Reaction Energy Barrier Research Articles

Optimizing interactions for efficient hydrogen evolution reaction by incorporating rhenium nanoparticles on defect-rich carbon

The rich anchoring site on carbon renders it a promising support for catalytically active metal nanoparticles (NPs), thereby enhancing their intrinsic catalytic activity towards hydrogen evolution reaction (HER) through interactions between the support and the metal. However, complex synthesis conditions often compromise the synergy between the metal and support. Herein, we report Re NPs embedded on XC-72 carbon support to investigate the robust interactions in affecting the HER activity. Consequently, Re NPs anchored on defect-rich XC-72 exhibit efficient and robust HER activity in acidic conditions, achieving an extremely low overpotential of 25 mV to deliver a current density of 10 mA cm−2 and a Tafel slope of 78 mV dec−1, surpassing that of Pt/C catalyst. Based on experimental investigations and density functional theory calculations, the high catalytic activities of as-obtained Re/C can be attributed to the enhanced electron transport kinetics facilitated by the interactions between Re NPs and carbon support, the exposure of the active site on Re NPs, and lowered reaction energy barrier towards HER. This study provides valuable insights for the rational development of Re-based efficient catalysts for HER.

Scalable 2D Semiconductor‐Based van der Waals Heterostructure Interface with Built‐in Electric Field for Enhanced Electrochemical Water Splitting

Electrochemical water splitting has received tremendous attention as an eco‐friendly approach to produce hydrogen. Noble metals and their oxides are commonly used as electrocatalysts to reduce activation energy barriers for hydrogen and oxygen evolution reactions in high‐performance electrodes, but their cost, scarcity, and limited stability hinder widespread adoption of electrochemical water splitting. Further advancements are therefore needed to reduce reliance on noble metals and improve the long‐term stability. Herein, solution‐processed 2D van der Waals (vdW) p–n heterostructures as an interfacial layer between catalysts and the electrode are introduced to enhance the catalytic performance. These heterostructures are formed by sequentially assembling electrochemically exfoliated black phosphorus and molybdenum disulfide nanosheets into electronic‐grade p‐ and n‐type semiconductor thin films, with the scalability extending across tens‐of‐centimeter scale areas. Benefiting from the charge distribution and built‐in electric field developed upon heterojunction formation, the vdW heterostructure interfacial layer increases both the catalytic activity and stability of commercial Pt/C and Ir/C catalysts compared to when these catalysts are directly loaded onto electrodes. Additionally, the vdW heterostructure also serves as a template for synthesizing nanostructured Pt and Ir catalysts through electrodeposition, further enhancing the catalytic performance in terms of mass activity and stability.

Substituent effects on the ESIPT process of H2O2 sensing product 1,3-bis(bispyridin-2-ylimino) isoindolin-4-ol: A theoretical study

H2O2 plays an important role in a variety of physiological processes, but its overproduction or accumulation can lead to oxidative damage and related diseases, so it is crucial to establish accurate H2O2 detection methods. Fluorescence sensing as a potential method, the design and modulation of its luminescent properties are crucial to the detection results. In this work, we investigated the sensing mechanism of a novel H2O2 fluorescent probe (P1) and examined the role of substituent effects in modulating the fluorescence properties of its reaction products. The results show that the non-fluorescence property of the probe is due to twisted intramolecular charge transfer (TICT) mechanism resulting from a torsion of the excited state molecular conformation, and the fluorescence turn-on upon recognition of H2O2 by the probe is due to the reaction product (BBYI1) following the excited state intramolecular proton transfer (ESIPT) process. When the substituent is an electron-donating group, the energy barrier of the ESIPT reaction is lowered, promoting luminescence, while the electron-withdrawing group has the opposite effect. In summary, the present work may offer a theoretical foundation for the development of more sensitive fluorescent probes for ESIPT-based H2O2 detection.

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.

Optimization of d-p band centers as efficient active sites for solar energy conversion into H2 by tuning surface atomic arrangement

The lowered reaction energy barrier and accelerated dynamic behavior for photocatalytic H2O overall splitting (HOS) involving oriented chemisorption, activation and conversion of *H and oxyhydrogen intermediates are crucial for solar energy conversion into H2 (STH). Herein, the localized heterojunction (Cd-S-Ni) composed of NiS and CdS via. tuning surface atomic arrangement with S atoms as the shared ligands has been constructed to synchronously elevate and optimize Ni 3d (Ni ε3d) and S 2p (S ε2p) band centers as efficient active sites for chemisorption of oxyhydrogen and *H intermediates with a declined Cd 4d band center (Cd ε4d) to suppress reverse reaction. A sustainable STH of 3.21 % under AM 1.5 G has been completed over Cd-S-Ni with a decreased activation energy for H2 evolution, verified by fs-TAS, in situ DRIFTS and dynamic DFT. These results devote to solving the reaction energy barrier and dynamical bottleneck for HOS by optimizing εd and εp.

Modeling Silver Corrosion Mechanisms in Marine Atmospheric Environments

Measures that can assess the severity of the local environment are an important tool for combating atmospheric corrosion. One approach for determining the environmental severity employs electrochemical analysis alongside surface characterization on silver coupons exposed to the environment for varying durations. However, despite the long use of silver as an environmental severity monitor, the underlying reaction mechanisms that give rise to the observed corrosion products are not well understood. In addition, the measured ratios of silver corrosion products appear to be unique to the location where the silver coupons were exposed.The goal of this work is to develop models of silver oxidation reactions that can explore pathways for the formation of silver corrosion products. We use density functional theory (DFT) calculations in nudged elastic band (NEB) approximations to determine electrochemical and chemical reaction along with surface diffusion energy barriers. An example reaction is shown in Figure 1a and b, in which an O2 molecule is adsorbed on an ‘on-top’ site on a relaxed Ag (100) crystal structure with periodic boundary conditions in the x and y-planes. The O2 molecule then dissociates into individual O atoms. The reaction pathway is approximated using the NEB approach to determine the dissociation energy barrier in Figure 1c. These reaction energy barriers are incorporated into a kinetic Monte Carlo (KMC) model of silver reactions to estimate the corrosion products present in marine atmospheric environments for comparison with experimental data. Figure 1

Lanthanum Transition-Metal Sulfide Electrocatalysts for Overall Water Splitting

Hydrogen has been identified as a sustainable energy source for the future with the potential of replacing fossil fuels due to its high gravimetric energy density and zero carbon emissions. Water electrolysis is a promising approach to the clean production of pure hydrogen, however, the benchmark catalysts of the half reactions of water electrolysis are noble-metal based, which limit the application of this technique.1 As well, the high energy barrier and sluggish kinetics of the oxygen evolution reaction limit the efficiency of the system. Therefore, it is crucial to develop robust, stable, and cost-effective materials for water electrolysis to be scalable. Lanthanum transition-metal oxide electrocatalysts have been pursued in the past for water splitting due to the high abundance of lanthanum and transition metals.2 However, these catalysts suffer from low conductivity and inherent instability towards oxygen evolution. Binary sulfides, selenides, and phosphides have also been pursued,3 but the compositional space of these materials is limited. Ternary sulfides offer a wider compositional space that allows fine-tuning for optimal performance. As a result, we have pursued the synthesis and application of the relatively unexplored ternary chalcogenides, LaMS3 (M = Ni, Co, Fe, Mn) towards water electrolysis. The efficiency of water electrolysis and stability of the materials have been tested with linear sweep voltammetry, galvanostatic measurements, and electrochemical impedance spectroscopy. We found these materials to be active towards both the hydrogen and oxygen evolution reactions, in acidic and alkaline conditions, respectively, with the catalysts exhibiting an activity trend where LaNiS3 > LaCoS3 > LaFeS3 > LaMnS3. For HER, LaNiS3 exhibits an overpotential of 340 mV at 10 mAcm-2 with a Tafel slope of 79 mV/decade. For OER, an overpotential of 373 mV at 10 mAcm-2 and a low Tafel slope of 48 mV/decade are observed. In addition, LaNiS3 proved to be highly stable with minimal change in potential over a period of 18 hours. The high activity and stability of LaNiS3 towards both half reactions of water electrolysis make it a promising candidate for a bifunctional water splitting electrocatalyst.References Wang, S.; Lu, A.; Zhong, C.-J. Hydrogen Production from Water Electrolysis: Role of Catalysts. Nano Convergence 2021, 8 (1), 4.Dias, J. A.; Andrade, M. A. S.; Santos, H. L. S.; Morelli, M. R.; Mascaro, L. H. Lanthanum‐Based Perovskites for Catalytic Oxygen Evolution Reaction. ChemElectroChem 2020, 7 (15), 3173–3192.Anantharaj, S.; Ede, S. R.; Sakthikumar, K.; Karthick, K.; Mishra, S.; Kundu, S. Recent Trends and Perspectives in Electrochemical Water Splitting with an Emphasis on Sulfide, Selenide, and Phosphide Catalysts of Fe, Co, and Ni: A Review. ACS Catal. 2016, 6 (12), 8069–8097.

A Stable Site‐Isolated Mono(phosphine)‐Rhodium Catalyst on a Metal‐Organic Layer for Highly Efficient Hydrogenation Reactions

AbstractPhosphine‐ligated transition metal complexes play a pivotal role in modern catalysis, but our understanding of the impact of ligand counts on the catalysis performance of the metal center is limited. Here we report the synthesis of a low‐coordinate mono(phosphine)‐Rh catalyst on a metal‐organic layer (MOL), P‐MOL • Rh, and its applications in the hydrogenation of mono‐, di‐, and tri‐substituted alkenes as well as aryl nitriles with turnover numbers (TONs) of up to 390000. Mechanistic investigations and density functional theory calculations revealed the lowering of reaction energy barriers by the low steric hindrance of site‐isolated mono(phosphine)‐Rh sites on the MOL to provide superior catalytic activity over homogeneous Rh catalysts. The MOL also prevents catalyst deactivation to enable recycle and reuse of P‐MOL • Rh in catalytic hydrogenation reactions.

Exploration of the rapid growth of high-molecular-weight oligomers in the later stage of diisocyanate self-polymerization

Diisocyanate trimers are important products in the polyurethane industry. Large amounts of high-molecular-weight oligomers, which change the physical and chemical properties of the final products, are generated in the later stages of the synthesis process. It is important to understand the self-polymerization of high-molecular-weight oligomers. The relationship between this phenomenon and the PDI monomer concentration was first experimentally demonstrated. Then the self-polymerization of pentamethylene diisocyanate (PDI) was investigated via Dmol3 calculations using the linear synchronous transition (LST) and quadratic synchronous transition (QST) methods. Calculations revealed a new synthesis pathway with a reaction energy barrier of 31.548 kcal/mol, leading to the conversion of pentamers into decamers. In the initial stage of the polymerization reaction, the PDI monomer concentration was high, and the reaction followed a step-growth polymerization. However, as the PDI monomer concentration decreased and the PDI pentamer concentration increased in the later stage of the reaction, a new synthesis pathway emerged, leading to the direct synthesis of high-molecular-weight oligomers from the available oligomers. This study further demonstrates the self-polymerization of diisocyanate and provides a comprehensive understanding of its synthesis process. By inhibiting this new pathway can reduce the content of high-molecular-weight oligomers, increase yields, and reduce the product viscosity, all of which are beneficial for chemical process optimization.

A Stable Site-Isolated Mono(phosphine)-Rhodium Catalyst on a Metal-Organic Layer for Highly Efficient Hydrogenation Reactions.

Phosphine-ligated transition metal complexes play a pivotal role in modern catalysis, but our understanding of the impact of ligand counts on the catalysis performance of the metal center is limited. Here we report the synthesis of a low-coordinate mono(phosphine)-Rh catalyst on a metal-organic layer (MOL), P-MOL • Rh, and its applications in the hydrogenation of mono-, di-, and tri-substituted alkenes as well as aryl nitriles with turnover numbers (TONs) of up to 390000. Mechanistic investigations and density functional theory calculations revealed the lowering of reaction energy barriers by the low steric hindrance of site-isolated mono(phosphine)-Rh sites on the MOL to provide superior catalytic activity over homogeneous Rh catalysts. The MOL also prevents catalyst deactivation to enable recycle and reuse of P-MOL • Rh in catalytic hydrogenation reactions.

Cluster-Level Heterostructure of PMo12/Cu for Efficient and Selective Electrocatalytic Hydrogenation of High-Concentration 5-Hydroxymethylfurfural.

Electrochemical hydrogenation of aldehyde molecules, exemplified by 5-hydroxymethylfurfural (HMF), offers a sustainable approach for synthesizing higher value-added alcohols. However, severe coupling side reactions impede its practical implementation at high concentrations. In this work, a cluster-level heterostructure of a PMo12/Cu catalyst is synthesized by loading Keggin-type phosphomolybdic acid (H3PMo12O40, PMo12) onto Cu nanowires. The catalyst exhibits high selectivity in electrocatalytic hydrogenation (ECH) of HMF to 2,5-bishydroxymethylfuran (BHMF) under an unprecedentedly high substrate concentration of 1.0 M. Under -0.3 V (vs RHE) with 1.0 M HMF, PMo12/Cu shows a Faradaic efficiency as high as 98% with an excellent productivity of 4.35 mmol cm-2 h-1 toward BHMF, much higher than those on the pristine Cu nanowires. Mechanism studies and density functional theory calculations demonstrate that the heterostructural interface of PMo12/Cu serves as an active reaction center for the ECH. The unique electronic properties and geometric structure promote the dissociative reduction of water molecules to generate H* and reduce HMF with a decreased reaction energy barrier, which is responsible for exceptional reactivity and selectivity.

Adaptive accelerated reactive molecular dynamics driven by parallel collective variables overcoming dimensionality explosion.

ReaxFF reactive molecular dynamics has significantly advanced the exploration of chemical reaction mechanisms in complex systems. However, it faces several challenges: (1) the prevalent use of excessively high temperatures (>2000K), (2) a time scale considerably shorter than the experimental timeframes (nanoseconds vs seconds), and (3) the constraining impact of dimensionality growth due to collective variables on the expansiveness of research systems. To overcome these issues, we introduced Parallel Collective Variable-Driven Adaptive Accelerated Reaction Molecular Dynamics (PCVR), which integrates metadynamics with ReaxFF. This method incorporates bond distortion based on each bond type for customized Collective Variable (CV) parameterization, facilitating independent parallel acceleration. Simultaneously, the sampling was confined to fixed cutoff ranges for distinct bond distortions, effectively overcoming the challenge of the CV dimensionality explosion. This extension enhances the applicability of ReaxFF to non-strongly coupled systems with numerous reaction energy barriers and mitigates the system size limitations. Using accelerated reactive molecular dynamics, the oxidation of ester-based oil was simulated with 31 808 atoms at 500K for 64s. This achieved 61% efficiency compared to the original ReaxFF and was ∼37 times faster than previous methods. Unlike ReaxFF's high-temperature constraints, PCVR accurately reveals the pivotal role of oxygen in ester oxidation at industrial temperatures, producing polymers consistent with the sludge formation observed in ester degradation experiments. This method promises to advance reactive molecular dynamics by enabling simulations at lower temperatures, extending to second-level timescales, and accommodating systems with millions of atoms.

Steering the Site Distance of Atomic Cu-Cu Pairs by First-Shell Halogen Coordination Boosts CO2-to-C2 Selectivity.

Electrocatalytic reduction of CO2 into C2 products of high economic value provides a promising strategy to realize resourceful CO2 utilization. Rational design and construct dual sites to realize the CO protonation and C-C coupling to unravel their structure-performance correlation is of great significance in catalysing electrochemical CO2 reduction reactions. Herein, Cu-Cu dual sites with different site distance coordinated by halogen at the first-shell are constructed and shows a higher intramolecular electron redispersion and coordination symmetry configurations. The long-range Cu-Cu (Cu-I-Cu) dual sites show an enhanced Faraday efficiency of C2 products, up to 74.1 %, and excellent stability. In addition, the linear relationships that the long-range Cu-Cu dual sites are accelerated to C2H4 generation and short-range Cu-Cu (Cu-Cl-Cu) dual sites are beneficial for C2H5OH formation are disclosed. In situ electrochemical attenuated total reflection surface enhanced infrared absorption spectroscopy, in situ Raman and theoretical calculations manifest that long-range Cu-Cu dual sites can weaken reaction energy barriers of CO hydrogenation and C-C coupling, as well as accelerating deoxygenation of *CH2CHO. This study uncovers the exploitation of site-distance-dependent electrochemical properties to steer the CO2 reduction pathway, as well as a potential generic tactic to target C2 synthesis by constructing the desired Cu-Cu dual sites.

Theoretical study on the effect of different positions of -CN group on photophysical properties and forward-reverse ESIPT behaviours of 2,5-bis(benzo[d]thiazol-2-yl)phenol derivatives

Excited state intramolecular proton transfer (ESIPT) compounds have been widely used in many fields due to its unique photophysical properties, but they are strongly affected by substituents. There are many studies on the effect of substituents at the same position on the ESIPT process, but there are few studies on the effects of substituents at different positions on the proton transfer process. In this work, a strong electron-withdrawing cyano group ( – CN) was introduced into different positions of 2,5-bis(benzo[d]thiazol-2-yl)phenol. The effect of different substituted positions on intramolecular hydrogen bond (IHB), photophysical properties and forward-reverse energy barrier of ESIPT reaction have been systematically investigated adopting density functional theory (DFT) and time-dependent DFT. The result showed that the introduction of – CN group at different positions led to a slight red-shift of absorption, and intramolecular charger transfer is the intrinsic reason for this photophysical phenomenon. The position of – CN group obviously influenced the excited state IHB, and then had an effect on ESIPT process. The substitution positions in the left benzo[d]thiazole ring and phenol ring respectively hinder and promote the ESIPT process, while the substitution in the right benzo[d]thiazole ring not only impetus the ESIPT process, but also increase the tautomer fluorescence.

Engineering rich defects in nitrogen-doped porous carbon to boost oxygen reduction reaction kinetics

Metal-free carbon-based materials offer a promising alternative to Pt-based catalysts for the oxygen reduction reaction (ORR). However, challenges persist due to its sluggish kinetics and poor acid ORR performance. Here, we introduce a novel nitrogen-doped porous carbon with rich defects sites (such as pentagons, edge and vacancy defects) (PV/HPC) via a simple etching strategy. The PV/HPC demonstrates long-term stability and exceptional catalytic activity with half-wave potential of 0.9 V and average electron transfer number of 3.98 in alkaline solution while 0.78 V and 3.78 in acidic solution, indicating its efficiency and robustness as an ORR catalyst. Additionally, it achieves a higher kinetic current density of 91.9 mA cm−2 at 0.8 V, which is 1.75 times that of Pt/C (52.5 mA cm−2). Furthemore, it enables Al-air battery to attain a maximum power density of 487 mW cm−2, compared to 477 mW cm−2 for the Pt/C catalyst. Density functional theory (DFT) calculations elucidate that the introduction of multifunctional defects in nitrogen-doped porous carbon collectively reduces the reaction energy barrier of the departure of OH* and boosts the oxygen reduction reaction kinetics. This work presents a simple method to design durable and effective carbon-based ORR catalysts.

Heterostructure Fe7S8/Mn(OH)2 of incomplete sulfurization induces Mn atoms with high density of states for enhancing oxygen evolution reaction and supercapacitor electrochemical performance

Heterostructures and the introduction of heterogeneous elements have been regarded as effective strategies to promote electrochemical performance. Herein, sulfur species are introduced by a simple hydrothermal vulcanization method, which constructs the open heterostructure Fe7S8/Mn(OH)2 as a bifunctional material. The open cordyceps-like morphology can make the material contact more sufficiently with the electrolyte, exposing a large number of reaction sites. Furthermore, the introduction of the heterogeneous element S successfully constructs a heterogeneous interface, the interface-modulated composite material consists of Mn atoms contributing the main density of states (DOS) near the Fermi energy level from the density functional theory (DFT) calculations, which optimizes the adsorption energy of oxygen-containing intermediates during the oxygen evolution reaction (OER) process and reduces the reaction energy barrier, being conducive to the improvement of the material’s electrochemical properties. As predicted, the Fe7S8/Mn(OH)2 material exhibits remarkable electrochemical properties, such as an overpotential of 202 mV at 10 mA cm−2 for the oxygen evolution reaction and even a specific capacitance of 2198 F g−1 at 1 A g−1. This work provides new insights into the role of introducing sulfur species and controlling the structure of the material, and exemplifies novel design ideas for developing bifunctional materials for energy storage and conversion.

Fenton chemistry activation in metal-organic frameworks for synergistic bacteria eradication

The development of novel antibacterial strategies as alternatives to antibiotics is of great significance but remains considerable challenges due to the lack of safe, effective, and broad-spectrum agents. Here, we explored the potential of a biocompatible metal–organic framework Fe-MIL-53-NH2 (FM) for reactive oxygen species (ROS)-based antibacterial applications. However, FM was found to be catalytically inert due to the very weak reducibility of Fe3+ toward H2O2. To address this challenge, we incorporated a small amount of Co2+ (0.98 %) into FM (CFM), successfully activating Fenton chemistry and achieving a notable 5.5-fold improvement in Fenton activity. Density functional theory (DFT) calculations revealed that a very small amount of Co2+ doping significantly reduces the energy barrier of the Fenton reaction by shifting the d-band center to the Fermi level and optimizing the charge density of active Co atoms. We further enhanced the antibacterial properties of CFM by modifying it with the photothermal agent polydopamine (PDA), resulting in CFMP. Through the synergistic effects of ROS and photothermal properties, CFMP exhibited remarkable antibacterial activity, with bacterial eradication rates exceeding 99 % against both E. coli and S. aureus. Moreover, in vivo experiments demonstrated the exceptional efficacy of CFMP in sterilizing S. aureus-infected wounds, while causing negligible damage to other major organs. This study not only highlights the role of atom engineering in activating Fenton reaction, but also provides rational designs for a synergistic antibacterial strategy via powerful MOFs chemistry.

Mechanistic Insights into N2O5-Halide Ions Chemistry at the Air-Water Interface.

The activation of halogens (X = Cl, Br, I) by N2O5 is linked to NOx sources, ozone concentrations, NO3 reactivity, and the chemistry of halide-containing aerosol particles. However, a detailed chemical mechanism is still lacking. Herein, we explored the chemistry of the N2O5···X- systems at the air-water interface. Two different reaction pathways were identified for the reaction of N2O5 with X- at the air-water interface: the formation of XNO2 or XONO, along with NO3-. In the case of the Cl- system, the ClNO2 generation pathway is more favorable, while for the Br- and I- systems, the formation of BrONO and IONO is barrierless, making them the predominant products. Furthermore, the mechanisms of formation of X2 from XNO2 and XONO were also investigated. The high energy barriers of reactions and the high free energies of the products compared to those of the reactants indicate that ClNO2 is stable at the air-water interface. Contrary to the widely held belief regarding X2 producing from the reaction of XNO2 with X-, our calculations demonstrate that BrONO and IONO initially form stable BrONO···Br- and IONO···I- complexes, which then subsequently react with Br- and I- to form Br3- and I3-, respectively. Finally, Br3- and I3- decompose to form Br2 and I2. These findings have significant implications for experimental interpretation and offer new insights into halogen cycling in the atmosphere.

Selective Activation of Lattice Oxygen Site Through Coordination Engineering to Boost the Activity and Stability of Oxygen Evolution Reaction.

Although Ru-based materials are among the outstanding catalysts for the oxygen evolution reaction (OER), the instability issue still haunts them and impedes the widespread application. The instability of Ru-based OER catalysts is generally ascribed to the formation of soluble species through the over-oxidation of Ru and structural decomposition caused by involvement of lattice oxygen. Herein, an effective strategy of selectively activating the lattice oxygen around Ru site is proposed to improve the OER activity and stability. Our synthesized spinel-type electrocatalyst of Ru and Zn co-doped Co3O4 showed an ultralow overpotential of 172 mV at 10 mA cm-2 and a long-term stability reaching to 100 hours at 10 mA cm-2 for alkaline OER. The experimental results and theoretical simulations demonstrated that the lattice oxygen site jointly connected with the octahedral Ru and tetrahedral Zn atoms became more active than other oxygen sites near Ru atom, which further lowered the reaction energy barriers and avoided generating excessive oxygen vacancies to enhance the structural stability of Ru sites. The findings hope to provide a new perspective to improve the catalytic activity of Ru-incorporated OER catalysts and the stability of lattice-oxygen-mediated mechanism.

Selective Activation of Lattice Oxygen Site Through Coordination Engineering to Boost the Activity and Stability of Oxygen Evolution Reaction

AbstractAlthough Ru‐based materials are among the outstanding catalysts for the oxygen evolution reaction (OER), the instability issue still haunts them and impedes the widespread application. The instability of Ru‐based OER catalysts is generally ascribed to the formation of soluble species through the over‐oxidation of Ru and structural decomposition caused by involvement of lattice oxygen. Herein, an effective strategy of selectively activating the lattice oxygen around Ru site is proposed to improve the OER activity and stability. Our synthesized spinel‐type electrocatalyst of Ru and Zn co‐doped Co3O4 showed an ultralow overpotential of 172 mV at 10 mA cm−2 and a long‐term stability reaching to 100 hours at 10 mA cm−2 for alkaline OER. The experimental results and theoretical simulations demonstrated that the lattice oxygen site jointly connected with the octahedral Ru and tetrahedral Zn atoms became more active than other oxygen sites near Ru atom, which further lowered the reaction energy barriers and avoided generating excessive oxygen vacancies to enhance the structural stability of Ru sites. The findings hope to provide a new perspective to improve the catalytic activity of Ru‐incorporated OER catalysts and the stability of lattice‐oxygen‐mediated mechanism.