The electrochemical reduction of CO to acetate on Cu-based catalysts is constrained by a kinetic trade-off between CO activation and the availability of active hydrogen (*H) species. Herein, we overcome this limitation by constructing a synergistic catalyst comprising Cu nanoparticles and Cu single atoms (CuNP-Cu1), which leverages a hydrogen spillover mechanism. The Cu1 sites facilitate water dissociation to generate *H, which subsequently spills over to adjacent Cu NPs, enabling efficient hydrogenation of the *OCCO intermediate, with subsequent formation of *CCO selectively. This synergy delivers an acetate faradaic efficiency of 60.6% with an acetate partial current density of 111.1 mA cm-2 and stable operation for 132 h. Operando spectroscopy measurements and theoretical calculations collectively reveal that the Cu1-mediated hydrogen spillover shifts the reaction pathway toward acetate formation. This work establishes hydrogen spillover as a design principle for coordinating multistep reactions in CO electroreduction.

Beyond catalyst design, electrolyte effects provide an alternative to improve acidic CO2 electroreduction reaction (CO2RR) performance, yet the underlying mechanisms, especially dynamic interfacial behaviors of reactive species, remain unclear. Here we tailor the interfacial microenvironment of an Fe-N-C model catalyst for acidic CO2RR by tuning pH and concentration of a K2SO4 electrolyte, with a CO Faradaic efficiency of 95.7% and a maximum CO partial current density of 103.9 mA cm-2 in 0.6 M K2SO4 with pH 2. Finite element simulations indicate that a delicate balance between the alkaline interfacial microenvironment and acidic bulk electrolyte is favorable for inhibiting HER while maintaining sufficient CO2 availability. In situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) measurements and ab initio molecular dynamics (AIMD) simulations reveal that both pH and cation can reorganize the hydrogen-bond network of interfacial water and thus facilitate CO2 accessibility and adsorption over Fe sites, resulting in improved CO selectivity in acidic media.

Cr element doping was studied to regulate the density of exsolved FeNi nanoparticles in Sr 2 Fe 1.1 Ni 0.2 Cr 0.2 Mo 0.5 O 6− δ perovskite and improve its CO 2 electrolysis activity.

Metal exsolution in perovskite oxides has emerged as an effective way to boost CO2 electrolysis activity in solid oxide electrolysis cells (SOECs). It is crucial to precisely tailor the exsolution characteristics to optimize the catalytic functionality and boost the catalytic activity. Herein, we reveal that Cr cation doping effectively modifies the crystal defects and regulates the metal exsolution of Sr2Fe1.1Ni0.2Cr0.2Mo0.5O6-delta (SFNCM). FeNi alloy nanoparticles with an average particle size of similar to 10 nm and a particle density exceeding 1500 mu m-2 were exsolved on the surface of SFNCM perovskite, which increases the active sites and enhances CO2 electrolytic activity. The SFNCM-based SOEC decorated with abundant FeNi alloy nanoparticles achieves a high current density of 2.57 A cm-2 at 1.6 V, superior to other Sr2Fe1.3Ni0.2Mo0.5O6-delta counterparts. The experimental and theoretical calculation results demonstrate the controllability of the exsolution via engineering of the perovskite structural feature. This work offers a new perspective on the lattice doping strategy for the regulation of metal exsolution.

Selective oxidative coupling of methane is fundamentally constrained by the lack of controllable oxygen species for C-H bond activation. Here, we show that electrochemical spillover oxygen species on the Au anode surface in solid oxide electrolysis cells could effectively dictate the CH4 activation pathways. In situ spectroscopy combined with theoretical analysis reveals that anodic polarization produces two oxygen species with distinct reactivity. Under anodic polarization, CH4 activation proceeds predominantly via a methyl radical-mediated pathway, as directly evidenced by synchrotronic photoionization mass spectrometry, thereby enabling selective gaseous C-C coupling. This study deepens the understanding of the nature of electrochemical spillover oxygen while establishing a mechanistic framework for electrochemical modulation of oxygen states to steer selective CH4 oxidation.

Renewable energy-driven electrosynthesis of ethylene oxide (EO) from ethylene is highly desired, as it is a low-carbon alternative to current industrial production process. The direct electrocatalytic ethylene epoxidation with water as a green oxidant is promising, yet it suffers from the activity-selectivity trade-off due to uncontrolled overoxidation. Here we construct PdO supported Pt single atoms to generate superoxo species as reactive oxygen species (ROS) and accelerate selective oxidation of ethylene. This catalyst design enables efficient EO production in a zero-gap membrane electrode assembly electrolyzer, with a partial current density of 71 mA cm-2 at a low cell voltage of 2.6 V. Furthermore, a scale-up demonstration using a 100 cm2 electrolyzer achieves a remarkable EO production rate of 6.4 g h-1 at a total current of 15 A. Thorough in situ spectroscopic characterizations and theoretical calculations indicate that the Pt single atoms, in synergy with ClO4- anions present in electrolyte, enable facile generation of abundant superoxo species and accelerated epoxidation of ethylene that is activated by the PdO support. This work highlights the importance of generating and stabilizing specific ROS for selective oxidation of organic molecules.

1,4-Butanediol (1,4-BDO) is an important chemical with growing interest due to its use in biodegradable polymers. Its conventional synthesis by the Reppe process involves the condensation of acetylene and formaldehyde, followed by hydrogenation, demanding multiple steps and stringent safety/environmental regulation. In this work, we demonstrated the electrosynthesis of 1,4-BDO from ethylene and water by coupling the reductive coupling of 2-bromoethanol (2-Br-EtOH) with the Br- redox. The homocoupling of 2-Br-EtOH into 1,4-BDO was the limiting reaction. By a data-mining-assisted approach, we identified N-based ligands with an -NH2 group and appropriate Fukui functions as promoters for 1,4-BDO formation on Cu electrodes. The optimal 2-aminoimidazole ligand could generate 55.1% yield and 61.4% selectivity of 1,4-BDO from 2-Br-EtOH, by facilitating surface Cu+ formation for homocoupling, suppressing adsorbed hydrogen formation for hydrogenation, and retarding electron injection to create a local pH gradient toward the non-Faradaic production of ethylene oxide. By integrating the anode with hydrophobic carbon for Br- oxidation and its sequential reaction with gaseous ethylene into 2-Br-EtOH, we demonstrated the 1,4-BDO electrosynthesis under internal 2-Br-EtOH and Br- cycling, with ethanol as the only side product. This work extends the industrial synthetic strategy toward 1,4-BDO to a safe and green electrocatalytic route using low-cost ethylene and water as raw materials.

Oxide supports are well known to significantly influence the structure and properties of active oxide overlayers through strong oxide-support interactions. However, the effect of oxide overlayers on the underlying active oxide substrates remains poorly understood. Here, we report the controllable formation of ceria (CeO2) overlayers on a hematite (Fe2O3) surface (CeO2/Fe2O3) via a melting-wetting method. Submonolayer CeO2 patches facilitate the partial reduction of surrounding Fe2O3 to active magnetite (Fe3O4) while effectively suppress further reduction of Fe3O4 to inactive metallic iron (Fe-0) under harsh high-temperature water-gas shift (HT-WGS) conditions. We demonstrate this stabilization effect of surface oxide patches (MOx, M = Ce, Cr, Mn, Mg, Al and Zn) on surrounding active Fe oxide sites via creating a shielding zone around each oxide patch. As a result, Fe2O3 catalysts covered with a small amount of CeO2 surface overlayers (similar to 1.8 wt%) exhibit remarkable stability at 450 degrees C for over 100 h, in contrast to rapid deactivation observed in pure Fe2O3 and industrial iron-chromium (6.5 wt% Cr) catalysts. Building on these findings, we have developed an advanced HT-WGS process that utilizes Cr-free catalysts and significantly reduces steam consumption. This study highlights the critical role of surface oxide overlayers in modulating the redox behavior and reactivity of underlying active oxide substrates, developing an interface confinement strategy for the design of robust and efficient oxide catalysts. (c) 2026, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Salt precipitation and carbon loss caused by carbonate formation and crossover limit the industrial scalability of CO2 electrolysis using alkaline or pH-neutral electrolytes. Here we constructed an alkaline polymer layer-coated proton-exchange-membrane electrolyzer to suppress CO2 crossover and prevent salt precipitation by pure water feeding. Guided by finite element simulations, alkaline polymers with a high density of quaternary ammonium groups were synthesized to enrich OH- and modulate the electric field within the catalyst electric double layer, thereby enhancing CO2 adsorption and interfacial ionic conductivity. Consequently, the electrolyzer achieved a single-pass CO2 conversion of 62.4%, energy efficiency of 39.0% and similar to 80% CO2 utilization, with stable operation for 260 h at 200 mA cm(-2). In addition, a scaled-up electrolyzer stack comprising 6 x 100 cm(2) membrane electrode assemblies produced CO at a maximum rate of 2,054.5 ml min(-1) at 70 A.

The complex structural evolution of oxide catalysts during CO2 hydrogenation presents both challenges and opportunities for optimizing catalytic performance. This study demonstrates reaction-induced transformation of In2O3 particles into InOx nanolayers and subsurface In-Zr-O solid solutions on ZrO2 (denoted as In-ZrO2@InOx), significantly enhancing methanol synthesis efficiency. Under CO2/H2 reaction conditions, mobile metallic In0 generated from H2 reduction drives redispersion of In2O3 into surface InOx nanolayers, while subsequent inter-diffusion between In0 and Zr(CO3)2 leads to the formation of subsurface In-Zr-O solid solutions. Through precise control of temperature, pressure, and gas composition, we achieve optimal distribution of three distinct In species: In2O3 nanoparticles, surface InOx nanolayers, and subsurface In-Zr-O solid solutions. The engineered In-ZrO2@InOx catalyst exhibits a methanol space-time yield of 1.1 gmethanol/gcat/h with remarkable stability over 600 hours at 300 °C. Our findings highlight the crucial role of both surface and subsurface oxide species in oxide-catalyzed reactions and demonstrate the effectiveness of reaction-driven restructuring strategies for catalyst optimization.

Urea electrosynthesis from carbon dioxide (CO2) and nitrate under mild conditions offers a sustainable alternative to existing industrial urea production route. Yet, the crucial electrocatalytic C–N coupling step strongly competes with parallel CO2 reduction and nitrate reduction pathways, leading to a challenging activity-selectivity trade-off for efficient urea electrosynthesis. Here we develop a single atom In-modified CuO (In1-CuO) catalyst with well-defined dual active sites for the co-reduction of CO2 and nitrate. Electrochemical characterizations and density functional theory calculations indicate that the single In sites and surrounding Cu sites are favorable for the co-adsorption of the *NO and *CO intermediates and synergistically accelerates subsequent C–N coupling step. Consequently, the In1-CuO catalyst shows very promising performance for urea electrosynthesis from CO2 and nitrate, with a high urea Faradaic efficiency of 68.6% at 100 mA cm−2 and a maximum formation rate of 4.6 g h−1 gcat−1. This work provides new guidelines for rationally designing highly efficient catalytic materials with dual active sites for coupling reactions.

Discovering next-generation heterogeneous catalysts calls for embracing the full complexity of active site formation under realistic conditions. Here, we develop a robust machine learning potential (MLP)-aided computational framework that integrates realistic preparation and reaction conditions to effectively track the formation of active sites and decipher structure-activity relationships. Using syngas conversion over the ZnxCryOz system as a demonstration, we identified that the system preferentially segregates into ZnO and ZnCr2O4 phases, with ZnO forming a monolayer on ZnCr2O4 surfaces under preparation conditions. Under reaction conditions, by deploying CH─O bond dissociation as a descriptor, we found that the ZnO/ZnCr2O4(100) surface is the active surface. Crucially, we pinpoint geometrically linked oxygen vacancy pairs as the true active sites. Full microkinetic analyses conducted on these active sites yield kinetic results that align well with experimental observations. Beyond elucidating the active structure, a model for designing oxide/oxide catalysts to achieve high activity is generalized, opening new pathways for accelerating catalyst discovery across a wide range of reactions.

The evolution of metal oxides, a cornerstone class in heterogeneous catalysis, has progressed from bulk materials to low-dimensional structures designed to maximize active site exposure. Among them, two-dimensional (2D) metal oxide nanolayers supported on metal or oxide surfaces are particularly distinctive, as their unique geometric and electronic structures endow them with enhanced activity and controllable selectivity in catalytic reactions. Their properties are further shaped by the interface with the substrate, which can induce unusual structural characteristics such as non-stoichiometry, metastable state, structural flexibility, and charge redistribution. While extensive research has elucidated the role of the oxide-metal interface in modulating catalytic behavior, the mechanistic understanding of the oxide-oxide interface still lags far behind that of the oxide-metal interface.In this Account, we begin by outlining the construction of 2D metal oxide nanolayers with lessons learned from oxide-metal systems extending to oxide-oxide systems, while highlighting innovative construction approaches we have recently developed, including melting-wetting, reduction-wetting, and reduction-evaporation-anchoring methods. We then delve into the fundamental characteristics of metal oxide nanolayers on oxide substrate, namely, their self-limited two-dimensionality, unsaturated coordination, and metastable nature and how these properties are linked to their enhanced catalytic performance. The central objective of this Account is to establish a unified conceptual framework for the "interface confinement effect", demonstrating its broad applicability from oxide-metal to emergent oxide-oxide systems and the unique confinement effect in the oxide-oxide systems. We reveal that this universal effect originates from a shared fundamental principle: the metal-metal (M-M ') bonding at the oxide-metal interface finds its counterpart in the metal-oxygen-metal (M-O-M ') bonding at the oxide-oxide interface. A quantitative understanding of this underexplored effect in oxide-oxide systems is achieved through a structural descriptor that leverages the nature of surface oxygen on the oxide substrate. Finally, we outline the key challenges and opportunities in this emerging field, particularly the dynamic confinement effect, including the pushing effect from the reaction and the pulling effect from the interfacial microenvironment, and its implications for rational catalyst design.

Acidic CO2 electrolysis offers great potential for high-efficiency single-pass CO2 conversion to valuable fuels and chemicals, yet is challenged by the kinetically favorable hydrogen evolution reaction. Electrode coatings can engineer a favorable electrode-electrolyte interface by regulating interfacial ion flux to steer the reaction pathway toward CO2 electroreduction; however, rational design rules for such coatings remain elusive. Here, we decouple the roles of binders and inorganic fillers in the coatings and demonstrate that coupling a cation-exchange ionomer (CEI) with a proton-blocking oxide yields a durable coating that enables efficient acidic CO2 electrolysis. Combined experimental and simulation results reveal that this optimal formulation promotes inward K+ transport while restricting H+ influx and outward OH- transport, thereby establishing a K+-enriched and alkaline interfacial microenvironment that enhances CO2/CO adsorption and lowers the *CO dimerization barrier. As a representative demonstration, an Al2O3/CEI-coated Cu electrode achieves a maximum Faradaic efficiency (FE) of 81.3% for multi-carbon (C2+) products at 600 mA cm-2 and remarkably durable operation for 200 h at 200 mA cm-2. Furthermore, this proposed electrode coating strategy demonstrates the broad generality in engineering interfacial microenvironments across distinct catalyst platforms.

Bicarbonate electrolysis coupling upstream CO 2 capture with electrochemical conversion of captured CO 2 presents an energy‐efficient alternative to existing CO 2 electrolysis route. Yet, its practical application is impeded by unsatisfactory reaction rate and energy efficiency. Here, we have improved the bicarbonate electrolysis performance through manipulating reaction microenvironments by introducing ionomers into cobalt phthalocyanine (CoPc) electrodes. The Nafion‐incorporated CoPc electrode exhibits a maximum CO partial current density of 410 mA cm −2 at a low cell voltage of 3.09 V in a cation exchange membrane‐based zero‐gap electrolyzer. Electrode structure characterization and finite element simulation results indicate that the proton conductivity of the Nafion ionomer increases the local concentration of in situ generated CO 2 around CoPc catalyst, resulting in impressive CO production performance. A closed‐loop demonstration using the Nafion‐incorporated CoPc electrode and a simulated flue gas underscores the great promise of the bicarbonate‐mediated integrated CO 2 capture and electrolysis process.

Single-atom catalysts (SACs) offer high atomic efficiency and catalytic activity but are prone to aggregation and degradation under high-temperature conditions. Here, we propose a thermally and electrochemically stable high-valent iridium single atom synthesis strategy based on strong metal-support interactions (SMSI) to enhance high-temperature CO2 electrolysis performance in solid oxide electrolysis cells (SOECs). The SMSI effect, in situ induced during high-temperature cell fabrication and operation, stabilizes the high-valent iridium single atom and simultaneously modulates the surface electronic structure of the La0.6Sr0.4FeO3-δ (LSF) cathode by weakening the Fe-O hybridization, finally promoting oxygen vacancy formation and enhancing CO2 adsorption and activation. This approach boosts the CO2-to-CO electrolysis current density by 80.8% relative to the pristine LSF cathode, achieving 3.02 A cm-2 at 800°C and 1.5 V with nearly 100% Faradaic efficiency and excellent stability over 600 h. These findings provide a viable strategy for designing thermally and electrochemically robust SACs for high-temperature catalytic reactions.

Abstract Electrochemical reduction of nitric oxide (NO) to ammonia (NH3) offers a more sustainable pathway. However, significant challenges remain in achieving high NH3 Faradaic efficiency, industrially relevant production rates, and downstream purification to meet commercial standards. Here, we report a cobalt–copper single-atom alloy (CoCu SAA) catalyst that has a remarkable NH3 production rate of 8995.9 μmol cm–2 h–1 in a flow cell and a current density of 1338.3 mA cm–2 with an NH3 Faradaic efficiency of 90.0%. Furthermore, the membrane electrode assembly (MEA) electrolyzer delivered an NH3 Faradaic efficiency of 91.8% at a current density of 3.0 A cm–2 and a cell voltage of 2.21 V. Electrochemical spectroscopic characterizations and density functional theory calculations reveal that isolated Co dopants optimize the adsorption strength of *NO and key reaction intermediates by modulating the electronic structure of neighboring Cu atoms, thus decreasing the energy barrier for the reaction and enhancing the catalytic activity and selectivity of NO electroreduction.

Dendrites are ubiquitous in nature and, despite their simple architecture, serve critical roles. In batteries, dendrite formation is a key source of safety hazards, whereas in biological systems, dendrites constitute...

Electrochemical reduction of acetylene (C2H2) to ethylene (C2H4) presents a promising pathway for sustainable energy storage. However, practical application is constrained by low current density and limited product yield, primarily due to competitive side reactions, including hydrogen evolution, C2H4 overhydrogenation, and C–C coupling. Herein, the CuAg2 catalyst achieves a Faradaic efficiency of 94.3% for C2H4 and a record current density of 3 A cm−2 in an alkaline membrane electrode assembly electrolyzer at 2.64 V, corresponding to a single-pass C2H2 conversion of 65.7%. Raman spectroscopy and theoretical calculation results reveal that the silver (Ag) site not only modulates the adsorption configuration of C2H2 but also promotes the formation and migration of active hydrogen (∗H) species. The scale-up demonstration with a 15 × 100 cm2 electrolyzer stack achieved a peak C2H4 formation rate of 21.63 L min−1 at 250 A. Furthermore, comprehensive life cycle assessments provide compelling evidence supporting the economic viability and sustainability of the electrochemical C2H2-to-C2H4 reduction process.