multiple reactants, including but not limited to: 1) Analysis of competitive and cooperative adsorption processes of different reactants at the interface; 2) Analysis of the order of formation, transformation and consumption of different intermediates along their respective reaction pathways; 3) Analysis of the master-controlling reaction steps and corresponding kinetic characteristics related to the formation of key intermediates.

[0071] As mentioned earlier, the inventor's previous patent application CN119595575A effectively amplified intermediate signals by periodically modulating the potential and combining it with lock-in amplification, achieving highly sensitive detection and kinetic analysis of intermediates. However, this method is mainly aimed at electrocatalytic and photoelectrocatalytic systems, and can only simultaneously amplify all potential-sensitive intermediate signals, making it difficult to distinguish the specific sources of different intermediates in multi-reactant systems and their contributions in multiple reaction pathways. In order to achieve effective decoupling of intermediate signals and accurate determination of their generation order, this invention proposes a multi-reactant catalytic intermediate tracing and kinetic decoupling method, applicable to intermediate tracing and decoupling in multi-reactant interfacial catalytic systems.

[0072] The primary objective of this invention is to establish an in-situ infrared online testing method based on phase-sensitive detection. By applying designed periodic variations to the concentrations of various reactants and converting time-dependent in-situ spectral data into phase-dependent spectral information, the method acquires the phase response of interfacial intermediates under different reactant periodic variation conditions while ensuring a high signal-to-noise ratio. This allows for the construction of a direct correspondence between "intermediate signal - periodic variation of each reactant," thereby achieving precise tracing of the intermediate generation source.

[0073] The second objective of this invention is to utilize the design of modulation periods and phase differences with different reactant concentrations so that intermediates directly related to different reactants exhibit distinguishable phase characteristics in the phase domain. By comparing and analyzing infrared spectra at different phase angles, the overlapping spectral signals between multiple intermediates, reactants, and products can be effectively decoupled, overcoming the shortcomings of existing methods in terms of insufficient signal separation capability for multi-reactant systems.

[0074] The third objective of this invention is to quantitatively characterize the response time scale and relative order of each intermediate relative to the periodic perturbations of different reactants by analyzing the law of change of signal intensity of each intermediate with phase angle, as well as the order and relative shift of phase angle of intermediates under different ratios and different periodic changes. This allows for the acquisition of the generation order and kinetic characteristics of multiple intermediates in the overall reaction network, providing experimental basis for the analysis of the mechanism of multi-reactant interface catalytic reaction and the determination of rate control steps.

[0075] In summary, the multi-reactant catalytic intermediate tracing and kinetic decoupling method provided in this invention, while inheriting the advantages of high sensitivity and high signal-to-noise ratio of the previously proposed phase-sensitive detection method (CN119595575A), introduces periodic modulation of multi-reactant concentrations and time-phase conversion analysis. This not only maintains the advantages of phase-sensitive technology in terms of signal-to-noise ratio and detection sensitivity, but also establishes a direct mapping relationship between "intermediate signal - multi-reactant periodic change" by designing differentiated periodic change characteristics for different reactants. This enables precise tracing of intermediate sources, effective decoupling of main and side-reaction intermediates, and quantitative determination of the generation sequence and kinetic characteristics of intermediates in the main reaction channel within complex multi-reactant systems. Thus, it solves the key challenges of intermediate research in complex multi-reactant interface catalytic systems in existing technologies.

[0076] It should be noted that in the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for tracing and decoupling the kinetics of multi-reactant catalytic intermediates, characterized in that, include: S1, Build an in-situ infrared online testing system for phase-sensitive detection of multiple reactants; S2, identify multiple reactants and design different concentration change patterns for each reactant over different periods; S3. Based on the system, after completing the background spectral data acquisition, the detection is started, so that the concentration of each reactant changes periodically according to its own concentration change mode. At the same time, infrared spectral data at each sampling time point are collected, including the absorbance corresponding to the wavenumber, and the reactant concentration at each sampling time point is calculated to obtain the detection results after multiple periodic changes. S4, convert the detection results from time-dependent to phase-dependent to obtain the concentration conversion results and absorbance conversion results of each reactant; S5. Determine the characteristic wavenumbers of multiple candidate intermediates and the main product of the reaction. For each characteristic wavenumber, extract the phase-dependent absorbance at that characteristic wavenumber from the absorbance conversion results of each reactant, and calculate its maximum intensity and its phase difference with the corresponding reactant concentration conversion results. Together, they form the calculation results of that characteristic wavenumber, thereby obtaining the calculation results of the candidate intermediates and the main product of the reaction. S6. Based on the calculation results of each candidate intermediate and the main product of the reaction, perform intermediate source analysis, main and side reaction decoupling analysis, and intermediate formation sequence analysis.

2. The method according to claim 1, characterized in that, The multi-reactant phase-sensitive detection in-situ infrared online testing system includes: In-situ infrared spectroscopy acquisition unit, reaction unit, control unit, and data acquisition and processing unit; wherein: The in-situ infrared spectroscopy acquisition unit is used to acquire time-resolved infrared spectral data of the reaction interface in real time during the reaction process. The reaction unit is located in the in-situ infrared spectroscopy acquisition unit and is used to contain reactants and form a reaction environment. The control unit is used to control the reactant concentration by controlling the reactant flow rate according to the concentration change pattern of each reactant in different cycles, and to realize inter-system control. The data acquisition and processing unit is used to record time data, spectral data, calculate concentration data, and perform related calculations and analysis.

3. The method according to claim 2, characterized in that, In S2, different concentration change patterns are designed for each reactant over different periods, including: Waveform functions with different periods are designed for each reactant to indicate the periodic changes in reactant concentration, wherein the waveform functions include sine waves, square waves, and step waves.

4. The method according to claim 3, characterized in that, The control unit includes a flow control system, a function waveform generator, and a trigger controller; The flow control system includes flow controllers corresponding to the reactants. The function waveform generator is used to generate pre-designed waveform functions for each reactant and output them to the corresponding flow controllers in the flow control system, so that the flow controllers can control the flow according to the given waveform functions to achieve concentration control. The trigger controller is also used to realize the synchronous operation of the in-situ infrared spectroscopy acquisition unit, the flow control system, the function waveform generator and the data acquisition and processing unit.

5. The method according to claim 3, characterized in that, The multiple reactants include reactant A and reactant B; In S3, the process of obtaining detection results after multiple periodic changes includes: After the detection is initiated, the concentration of reactant A is periodically adjusted according to its waveform function. The concentration of reactant B undergoes periodic changes, varying periodically according to its waveform function. The system undergoes periodic changes and adjusts the concentration of the inert gas to maintain a steady-state baseline in real time; among which, ; After the detection is started, it is synchronized at a preset sampling interval. Collect data at each sampling time point. The infrared spectral data were recorded, and each sampling time point was recorded. And calculate each sampling time point The concentration of the corresponding reactant A Concentration of reactant B The detection results were obtained after multiple cycles of reactant changes, among which, Less than and ; Each sampling time point The corresponding infrared spectral data is a wavenumber. and absorbance Two-dimensional matrix data.

6. The method according to claim 5, characterized in that, S4 includes: Get multiple custom phases ,in, The range of values ​​is ; Based on the corresponding conversion formula, the concentration of reactant A in the detection results is... Concentration of reactant B and absorbance According to each phase Transform them separately to obtain each phase. Under Dependency , , and ; The corresponding conversion formulas include: ； ； ； ； in, This represents the result of the concentration conversion of reactant A; This represents the result of the concentration conversion of reactant B; For The result is the periodic absorbance conversion. For The result is the periodic absorbance conversion. and These are the periods of change in the concentration of reactant A and the periods of change in the concentration of reactant B, respectively. This is the end time of the detection.

7. The method according to claim 6, characterized in that, In S5: The process of obtaining the computational results of candidate intermediates includes: For the feature wavenumber corresponding to each candidate intermediate From Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at and from Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at ; calculate maximum strength ,as well as maximum strength ; calculate Conversion results of reactant A concentration phase difference ,as well as Conversion results of reactant B concentration phase difference To obtain each characteristic wavenumber Data group As the corresponding intermediate The calculation results; The process of obtaining the calculated results for the main product of the reaction includes: For the characteristic wavenumbers corresponding to the main product of the reaction From Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at and from Absorbance conversion results for the periodicity Extracting the characteristic wavenumber Phase-dependent absorbance at ; calculate maximum strength ,as well as maximum strength ; calculate Conversion results of reactant A concentration phase difference ,as well as Conversion results of reactant B concentration phase difference The characteristic wavenumber is obtained. Data group As the main product of the reaction The calculation results.

8. The method according to claim 7, characterized in that, In S6, based on the calculation results of each candidate intermediate and the main reaction product, an intermediate source analysis is performed, including: For each intermediate In its calculation results, if the maximum strength Greater than maximum strength If the value exceeds at least one order of magnitude, then the intermediate is considered to be... The source of its formation is reactant A; if the maximum intensity Greater than maximum strength If the concentration exceeds at least one order of magnitude, then the intermediate is determined to originate from reactant B; if the maximum intensity... and maximum strength If they are of the same magnitude, then the intermediate is determined to be of that magnitude. The product originates from reactant A and reactant B, thus yielding each intermediate. The source analysis results.

9. The method according to claim 8, characterized in that, In S6, based on the calculation results of each candidate intermediate and the main reaction product, a decoupling analysis of the main and side reactions is performed, including: For the main product of the reaction In its calculation results, if the maximum strength Greater than maximum strength If the intensity exceeds at least one order of magnitude, then the main reaction is determined to favor the pathway dominated by reactant A; if the maximum intensity... Greater than maximum strength If the value exceeds at least one order of magnitude, then the main reaction is determined to be biased towards the path dominated by reactant B, thus obtaining the main reaction biased path result. For each intermediate If the source analysis results are consistent with the main reaction biased pathway results, then the intermediate is preliminarily identified. It is an intermediate in the main reaction pathway; otherwise, it is preliminarily determined that this intermediate is... It is a side reaction pathway intermediate, and this intermediate is obtained. The primary determination result of the reaction pathway source; If the intermediate The source analysis results indicate that the phase difference in the calculation results originates from reactant A. Is it located in If it falls within the specified range, then the intermediate is preliminarily determined to be... It is a main reaction pathway intermediate; if not, this intermediate is preliminarily identified. It is a side reaction pathway intermediate, and this intermediate is obtained. The second determination result regarding the source of the reaction pathway; If the intermediate The source analysis results indicate that the phase difference in the calculation results originates from reactant B. Is it located in If it falls within the specified range, then the intermediate is preliminarily determined to be... It is a main reaction pathway intermediate; if not, this intermediate is preliminarily identified. It is a side reaction pathway intermediate, and this intermediate is obtained. The second determination result regarding the source of the reaction pathway; When the intermediate When the sources determined by the first determination of the reaction channel source and the second determination of the reaction channel source are consistent, the intermediate is obtained. The final determination result of the reaction channel source is obtained, thereby obtaining the final determination result of the reaction channel source of each intermediate, and completing the decoupling analysis of the main and side reactions.

10. The method according to claim 9, characterized in that, In S6, based on the calculation results of each candidate intermediate and the main reaction product, an intermediate formation order analysis is performed, including: If the source analysis result of the intermediate is derived from reactant A, then the phase difference corresponding to reactant A in the calculation results of all intermediates should be considered. The intermediates are sorted in ascending order to characterize the order of formation of intermediates along the relevant channels of reactant A, thereby obtaining the analysis results of the intermediate formation order with reactant A as a reference. If the source analysis result of the intermediate is derived from reactant B, then the phase difference corresponding to reactant B in the calculation results of all intermediates should be considered. The intermediates are sorted in ascending order to characterize the order of formation of intermediates along the relevant pathways of reactant B, thus obtaining the analysis results of the intermediate formation order with reactant B as a reference.

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