Stereoselective Research Articles

Enhanced CO2 Reduction on a Cu-Decorated Single-Atom Catalyst via an Inverse Sandwich M-Graphene-Cu Structure.

The highly active and selective electrochemical CO2 reduction reaction (CO2RR) can be exploited to produce valuable chemicals and fuels and is also crucial for achieving clean energy goals and environmental remediation. Decorated single-atom catalysts (D-SACs), which feature synergistic interactions between the active metal site (M) and an axially decorated ligand, have been extensively explored for the CO2RR. Very recently, novel double-atom catalysts (DACs) featuring inverse sandwich structures were theoretically proposed and identified as promising CO2RR electrocatalysts. However, the experimental synthesis of DACs remains a challenge. To facilitate the fabrication and to realize the potential of these novel DACs, we designed a D-SAC system, denoted as M1@gra+Cuslab. This system features a graphene layer with a vacancy-anchored SAC, all stacked on a Cu(111) surface, thereby embodying a Cu slab-supported inverse sandwich M-graphene-Cu structure. Using density functional theory calculations, we evaluated the stability, selectivity, and activity of 27 M1@gra+Cuslab systems (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, or Au) and showed five M1@gra+Cuslab (M = Co, Ni, Cu, Rh, or Pd) systems exhibit optimal characteristics for the CO2RR and can potentially outperform their SAC and DAC counterparts. This study offers a new strategy for developing highly efficient CO2RR D-SACs with an inverse sandwich structural moiety.

Excimer-ultraviolet-lamp-assisted selective etching of single-layer graphene and its application in edge-contact devices

Since the discovery of graphene and its remarkable properties, researchers have actively explored advanced graphene-patterning technologies. While the etching process is pivotal in shaping graphene channels, existing etching techniques have limitations such as low speed, high cost, residue contamination, and rough edges. Therefore, the development of facile and efficient etching methods is necessary. This study entailed the development of a novel technique for patterning graphene through dry etching, utilizing selective photochemical reactions precisely targeted at single-layer graphene (SLG) surfaces. This process is facilitated by an excimer ultraviolet lamp emitting light at a wavelength of 172 nm. The effectiveness of this technique in selectively removing SLG over large areas, leaving the few-layer graphene intact and clean, was confirmed by various spectroscopic analyses. Furthermore, we explored the application of this technique to device fabrication, revealing its potential to enhance the electrical properties of SLG-based devices. One-dimensional (1D) edge contacts fabricated using this method not only exhibited enhanced electrical transport characteristics compared to two-dimensional contact devices but also demonstrated enhanced efficiency in fabricating conventional 1D-contacted devices. This study addresses the demand for advanced technologies suitable for next-generation graphene devices, providing a promising and versatile graphene-patterning approach with broad applicability and high efficiency.

Nitrate reduction on bimetallic (Pd0.09Sn0.91) electrodes: Effects of calcination temperature, electrode support, and quenching

The effects of fabrication process, namely, calcination temperature, electrode support, and quenching, on electrochemical nitrate reduction were investigated, exemplified by Pd0.09Sn0.91 electrode. The electrode was characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and cyclic voltammetry. Results showed that electrode surface morphology, crystalline formation, and chemical composition, which were influenced by the electrode fabrication process, controlled nitrogen selectivity and nitrate reduction reactivity. The Pd0.09Sn0.91/SS electrodes were calcined at different temperatures (from 100 to 700 °C) for 3 h in air and the results showed that high calcination temperature rendered electrode oxidized, and decreased nitrogen selectivity and nitrate reduction capability. Electrode supports affected nitrate reduction following the order of Ni ≈SS > G > Ti. Quenching electrode in ice water decreased nitrate reduction capability. Porous surface with small oxygen content, less degree of metal oxidation (i.e., higher fraction of Pd0 and Sn0), and Sn crystals favored nitrogen selectivity and nitrate removal.

Chemoselective and Triggered Decomposition of Diazo Esters by the [(IMes)Rh2(OAc)4] Complex: En Route to Assisted Tandem Catalysis from Mixtures of Diazo Compounds

AbstractDecomposition of aryl and unsubstituted diazo ester into Rh(II)‐carbenes by the [(IMes)Rh2(OAc)4] complex is shown to be slower than with Rh2(OAc)4. Diazo esters substituted by a second electron‐withdrawing group do not suffer nitrogen extrusion when exposed for several hours to this (NHC)Rh(II) complex at room temperature. This chemoselective decomposition of diazo esters depending on their substituent (Ar, H, EWG) can furthermore be achieved on a mixture of substrates. The catalytic activity of [(IMes)Rh2(OAc)4] towards electron‐poor diazo compounds is also restored by heating to reflux in chloroform, or after decomplexation of the NHC by addition of GaCl3. The [(IMes)Rh2(OAc)4] complex was then used to induce a fully selective reaction cascade from a mixture of two diazo esters. First, a donor/acceptor diazo compound was decomposed selectively at room temperature to give an intermolecular O−H insertion product without any decomposition of the electron poor diazo compound. Addition of GaGl3 then triggered nitrogen extrusion from the diazo malonate to give a 1,5‐C−H insertion product. This transformation, where decomposition of diazo compounds catalyzed by Rh(II) complexes can be externally controlled, represents the first example of assisted tandem catalysis with two metal carbene precursors.

Breaking the inactivity of MXenes to drive Ampere-level selective oxygen evolution reaction in seawater

The limited activity and stability of conventional anodes in seawater have posed a significant obstacle to sustainable green hydrogen production directly from seawater via electrolysis. To address these challenges, we engineered Ti3C2Tx-MXene by incorporating iron and boron into its matrix (tagged FBT) for selective oxygen evolution reaction (OER). Positioning B underneath the top layer induces charge disparity on the Fe-sites, which influences the subsequent growth of the ZIF-67 metal-organic framework (MOF) on the MXene surface through Fe-O-Co ionic bonds. DFT calculations reveal a favorable binding energy of −2.30 eV at the heterointerface for ZIF-67 adsorption to the surface of FBT via O-Co bond, a shortened bond length of 1.94 Å, confirming the formation of ionic bonds. These ionic bonds tune the active sites for an enhanced and selective OER over chlorine evolution reaction (CER), preventing active Fe species' leaching and ensuring stability at >1.56 A cm−2 in 6 M alkaline seawater over 370 hours. Further, FBT and ZIF-67/FBT require low overpotentials of 521.2 and 508 mV, respectively, to deliver 1 A cm−2 in 6 M alkaline seawater. Our findings demonstrate a robust strategy to significantly expand the potential of MXenes from simple conductive substrates to efficient OER catalysts for seawater splitting and beyond.

Highly Self-Healing Co3+/Ni3+ Dual-Active Species for the Electrocatalytic Oxidation of 5-Hydroxymethylfurfural.

Electrocatalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is significant for the sustainable production of value-added chemicals. Active sites of catalysts could enhance the activity and selectivity of the HMF oxidation reaction (HMFOR), but the self-healing ability of active sites has been commonly ignored. In this work, Co(OH)2/Ni-MOF was successfully fabricated for efficient oxidation of HMF to FDCA under mild conditions. Electrochemical and cyclic stability experiments demonstrated the high self-healing properties of the dual active sites (Co3+/Ni3+). So, the retention rate of FDCA yield can still reach 98.5%, even after 90 days. HMFOR was further coupled with 4-nitrophenol hydrogenation, which promotes the yield and Faradaic efficiency of FDCA to about 100%. Therefore, this study explores the self-healing properties of species and provides new insights for designing efficient catalysts.

Au@AuPd Core-Alloyed Shell Nanoparticles for Enhanced Electrocatalytic Activity and Selectivity under Visible Light Excitation.

Plasmonic catalysis has been employed to enhance molecular transformations under visible light excitation, leveraging the localized surface plasmon resonance (LSPR) in plasmonic nanoparticles. While plasmonic catalysis has been employed for accelerating reaction rates, achieving control over the reaction selectivity has remained a challenge. In addition, the incorporation of catalytic components into traditional plasmonic-catalytic antenna-reactor nanoparticles often leads to a decrease in optical absorption. To address these issues, this study focuses on the synthesis of bimetallic core@shell Au@AuPd nanoparticles (NPs) with ultralow loadings of palladium (Pd) into gold (Au) NPs. The goal is to achieve NPs with an Au core and a dilute alloyed shell containing both Au and Pd, with a low Pd content of around 10 atom %. By employing the (photo)electrocatalytic nitrite reduction reaction (NO2RR) as a model transformation, experimental and theoretical analyses show that this design enables enhanced catalytic activity and selectivity under visible light illumination. We found that the optimized Pd distribution in the alloyed shell allowed for stronger interaction with key adsorbed species, leading to improved catalytic activity and selectivity, both under no illumination and under visible light excitation conditions. The findings provide valuable insights for the rational design of antenna-reactor plasmonic-catalytic NPs with controlled activities and selectivity under visible light irradiation, addressing critical challenges to enable sustainable molecular transformations.

Selective Synthesis of Organonitrogen Compounds via Electrochemical C-N Coupling on Atomically Dispersed Catalysts.

The C-N coupling reaction demonstrates broad application in the fabrication of a wide range of high value-added organonitrogen molecules including fertilizers (e.g., urea), chemical feedstocks (e.g., amines, amides), and biomolecules (e.g., amino acids). The electrocatalytic C-N coupling pathways from waste resources like CO2, NO3-, or NO2- under mild conditions offer sustainable alternatives to the energy-intensive thermochemical processes. However, the complex multistep reaction routes and competing side reactions lead to significant challenges regarding low yield and poor selectivity toward large-scale practical production of target molecules. Among diverse catalyst systems that have been developed for electrochemical C-N coupling reactions, the atomically dispersed catalysts with well-defined active sites provide an ideal model platform for fundamental mechanism elucidation. More importantly, the intersite synergy between the active sites permits the enhanced reaction efficiency and selectivity toward target products. In this Review, we systematically assess the dominant reaction pathways of electrocatalytic C-N coupling reactions toward various products including urea, amines, amides, amino acids, and oximes. To guide the rational design of atomically dispersed catalysts, we identify four key stages in the overall reaction process and critically discuss the corresponding catalyst design principles, namely, retaining NOx/COx reactants on the catalyst surface, regulating the evolution pathway of N-/C- intermediates, promoting C-N coupling, and facilitating final hydrogenation steps. In addition, the advanced and effective theoretical simulation and characterization technologies are discussed. Finally, a series of remaining challenges and valuable future prospects are presented to advance rational catalyst design toward selective electrocatalytic synthesis of organonitrogen molecules.

Complete dehalogenation of chloramphenicol by bimetallic alloy Pd-Au nanoparticles in a H2-Based membrane Catalyst-Film reactor

An effective treatment method to achieve complete dehalogenation of halogenated antibiotics is an urgent affair, because partially dehalogenated products remain persistent pollutants and sometimes having higher toxicity than the original antibiotics. This study is the first to achieve complete reductive dechlorination of chloramphenicol (CAP) using bimetallic alloy Pd-Au nanoparticles (Pd-AuNPs) in a hydrogen (H2)-based membrane catalyst-film reactor (H2-MCfR). Compared to mono-Pd nanoparticles (PdNPs), bimetallic alloy Pd-AuNPs gave faster removal and more complete dechlorination of CAP in batch and continuous-flow experiments. Notably, complete CAP dechlorination was achieved with a catalyst film of Pd-AuNPs (mole ratio 1:1) that had negligible catalyst loss in a 20-day continuous operation. LC-MS identified the products of reductive dechlorination, and the dominant pathways differed significantly between PdNPs and Pd-AuNPs. In particular, Pd-AuNPs favored reductive dechlorination, while PdNPs favored reduction of the –NO2 group, which led to partially dechlorinated products that were stable. Density functional theory (DFT) calculations showed how the Au atoms reduced the adsorption energy of reactants, which affected reaction selectivity. Toxicity prediction model confirmed that reducing dechlorination significantly decreased acute toxicity to fish, daphnia and green algae. Thus, the MCfR with Pd-AuNP catalysts offers promise for achieving complete dechlorination of CAP and inspires further studies for other halogenated antibiotics.

Formation of acetonitrile and ethylene from activation of ethane over cobalt-exchanged aluminosilicates: Active sites and reaction pathways

Cobalt-exchanged ZSM-5 catalyzes the ammoxidation of ethane (2 C2H6 + 3 O2 + 2 NH3 → 2 CH3CN + 6 H2O), yet the active form of cobalt, the role of the Brønsted acidic zeolite, and the reaction pathways remain elusive. Comparisons of rates and selectivities of reactions at distinctive cobalt sites (Co2+ at Al pair sites (CoZ2), Co3O4, cobalt phyllosilicate, and cobalt aluminate) suggest sites that form from CoZ2 provide the greatest rates and selectivities for CH3CN and C2H4 formation. Significantly, we revealed a large fraction of CH3CN appears to form directly through a trimolecular reaction at cobalt ions without desorption of intermediates. In parallel, a more conventional sequential pathway dehydrogenates C2H6, aminates C2H4, and oxidatively dehydrogenates C2H5NH2 to produce CH3CN. Combined rate measurements with temperature programmed reactions and in situ infrared spectra demonstrate that O2-derived intermediates at cobalt ions initiate both reaction sequences by abstracting H-atom from C2H6.

Selective Oxidation of Benzo[d]isothiazol-3(2H)-Ones Enabled by Selectfluor.

A metal-free and Selectfluor-mediated selective oxidation reaction of benzo[d]isothiazol-3(2H)-ones in aqueous media is presented. This novel strategy provides a facile, green, and efficient approach to access important benzo[d]isothiazol-3(2H)-one-1-oxides with excellent yields and high tolerance to various functional groups. Furthermore, the purification of benzoisothiazol-3-one-1-oxides does not rely on column chromatography. Moreover, the preparation of saccharine derivatives has been achieved through sequential, double oxidation reactions in a one-pot aqueous media.

Preparation of high-strength silicon carbide by SLS-RS

One major limitation of selective laser sintering (SLS) plus reaction sintering (RS) SiC ceramics was the poor mechanical properties related to those of the traditional reaction sintered SiC due to the excess residual Si and C. TiC as a new carbon source in SLS was explored in this work to improve the performance of sintered SiC. It's found that TiC could react with liquid Si and form liquid TiSi2 during the processing, and then reduce the residual Si from 26.41 vol% to 0.53 vol% in the final products. As the content of TiC increased, the flexural strength of the sintered sample increased from 274.3 MPa to 434.6 MPa. The maximum value was reached when the TiC content was 25 wt%. Continuing to add TiC would generate more TiSi2, and the flexural strength of the sintered sample would decrease.

Improving the Electrochemical Glycerol-to-Glycerate Conversion at Pd Sites via the Interfacial Hydroxyl Immigrated from Ni Sites.

The electrochemical conversion of glycerol into high-value chemicals through the selective glycerol oxidation reaction (GOR) holds importance in utilizing the surplus platform chemical component of glycerol. Nevertheless, it is still very limited in producing three-carbon chain (C3) chemicals, especially glyceric acid/glycerate, through the direct oxidation of its primary hydroxyl group. Herein, Pd microstructure electrodeposited on the Ni foam support (Pd/NF) is designed and fabricated to achieve a highly efficient GOR, exhibiting a superior current density of ca. 120 mA cm-2 at 0.8 V vs. reversible hydrogen electrode (RHE), and high selectivity of glycerate at ca. 70%. The Faradaic efficiency of C3 chemicals from GOR can still be maintained at ca. 80% after 20 continuous electrolysis runs, and the conversion rate of glycerol can reach 95% after 10-h electrolysis. It is also clarified that the dual-component interfaces constructed by the adjacent Pd and Ni sites are responsible for this highly efficient GOR. Specifically, Ni sites can effectively strengthen the generative capacity of the active adsorbed hydroxyl (OHad) species, which can steadily immigrate to the Pd sites, so that the surface adsorbed glycerol species are quickly oxidized into C3 chemicals, rather than breaking the C-C bond of glycerol; thus, neither form the C2/C1 species. This study may yield fresh perspectives on the electrocatalytic conversion of glycerol into high-value C3 chemicals, such as glyceric acid/glycerate.

The Effect of the Tetraalkylammonium Cation in the Electrochemical CO2 Reduction Reaction on Copper Electrode.

Aprotic organic solvents such as acetonitrile offer a potential solution to promote electrochemical CO2 reduction over the competing hydrogen evolution reaction. Tetraalkylammonium cations (TAA+) are widely used as supporting electrolytes in organic media due to their high solubility and conductivity. The alkyl chain length of TAA+ cations is known to influence electron transfer processes in electrochemical systems by the adsorption of TAA+, causing modifications of the double layer. In this work, we elucidate the influence of the cation chain length on the mechanism and selectivity of the CO2RR reaction under controlled dry and wet acetonitrile conditions on copper cathodes. We find that the hydrophobic hydration character of the cation, which can be tuned by the chain length, has an effect on product distribution, altering the reaction pathway. Under dry conditions, smaller cations (TEA+) preferentially promote oxalate production via dimerization of the CO2 ·- intermediate, whereas formate is favored in the presence of water via protonation reaction. Larger cations (TBA+ > TPA+ > TEA+) favor the generation of CO regardless of water content. In situ FTIR analysis showed that TBA+ cations are able to stabilize adsorbed CO more effectively than TEA+, explaining why larger cations generate a higher proportion of CO. Our findings also suggest that higher cation concentrations suppress hydrogen evolution, particularly with larger cations, highlighting the role of cation chain length size and hydrophobic hydration shell.

Identification of K+-determined reaction pathway for facilitated kinetics of CO2 electroreduction

Cations such as K+ play a key part in the CO2 electroreduction reaction, but their role in the reaction mechanism is still in debate. Here, we use a highly symmetric Ni-N4 structure to selectively probe the mechanistic influence of K+ and identify its interaction with chemisorbed CO2−. Our electrochemical kinetics study finds a shift in the rate-determining step in the presence of K+. Spectral evidence of chemisorbed CO2− from in-situ X-ray absorption spectroscopy and in-situ Raman spectroscopy pinpoints the origin of this rate-determining step shift. Grand canonical potential kinetics simulations - consistent with experimental results - further complement these findings. We thereby identify a long proposed non-covalent interaction between K+ and chemisorbed CO2−. This interaction stabilizes chemisorbed CO2− and thus switches the rate-determining step from concerted proton electron transfer to independent proton transfer. Consequently, this rate-determining step shift lowers the reaction barrier by eliminating the contribution of the electron transfer step. This K+-determined reaction pathway enables a lower energy barrier for CO2 electroreduction reaction than the competing hydrogen evolution reaction, leading to an exclusive selectivity for CO2 electroreduction reaction.

Clotrimazole Identified as a Selective UGT2B4 Inhibitor Using Canagliflozin-2'-O-Glucuronide Formation as a Selective UGT2B4 Probe Reaction.

UGT2B4 is a highly expressed drug-metabolizing enzyme in the liver contributing to the glucuronidation of several drugs. To enable quantitatively assessing UGT2B4 contribution toward metabolic clearance, a potent and selective UGT2B4 inhibitor that can be used for reaction phenotyping was sought. Initially, a canagliflozin-2'-O-glucuronyl transferase activity assay was developed in recombinant UGT2B4 and human liver microsomes (HLM) [±2% bovine serum albumin (BSA)]. Canagliflozin-2'-O-glucuronidation (C2OG) substrate concentration at half-maximal velocity value in recombinant UGT2B4 and HLM were similar. C2OG formation intrinsic clearance was five- to seven-fold higher in incubations containing 2% BSA, suggesting UGT2B4 susceptibility to the inhibitory unsaturated long-chain fatty acids released during the incubation. Monitoring for C2OG formation, 180 compounds were evaluated for UGT2B4 inhibition potency in the presence and absence of 2% BSA. Compounds that exhibited an apparent UGT2B4 IC50 of < 1 μM in HLM with 2% BSA were evaluated for inhibition of UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, UGT2B10, UGT2B15, and UGT2B17 catalytic activities to establish selectivity suitable for supporting UGT reaction phenotyping. In this study, clotrimazole was identified as a potent UGT2B4 inhibitor (HLM apparent IC50 of 11 to 35 nM ± 2% BSA). Moreover, clotrimazole exhibited selectivity for UGT2B4 inhibition (>24-fold) over the other UGT enzymes evaluated. Additionally, during this study it was discovered that the previously described UGT2B7 inhibitors 16α- and 16β-phenyllongifolol also inhibit UGT2B4. Clotrimazole, a potent and selective UGT2B4 inhibitor, will prove essential during UGT reaction phenotyping. SIGNIFICANCE STATEMENT: To mechanistically evaluate drug interactions, it is essential to understand the contribution of individual enzymes to the metabolic clearance of a drug. The present study describes the development of a UGT2B4 activity assay that enabled the discovery of the highly selective and potent UGT2B4 inhibitor clotrimazole. Clotrimazole can be used in UGT reaction phenotyping studies to estimate fractional contribution of UGT2B4.

Unraveling C–Selective Ring‐Opening of Phosphiranes with Carboxylic Acids and Other Nucleophiles: A Mechanistically‐Driven Approach

Phosphiranes are weak Lewis bases reacting with only a limited number of electrophiles to produce the corresponding phosphiranium ions. These salts are recognized for their propensity to undergo reactions with oxygen pronucleophiles at the phosphorus site, leading to the formation of phosphine oxide adducts. Building on a thorough mechanistic understanding, we have developed an unprecedented approach that enables the selective reaction of carboxylic acids, and other nucleophiles, at the carbon site of phosphiranes. This method involves the photochemical generation of highly reactive carbenes, which react with 1‐mesitylphosphirane to yield ylides. The latter undergoes a stepwise reaction with carboxylic acids, resulting in the production of the desired phosphines. In addition to DFT calculations, we have successfully isolated and fully characterized the key intermediates involved in the reaction.

Unraveling C-Selective Ring-Opening of Phosphiranes with Carboxylic Acids and Other Nucleophiles: A Mechanistically-Driven Approach.

Phosphiranes are weak Lewis bases reacting with only a limited number of electrophiles to produce the corresponding phosphiranium ions. These salts are recognized for their propensity to undergo reactions with oxygen pronucleophiles at the phosphorus site, leading to the formation of phosphine oxide adducts. Building on a thorough mechanistic understanding, we have developed an unprecedented approach that enables the selective reaction of carboxylic acids, and other nucleophiles, at the carbon site of phosphiranes. This method involves the photochemical generation of highly reactive carbenes, which react with 1-mesitylphosphirane to yield ylides. The latter undergoes a stepwise reaction with carboxylic acids, resulting in the production of the desired phosphines. In addition to DFT calculations, we have successfully isolated and fully characterized the key intermediates involved in the reaction.

Nickel‐Catalyzed Electrochemical Cross‐Electrophile C(sp2)−C(sp3) Coupling via a NiII Aryl Amido Intermediate

AbstractCross‐electrophile coupling (XEC) between aryl halides and alkyl halides is a streamlined approach for C(sp2)−C(sp3) bond construction, which is highly valuable in medicinal chemistry. Based on a key NiII aryl amido intermediate, we developed a highly selective and scalable Ni‐catalyzed electrochemical XEC reaction between (hetero)aryl halides and primary and secondary alkyl halides. Experimental and computational mechanistic studies indicate that an amine secondary ligand slows down the oxidative addition process of the Ni‐polypyridine catalyst to the aryl bromide and a NiII aryl amido intermediate is formed in situ during the reaction process. The relatively slow oxidative addition is beneficial for enhancing the selectivity of the XEC reaction. The NiII aryl amido intermediate stabilizes the NiII–aryl species to prevent the aryl–aryl homo‐coupling side reactions and acts as a catalyst to activate the alkyl bromide substrates. This electrosynthesis system provides a facile, practical, and scalable platform for the formation of (hetero)aryl–alkyl bonds using standard Ni catalysts under mild conditions. The mechanistic insights from this work could serve as a great foundation for future studies on Ni‐catalyzed cross‐couplings.

Nickel-Catalyzed Electrochemical Cross-Electrophile C(sp2)-C(sp3) Coupling via a NiII Aryl Amido Intermediate.

Cross-electrophile coupling (XEC) between aryl halides and alkyl halides is a streamlined approach for C(sp2)-C(sp3) bond construction, which is highly valuable in medicinal chemistry. Based on a key NiII aryl amido intermediate, we developed a highly selective and scalable Ni-catalyzed electrochemical XEC reaction between (hetero)aryl halides and primary and secondary alkyl halides. Experimental and computational mechanistic studies indicate that an amine secondary ligand slows down the oxidative addition process of the Ni-polypyridine catalyst to the aryl bromide and a NiII aryl amido intermediate is formed in situ during the reaction process. The relatively slow oxidative addition is beneficial for enhancing the selectivity of the XEC reaction. The NiII aryl amido intermediate stabilizes the NiII-aryl species to prevent the aryl-aryl homo-coupling side reactions and acts as a catalyst to activate the alkyl bromide substrates. This electrosynthesis system provides a facile, practical, and scalable platform for the formation of (hetero)aryl-alkyl bonds using standard Ni catalysts under mild conditions. The mechanistic insights from this work could serve as a great foundation for future studies on Ni-catalyzed cross-couplings.