Stepwise Reaction Research Articles

Regulating catalytic activity of C2N for the CO oxidation by N2O via deposition of metallic elements: A density functional theory study

Converting N2O and CO into harmless gases is an effective solution for several environmental issues. We investigate the catalytic activity of C2N deposited with Al, Fe and Co for the CO oxidation by N2O by density functional theory (DFT) calculations. In this work, we pondered different adsorption sites of C2N such as N-terminal, C-terminal, and metal-terminal. The reaction pathways and energy barriers of two mechanisms: stepwise adsorption and co-adsorption, are scrutinized and compared. Moreover, the O-terminal and N-terminal pathways for N2O adsorption are pondered. The result indicate that deposited metals greatly decrease the reaction energy barrier for the rate-determining step in both the stepwise and co-adsorption reaction mechanisms. In addition, the stepwise adsorption mechanism is more likely to occur than the co-adsorption mechanism. Al@C2N exhibits the best catalytic effect in the stepwise adsorption mechanism and its energy barrier of the rate-determining step is only 1.08 kcal/mol. Fe@C2N shows superior catalytic activity in the co-adsorption mechanism, and its highest energy barrier is 12.62 kcal/mol.

Theoretical Insights into Excited‐State Stepwise Double Proton Transfer Associated with Solvent Polarity for 2‐bis(benzothia‐zolyl)naphthalene‐Diol Compound

AbstractInspired by the excellent photochemical properties of 2‐(2′‐hydroxyphenyl)benzazole and its derivatives, in this work, the novel 2‐bis(benzothia‐zolyl)naphthalene‐diol (2‐BBTND) fluorophore is explored about its photo‐induced behaviors. The intramolecular double hydrogen bonding interaction and the excited state intramolecular double proton transfer (ESDPT) behavior of 2‐BBTND fluorophore are investigated in combination with different polar solvent environments. From the structural changes and charge recombination induced by photoexcitation, we can affirm that strong polar solvent environment promotes the excited state dynamical reaction for 2‐BBTND compound. By constructing potential energy surfaces (PESs) in S0 and S1 states, we clarify that 2‐BBTND fluorophore should undergo the stepwise ESDPT reaction after photoexcitation. Combined with the size of potential energy barriers along with reaction paths in different solvents, we finally propose a new solvent‐polarity‐dependent stepwise ESDPT for 2‐BBTND fluorophore.

Unexpected Li displacement and suppressed phase transition enabling highly stabilized oxygen redox in P3-type Na layered oxide cathode

Oxygen redox is considered a new paradigm for increasing the practical capacity and energy density of the layered oxide cathodes for Na-ion batteries. However, severe local structural changes and phase transitions during anionic redox reactions lead to poor electrochemical performance with sluggish kinetics. Here, we propose a synergy of Li-Cu cations in harnessing the full potential of oxygen redox, through Li displacement and suppressed phase transition in P3-type layered oxide cathode. P3-type Na0.7[Li0.1Cu0.2Mn0.7]O2 cathode delivers a large specific capacity of ∼212 mA h g−1 at 15 mA g−1. The discharge capacity is maintained up to ∼90% of the initial capacity after 100 cycles, with stable occurrence of the oxygen redox in the high-voltage region. Through advanced experimental analyses and first-principles calculations, it is confirmed that a stepwise redox reaction based on Cu and O ions occurs for the charge-compensation mechanism upon charging. Based on a concrete understanding of the reaction mechanism, the Li displacement by the synergy of Li-Cu cations plays a crucial role in suppressing the structural change of the P3-type layered material under the oxygen redox reaction, and it is expected to be an effective strategy for stabilizing the oxygen redox in the layered oxides of Na-ion batteries.

TEMPO‐Oxidized Cellulose Nanofibers as Pseudocatalysts for in Situ and on‐Demand Hydrogen Generation via Aluminum Powder/Pure Water Reactions at a Temperature below 50 °C

Cellulose nanofibers (CNFs) prepared via 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)‐mediated oxidation of the C6 primary hydroxyls of native cellulose to carboxylates are used as pseudocatalysts for enhancing the aluminum powder/pure water reactions. The Al powder/pure water reaction is a stepwise reaction. It starts from hydration of the outmost native Al2O3 thin layer and then the reaction of the inner metallic Al with water. At lower temperatures (<50 °C), OH− and Al3+ ions are the preliminary products of the native Al2O3 thin layer hydration. Once Al powders are mixed with pure water containing 0.1–0.5 wt% TEMPO‐CNFs, condensed networks consisting of TEMPO‐CNFs self‐establish over the native Al2O3 thin layer. Al3+ ions are captured by TEMPO‐CNFs via the formation of insoluble Al3+/TEMPO‐CNFs complexing nanostructures and the conjugated OH− ions are being restricted nearby the native Al2O3‐based thin layer via electrostatic repulsion. A highly alkaline condition (pH > 11) is dynamically generated, and as a result, the native Al2O3 thin layer dissolves rapidly via the reaction with OH− ions. The OH− ions function also as catalysts, accelerating the reaction of metallic Al with water. Al powders (2–200 μm) react promptly and a nearly 100% Al/H2 conversion is obtained at the reaction temperature below 50 °C.

Selective Nsp2 - and Csp2 - Photografting of Au-Surface by Aryldiazonium Salts and Arylazo Sulfonates.

Arylazo sulfonates (Ar-N=N-SO3 Na) have been found to undergo photografting on gold surface through both Au-Nsp2 - and Au-Csp2 - bond formation. The functionalized materials have been fully characterized by infrared reflection absorption spectroscopy (IRRAS), Raman, XPS, DFT calculations and UV-Vis absorption spectroscopy. These methods permit to evidence aromatic substituents (IRRAS), the Au-N=N signature (Raman and XPS spectroscopy), and the bond dissociation energy values of the two linkages (DFT calculation). The grafting proceeds through two competitive paths, namely a stepwise reaction involving an aryl radical (for the formation of the Au-Ar bonds) and a concerted reaction on the surface of gold (for Au-N=N-Ar bond formation). The occurrence of an aryl radical upon irradiation has been fully evidenced by EPR spectroscopy. Finally, E/Z photoisomerisation of the N=N bonds present on prepared few layer films has been observed by means of UV-Vis absorption spectroscopy.

Unimolecular Reactivity of [Cu(R)(CF3 )3 ]- Complexes (R=Organyl): Stepwise versus Concerted Mechanism in Copper-Mediated Trifluoromethylation.

The cuprate complexes [Cu(R)(CF3 )3 ]- (R=organyl) offer an efficient synthetic access to valuable trifluoromethylation products RCF3 . Here, electrospray-ionization mass spectrometry is used to analyze the formation of these intermediates in solution and probe their fragmentation pathways in the gas phase. Furthermore, the potential energy surfaces of these systems are explored by quantum chemical calculations. Upon collisional activation, the [Cu(R)(CF3 )3 ]- complexes (R=Me, Et, Bu, s Bu, allyl) afford the product ions [Cu(CF3 )3 ]⋅- and [Cu(CF3 )2 ]- . The former obviously results from an R⋅ loss, whereas the latter originates either from the stepwise release of R⋅ and CF3 ⋅ radicals or a concerted reductive elimination of RCF3 . The gas-phase fragmentation experiments as well as the quantum chemical calculations indicate that the preference for the stepwise reaction toward [Cu(CF3 )2 ]- increases with the stability of the formed organyl radical R⋅. This finding suggests that the recombination of R⋅ and CF3 ⋅ radicals may possibly contribute to the formation of RCF3 from [Cu(R)(CF3 )3 ]- in synthetic applications. In contrast, the [Cu(R)(CF3 )3 ]- complexes (R=aryl) only yield [Cu(CF3 )2 ]- when subjected to collision-induced dissociation. These species exclusively undergo a concerted reductive elimination because the competing stepwise pathway is disfavored by the low stability of aryl radicals.

The Diels–Alder Reaction between Euparin and Dimethyl Acetylenedicarboxylate; a Joint Experimental and Density Functional Theory Study

In this project, we have investigated the Diels–Alder (DA) reaction between euparin (as a natural furan derivative) and dimethyl acetylenedicarboxylate (DMAD) as an electrophilic acetylene. The experimental observations during the reaction in different conditions showed that the yield and the rate of the process would increase with increasing the polarity of the solvent. Such observation suspected us that like several recent reports, the mechanism of this DA reaction takes place through a stepwise route containing a zwitterionic intermediate or at least through a relatively polar transition state (TS). Next, during the density functional theory (DFT) studies and the potential energy surface (PES) investigations, we have detected a stepwise reaction pathway in parallel with the one-step route. The results of this work are in agreement with the recent reports about the competition between the one-step and multisteps routes in the DA reactions.

Unveiling and regulating the solvent-polarity-associated excited state intramolecular double proton transfer behavior for 1-bis(benzothiazolyl)naphthalene-diol fluorophore

Inspired by the regulatory luminescence properties of HBT derivatives, in this work, we mainly conduct a detailed theoretical exploration on the photoinduced excitation behavior of a novel di-proton-transfer type HBT derivative 1-bis(benzothiazolyl)naphthalene-diol (1-BBTND). The intramolecular double hydrogen bonding interaction and the excited state intramolecular double proton transfer (ESDPT) behavior of 1-BBTND fluorophore are investigated in combination with different polar solvent environments. From the structural changes and charge recombination induced by photoexcitation, we can conclude that strong polar solvent environment promotes the excited state dynamical reaction for 1-BBTND compound. By constructing potential energy surfaces (PESs) in S0 and S1 states, we clarify that 1-BBTND fluorophore should undergo a stepwise ESDPT reaction after photoexcitation. Combined with the size of potential energy barriers along with reaction paths in different solvents, we finally propose a new solvent-polarity-dependent stepwise ESDPT for 1-BBTND fluorophore.

Bis-indole based triazine derivatives: Synthesis, characterization, in vitro β-glucuronidase anti-cancer and anti-bacterial evaluation along with in silico molecular docking and ADME analysis

The present work described the synthetic procedure adopted for the synthesis of bis-indole-based triazine derivatives via a series of reactions. All the compounds were synthesized through a stepwise reaction. After being confirmation through thin-layer chromatography (TLC) these compounds were characterized through various spectroscopic techniques including 1HNMR, 13CNMR and HREI-MS and evaluated against beta-glucuronidase in the presence of standard drug D-saccharic acid 1,4 lactone (IC50 = 31.2 ± 1.0 µM). Most of the synthesized derivatives were found with better to good inhibitory potentials (IC50 = 5.30 ± 2.0 µM to 33.10 ± 1.0 µM). SAR explains better results of analogs due to the presence of varied substituents on the aromatic rings. In this regard, the excellent potential was shown by analogs 1, 3, 6, 8 and 9 with IC50 = 5.30 ± 2.0, 7.10 ± 4.0, 6.10 ± 3.0, 8.40 ± 1.0 and 7.20 ± 3.0 µM respectively). In addition, all the synthesized analogs were evaluated for anti-cancer and anti-bacterial (E. coli) activities in which the targeted compounds were found with significant potentials in the presence of standard drugs Tetrandrineb (IC50 = 1.37 ± 0.10 µM) and streptomycin respectively. These derivatives were further subjected to molecular docking studies in order to investigate better binding sites with distance. Additionally, ADME properties for the synthesized compounds were also explored the drug like properties of the synthesized compounds.

Analysis of the aging effects on the thermal runaway characteristics of Lithium-Ion cells through stepwise reactions

The current political vision to drastically reduce carbon emissions pushes the electrified powertrain into an increasingly important role in the transport sector. However, concerns related to the battery's effectiveness as an energy source need to be overcome to make this technology widespread. One such concern is safety, catching attention as development races towards greater battery energy density. In this way, cathodic chemistry is important since exothermic reactions are unleashed from the components that originally formed the active material. Furthermore, the aging process reduces the battery capacity, reducing the amount of active material and thickening the solid electrolyte interface, which increases the joule effect. For these reasons, thermal runaway under aging conditions must be investigated to assess potential safety issues. Using an accelerating rate colorimeter, the heat-induced thermal runaway tests were performed with two-cathode chemistry (NMC and LFP) under pristine and aged battery conditions. For aging the batteries, the ARC was coupled with a bidirectional source. Two ambient temperatures, 20 °C and 50 °C, were used for the aging tests, being the batteries cycled up to 250 cycles with a determined protocol for charge and discharge. A numerical model was fed with experimental tests, targeting optimizing the battery output parameters and obtaining geometric aspects that are difficult to measure. Unlike the single step model, a stepwise reactions model was created to assess the heat release from different battery components for pristine and aged conditions. The higher endothermic behavior from cathode decomposition and less oxygen released during this reaction make the LFP battery safer than the NMC. For aged batteries, the SEI growth consumes lithium and electrolyte, decreasing the quantity of both components in the anode. Thus, the anode and electrolyte reaction after SEI decomposition is lower, improving battery safety.

Gelation Time of Network-Forming Polymer Solutions with Reversible Cross-Link Junctions of Variable Multiplicity.

The gelation time tg necessary for a solution of functional (associating) molecules to reach its gel point after a temperature jump, or a sudden concentration change, is theoretically calculated on the basis of the kinetic equation for the stepwise cross-linking reaction as a function of the concentration, temperature, functionality f of the molecules, and multiplicity k of the cross-link junctions. It is shown that quite generally tg can be decomposed into the product of the relaxation time tR and a thermodynamic factor Q. They are functions of a single scaled concentration x≡λ(T)ϕ, where λ(T) is the association constant and ϕ is the concentration. Therefore, the superposition principle holds with λ(T) as a shift factor of the concentration. Additionally, they all depend on the rate constants of the cross-link reaction, and hence it is possible to estimate these microscopic parameters from macroscopic measurements of tg. The thermodynamic factor Q is shown to depend on the quench depth. It generates a singularity of logarithmic divergence as the temperature (concentration) approaches the equilibrium gel point, while the relaxation time tR changes continuously across it. Gelation time tg obeys a power law tg-1∼xn in the high concentration region, whose power index n is related to the multiplicity of the cross-links. The retardation effect on the gelation time due to the reversibility of the cross-linking is explicitly calculated for some specific models of cross-linking to find the rate-controlling steps in order for the minimization of the gelation time to be easier in the gel processing. For a micellar cross-linking covering a wide range of the multiplicity, as seen in hydrophobically-modified water-soluble polymers, tR is shown to obey a formula similar to the Aniansson-Wall law.

Synthesis of a Hybrid Composed of Anisotropic Niobate Layers Modified with MoC Nanoparticles.

The hybrid composed of anisotropic niobate layers modified with MoC nanoparticles is synthesized by multistep reactions. The stepwise interlayer reactions for layered hexaniobate induce selective surface modification at the alternate interlayers, and the following ultrasonication leads to the formation of double-layered nanosheets. The further liquid phase MoC deposition with the double-layered nanosheets leads to the decoration of MoC nanoparticles on the surfaces of the double-layered nanosheets. The new hybrid can be regarded as a stacking of the two layers with anisotropically modified nanoparticles. The relatively high temperature in the MoC synthesis causes partial leaching of the grafted phosphonate groups. The exposed surface of the niobate nanosheets due to the partial leaching may interact with MoC to succeed in the hybridization. The hybrid after heating exhibits photocatalytic activity, indicating that this hybridization method can be useful for hybrid synthesis of semiconductor nanosheets and co-catalyst nanoparticles toward photocatalytic application.

Ambient Preparation of Benzoxazine-based Phenolic Resins Enables Long-term Sustainable Photosynthesis of Hydrogen Peroxide.

Rational design of polymer structures at the molecular level promotes the iteration of high-performance photocatalyst for sustainable photocatalytic hydrogen peroxide (H2 O2 ) production from oxygen and water, which also lays the basis for revealing the reaction mechanism. Here we report a benzoxazine-based m-aminophenol-formaldehyde resin (APFac) polymerized at ambient conditions, exhibiting superior H2 O2 yield and long-term stability to most polymeric photocatalysts. Benzoxazine structure was identified as the crucial photocatalytic active segment in APFac. Favorable adsorption of oxygen/intermediates on benzoxazine structure and commendable product selectivity accelerated the reaction kinetically in stepwise single-electron oxygen reduction reaction. The proposed benzoxazine-based phenolic resin provides the possibility of production in batches and industrial application, and sheds light on the de novo design and analysis of metal-free polymeric photocatalysts.

SARS-CoV-2 polyprotein substrate regulates the stepwise Mpro cleavage reaction

The processing of the Coronavirus polyproteins pp1a and pp1ab by the main protease Mpro to produce mature proteins is a crucial event in virus replication and a promising target for antiviral drug development. Mpro cleaves polyproteins in a defined order, but how Mpro and/or the polyproteins determine the order of cleavage remains enigmatic due to a lack of structural information about polyprotein-bound Mpro. Here, we present the cryo-EM structures of SARS-CoV-2 Mpro in an apo form and in complex with the nsp7-10 region of the pp1a polyprotein. The complex structure shows that Mpro interacts with only the recognition site residues between nsp9 and nsp10, without any association with the rest of the polyprotein. Comparison between the apo form and polyprotein-bound structures of Mpro highlights the flexible nature of the active site region of Mpro, which allows it to accommodate 10 recognition sites found in the polyprotein. These observations suggest that the role of Mpro in selecting a preferred cleavage site is limited and underscore the roles of the structure, conformation and/or dynamics of the polyproteins in determining the sequence of polyprotein cleavage by Mpro.

One-Bond-Nucleophilicity and -Electrophilicity Parameters: An Efficient Ordering System for 1,3-Dipolar Cycloadditions.

Diazoalkanes are ambiphilic 1,3-dipoles that undergo fast Huisgen cycloadditions with both electron-rich and electron-poor dipolarophiles but react slowly with alkenes of low polarity. Frontier molecular orbital (FMO) theory considering the 3-center-4-electron π-system of the propargyl fragment of diazoalkanes is commonly applied to rationalize these reactivity trends. However, we recently found that a change in the mechanism from cycloadditions to azo couplings takes place due to the existence of a previously overlooked lower-lying unoccupied molecular orbital. We now propose an alternative approach to analyze 1,3-dipolar cycloaddition reactions, which relies on the linear free energy relationship lg k2(20 °C) = sN(N + E) (eq 1) with two solvent-dependent parameters (N, sN) to characterize nucleophiles and one parameter (E) for electrophiles. Rate constants for the cycloadditions of diazoalkanes with dipolarophiles were measured and compared with those calculated for the formation of zwitterions by eq 1. The difference between experimental and predicted Gibbs energies of activation is interpreted as the energy of concert, i.e., the stabilization of the transition states by the concerted formation of two new bonds. By linking the plot of lg k2 vs N for nucleophilic dipolarophiles with that of lg k2 vs E for electrophilic dipolarophiles, one obtains V-shaped plots which provide absolute rate constants for the stepwise reactions on the borderlines. These plots furthermore predict relative reactivities of dipolarophiles in concerted, highly asynchronous cycloadditions more precisely than the classical correlations of rate constants with FMO energies or ionization potentials. DFT calculations using the SMD solvent model confirm these interpretations.

The effects of 4,6-Dichloro-2-Sodiooxy-1,3,5-Triazine on the Fibrillation Propensity of Lyocell Fibers

ABSTRACT Dichlorotriazine reactive crosslinker has been used to reduce the fibrillation of Lyocell. The fibrillation propensity and mechanism of 4, 6-dichloro-2-sodium dioxy-1, 3, 5-triazine treatment on Lyocell fibers were studied, and the mechanical properties and dyeing properties of the treated Lyocell fibers were evaluated. The results showed that the three-step reaction process can make lyocell have more uniform behavior of decreased fibrillation propensity, in which the first step is physical mixing of triazine and cellulose, the second and third steps are the stepwise reactions of cellulose with two chlorines of Dichlorotriazine under different conditions, respectively. At the end of the reaction, non-fibrillating Lyocell fibers were produced. In addition, the structure, mechanical properties and dyeing properties of the Lyocell fibers were not affected by the cross-linking chemical reaction process. In conclusion, this study provides a better uniform effect and economically reasonable route for the preparation of commercial non-fibrillating Lyocell fibers.

Organopolysulfides as high-performance cathode materials for rechargeable aluminum-ion batteries

The development of aluminum-ion batteries (AIBs) is significantly confined by the limited high-performance cathode materials. Herein, organopolysulfides are investigated as active cathode materials to fabricate AIBs. A liquid-phase phenyl tetrasulfide (PTS) can deliver a capacity above 600 mAh g−1 after activation, with the maintenance of 253 mAh g−1 after 100 cycles. Owing to the different S locations, PTS shows several voltage plateaus and an average voltage of ∼0.7 V vs. Al3+/Al with no decay upon cycling. More importantly, the liquid PTS can serve as a high-Coulombic-efficiency cathode (∼99.88% ± 0.57% after stabilization), enlighting the design of high-efficiency and low-resistance conversion-type cathode materials for AIBs. By experimental characterizations accompanied by theoretical calculations, it is found that PTS undergoes stepwise reaction procedures during discharge with final products of Al2S3 and AlCl2-coordinated phenyl sulfide, and partially reforms with elemental S and other organopolysulfides during charge. This study demonstrates new opportunities for the design of high-efficiency conversion-type cathode materials for advanced AIBs.

Nitrile Oxide, Alkenes, Dipolar Cycloaddition, Isomerization and Metathesis Involved in the Syntheses of 2-Isoxazolines.

The involvement of 1,3-dipolar cycloaddition (1,3-DP), double bond migration, metathesis, and nitrile oxide (including in situ-generated nitrile oxide) as dipoles, together with the C=C bond containing dipolarophiles, in the syntheses of 2-isoxazolines is presented. Methods for synthesizing isoxazolines (other than 1,3-DP cycloaddition) were also presented briefly. Various methods of nitrile oxide preparation, especially in situ-generated procedures, are presented. Special attention was paid to the application of various combinations of 1,3-DP cycloaddition with double bond migration (DBM) and with alkene metathesis (AM) in the syntheses of trisubstituted isoxazolines. Allyl compounds of the type QCH2CH=CH2 (Q = ArO, ArS, Ar, and others) play the role of dipolarophile precursors in the combinations of DPC mentioned, DBM and AM. Mechanistic aspects of cycloadditions, i.e., concerted or stepwise reaction mechanism and their regio- and stereoselectivity are also discussed from experimental and theoretical points of view. Side reactions accompanying cycloaddition, especially nitrile oxide dimerization, are considered. 2-Isoxazoline applications in organic synthesis and their biological activity, broad utility in medicine, agriculture, and other fields were also raised. Some remaining challenges in the field of 1,3-DP cycloaddition in the syntheses of isoxazolines are finally discussed.

Synthesis of Nanoscale Zero-Valent Iron with Polyphenol Extract from Cloves (Syzygium aromaticum) Through a Stepwise Reaction and Adsorption Test on Pb(II)

Polyphenols from clove extract (Syzygium aromaticum) were successfully used as reducing agents to synthesize nanoscale zero-valent iron (nZVI). Optimization of nZVI synthesis was carried out by reacting polyphenols and FeSO4 at a composition of 0.25:4.75, 1:4, 2:3, and 3:2. The particle size analyzer showed that the smaller particle size distribution was obtained at nZVI 0.25:4.75, with values of D10 = 85.1 nm, D50 = 122 nm, and D90 = 175 nm. The results of the Pb(II) removal test showed that nZVI 0.25:4.75 had a fairly high percentage of Pb(II) removal, which was 96.4852% at 60 minutes. The smaller particle size of nZVI 0.25:4.75 compared to other samples is an important factor affecting the adsorption activity of Pb(II) in an aqueous medium.

Selective dechlorination degradation of chlorobenzenes by dual single-atomic Fe/Ni catalyst with M-N/M-O active sites synergistic

Removal and detoxification of chlorobenzenes have attracted public concern, multiple active sites single-atom Fe and single-atom Ni composite nitrogen-doped graphene (FeSA/CN/NiSA) cathode catalyst supplied generation and adsorption capacity of hydrogen and hydroxyl active species. M-O active sites coupled with M-N improved activity and stability of the catalyst, and decreased bond breaking energy barrier of C-Cl, FeSA/CN/NiSA-NiF cathode showed superior removal performance of chlorinated aromatic hydrocarbons (monochlorobenzene: 98.9%, dichlorobenzene: over 90.4%, trichlorobenzene: over 85.7%) and selectivity. Chlorobenzenes were dechlorinated under low stepwise voltage on the FeSA/CN/NiSA-NiF cathode. The efficiencies of stepwise dechlorination reactions of chlorobenzenes were all above 76%, Faradaic efficiencies were above 71.8%. The FeSA/CN/NiSA-NiF cathode was not sensitive to the molecular structure and has overcome the high energy barrier of chlorobenzenes molecular structure. The electrophilic attack of H*ads formed hyperconjugation bond weakened the possibility of the Cl atom forming a bond with the benzene ring, and was favorable for the Cl position to achieve single-electron transfer dechlorination. The selective stepwise dechlorination degradation of chlorobenzenes by FeSA/CN/NiSA-NiF cathode with multiple active sites demonstrated the advantaged performance of M-O and M-N active sites coupled synergistic in electrochemical reduction and degradation, providing a strategy for product-selective degradation of chlorinated aromatic hydrocarbons.