Reaction Energy Research Articles

Enhanced dynamics of Al3+/H+ ions in aqueous aluminum ion batteries: Construction of metastable structures in vanadium pentoxide upon oxygen vacancies

In recent years, aqueous aluminum ion batteries have been widely studied owing to their abundant energy storage and high theoretical capacity. An in-depth study of vanadium oxide materials is necessary to address the precipitation of insoluble products covered cathode surface and the slow reaction kinetics. Therefore, a method using a simple one-step hydrothermal preparation and oxalic acid to regulate oxygen vacancies has been reported. A high starting capacity (400 mAh g−1) can be achieved by Ov-V2O5, and it is capable of undergoing 200 cycles at 0.4 A g−1, with a termination discharge capacity of 103 mAh g−1. Mechanism analysis demonstrated that metastable structures (AlxV2O5 and HxV2O5) were constructed through the insertion of Al3+/H+ during discharging, which existed in the lattice intercalation with V2O5. The incorporation of oxygen vacancies lowers the reaction energy barrier while improving the ion transport efficiency. In addition, the metastable structure allows the electrostatic interaction between Al3+ and the main backbone to establish protection and optimize the transport channel. In parallel, this work exploits ex-situ characterization and DFT to obtain a profound insight into the instrumental effect of oxygen vacancies in the construction of metastable structures during in-situ electrochemical activation, with a view to better understanding the mechanism of the synergistic participation of Al3+ and H+ in the reaction. This work not only reports a method for cathode materials to modulate oxygen vacancies, but also lays the foundation for a deeper understanding of the metastable structure of vanadium oxides.

Tailoring the d-Band Center of WS2 by Metal and Nonmetal Dual-Doping for Enhanced Electrocatalytic Nitrogen Reduction.

Tuning the adsorption energy of nitrogen intermediates and lowering the reaction energy barrier is essential to accelerate the kinetics of nitrogen reduction reaction (NRR), yet remains a great challenge. Herein, the electronic structure of WS2 is tailored based on a metal and nonmetal dual-doping strategy (denoted Fe, F-WS2) to lower the d-band center of W in order to optimize the adsorption of nitrogen intermediates. The obtained Fe, F-WS2 nanosheet catalyst presents a high Faradic efficiency (FE) of 22.42% with a NH3 yield rate of 91.46µg h-1 mgcat. -1. The in situ characterizations and DFT simulations consistently show the enhanced activity is attributed to the downshift of the d-band center, which contributes to the rate-determining step of the second protonation to form N2H2 * key intermediates, thereby boosting the overall nitrogen electrocatalysis reaction kinetics. This work opens a new avenue to enhanced electrocatalysis by modulating the electronic structure and surrounding microenvironment of the catalytic metal centers.

Development of technology for obtaining flameless energy sources

The article discusses the many advantages of obtaining a flameless heating mixture based on magnesium powder and sodium hydroxide and the technology for obtaining sources of flameless energy resulted from an exothermic reaction between magnesium chloride and sodium hydroxide. The aim is to obtain flameless heaters based on a mixture of magnesium powder. First, the effective amount of a flameless heating mixture was determined, and secondly, the amount of reaction energy of the heating mixture, that is, a mixture of reagents with water, and the degree of their acidity.

Bi3TiNbO9/Bi2S3 Heterojunction for Efficient Photosynthesis of H2O2 in Pure Water

AbstractHeterojunction engineering has been deemed one of the most promising strategies for promoting charge separation and improving solar‐to‐chemicals efficiency. Howbeit, constructing well‐defined nanoheterojunction with superior photocatalytic activity for H2O2 generation and a clear reaction mechanism remains a formidable challenge. Herein, an in situ vulcanization way to synthesize an intriguing 2D/1D Bi3TiNbO9/Bi2S3 heterojunction by growing Bi2S3 nanorods on Bi3TiNbO9 microsheet is used for the first time, where an S‐scheme charge transfer mechanism is formed that facilitates the spatial separation of charge carriers. Moreover, the in situ grown Bi2S3 on Bi3TiNbO9 can optimize the interfacial electronic structure and the reaction energy barriers. As a result, the H2O2 yield rate for Bi3TiNbO9/Bi2S3 can reach 810(2) µmol g−1 h−1 without any sacrificial agents and cocatalysts, ≈6.18 and ≈18.0 times of pristine Bi3TiNbO9 and Bi2S3, respectively. Importantly, the heterojunction unveiled unprecedented stability, remaining ≈95.46(2)% of the initial one after 13 continuous cycles. This work highlights an innovative in situ vulcanization strategy to engineer oxide perovskite/metal sulfide nanocomposite catalysts for artificial photosynthesis of H2O2, opening new opportunities for achieving highly efficient photocatalyst systems.

Enhancement effect of potassium ferrate on self-activation: Significant improvement in pore structure and adsorption performance of activated carbon

This work developed a method using bamboo shoot shells as raw material to produce Fe-modified ACs combining self-activation and chemical modification. Adding small amounts (0.5–5 %) of K2FeO4 accelerated the pyrolysis process and CO2 release, and reduced the activation energy and temperature of self-activation reaction. This increased the reaction rate and activation efficiency, ultimately significantly improving the pore structure of ACs. The addition of 3 % K2FeO4 resulted in a substantial increase in specific surface area and pore volume of AC, from 1340 m2/g and 0.72 cm3/g to 2184 m2/g and 1.34 cm3/g, respectively. Additionally, the introduction of K2FeO4 also enabled iron doping on the surface of the ACs. The improvement of pore structure and iron doping further enhanced the adsorption performance of ACs. The adsorption capacities of ACs for arsenate, ibuprofen, and tetracycline were up to 1.64, 1.50, and 2.38 times higher, respectively, than those of ACs prepared through conventional self-activation.

Mechanistic Study on Oxygen Reduction Reaction in High-Concentrated Electrolytes for Aprotic Lithium-Oxygen Batteries.

Highly concentrated electrolytes (HCEs) have energized the development of high-energy-density lithium metal batteries by facilitating the formation of robust inorganic-derived solid electrolyte interfaces on the lithium anode. However, the oxygen reduction reaction (ORR) occurring on the cathode side remains ambiguous in HCE-based lithium-oxygen (Li-O2) batteries. Herein, we investigate the ORR mechanism in a highly concentrated LiTFSI-CH3CN electrolyte using ultra-microelectrode voltammetry coupled with in situ spectroscopies. It is found that, compared to the dilute electrolyte, the HCE prolongs the lifespan of superoxide intermediates and decelerates their migration rate to the bulk solution, resulting in a change in growth mode for the discharge product of Li2O2 from traditional two-dimensional film growth to surface three-dimensional expansion growth. This alteration reduces the cathode passivation and thus delivers the enhanced discharge capacity. Additionally, the HCE also increases the reaction energy barrier between superoxide and solvent molecules, thereby minimizing parasitic reactions and improving the cycle performance of Li-O2 batteries. Our study reveals the intricate interplay between electrolytes and oxygen intermediates and provides important insights into electrolyte chemistries for better Li-O2 batteries.

A Combined Physical-Mechanical and Hydrometallurgical Approach for Recovering Valuable Metals from Spent Lithium-ion Batteries

In this work, the chemical composition of electrode materials from two samples of lithium-ion batteries (LiB) is comprehensively investigated. The material balance of the physical and mechanical processing of the LiBs mixture is determined. The developed dry process scheme made it possible to extract the following components (wt.%): 15.6 plastic (ABS), 1.89 electronic materials (PP), 59.1 black mass (three types), 6.43 plastic (PVC), 2.97 Al, 6.31 Cu and 7.1 magnetic fraction (Fe). The thermodynamics of reductive leaching of LiCoO<sub>2</sub> in the H<sub>2</sub>SO<sub>4</sub>-HCOOH system was studied. It was calculated that the Gibbs energy of the leaching reaction at 363 K is -327.4 kJ/mol, the equilibrium constant is 2.02×10<sup>44</sup>. All these factors showed the potential of using formic acid as a reducing agent instead of the commonly used hydrogen peroxide solution. It is known to be unstable, since when the solution is heated from 20 to 50<sup>0</sup> C, the decomposition of H<sub>2</sub>O<sub>2</sub> increases 20 times, and the presence of copper sulfate, which usually accompanies the decomposition of the black mass in a sulfuric acid medium, leads to the destruction of 76% of hydrogen peroxide. Therefore, from a practical point of view, it was of interest to study the kinetics of cobalt dissolution from the cathode material in the H<sub>2</sub>SO<sub>4</sub>-HCOOH system. It was shown that the Crank-Ginstling-Braunstein equation agrees satisfactorily with the experimental data, which indicates intra-diffusion limitation of dissolution. The activation energy was determined. The optimal composition and conditions of the leaching solution for dissolving cobalt, lithium and associated transition metals from the black mass were determined. The thermodynamics and kinetics of dissolution of Ag, Au and Pd from electrode materials in a bromide-bromine solution were also studied.

Comparing low-temperature NH3-SCR activity, operating temperature window and kinetic properties of the Mn-Fe-Nb/TiO2 catalysts prepared by different methods

In order to overcome the shortcomings of traditional V-based catalysts, such as poor low-temperature activity, narrow temperature window, and toxicity. Therefore, the Mn-Fe-Nb/TiO2 catalysts were prepared using impregnation (IM), citric acid complexation (CA), co-precipitation (CP), hydrothermal synthesis (HY), and sol–gel (SG) methods to develop novel NH3 selective catalytic reduction (NH3-SCR) catalysts with excellent low-temperature activity, a wide temperature window, and environmental friendliness. Their NH3-SCR catalytic activity was evaluated, followed by a detailed analysis of their morphology, structure, specific surface area, chemical state, redox properties, acidity, and interactions using X-ray diffraction (XRD), Bruaner-Emmet-Teller (BET), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), NH3 temperature-programmed desorption (NH3-TPD), and Fourier transform infrared spectroscopy (FTIR) techniques. The 5Mn-7Fe-4Nb/TiO2-SG catalyst, prepared via sol–gel, exhibited the highest denitrification (de-NOx) activity and the widest operating temperature window, achieving over 80% Nitric oxide (NO) conversion at 180–350 °C and a peak conversion of 97% at 250 °C. The XRD, BET, SEM, and HR-TEM characterization results showed that the catalyst prepared using the sol–gel method had the smallest particles, the highest specific surface area, and the greatest dispersion. XPS and NH3-TPD results revealed that the catalyst prepared using the sol–gel method possessed the highest surface adsorbed oxygen (Oα) content and the largest number of acidic sites. H2-TPR and FTIR analyses indicated that the catalyst prepared using the sol–gel method enhanced the reduction capacity and possessed the strongest interaction forces among support-active-promoter components. Steady-state kinetic tests confirmed that in the NH3-SCR reaction, the rate-determining step was the adsorption activation of NO on the catalyst surface. The sol–gel method reduced the activation energy for de-NOx reactions, enhancing the low-temperature activity of the catalyst.

Theoretical study on the synthetic pathway of H and N co-doped diamonds

To search for potential n-type diamonds with shallow donor energy levels and low formation energies, the reaction energies, geometries, formation energies, electronic properties of hydrogen (H) and nitrogen (N) co-doped diamond have been investigated by density functional theory (DFT) and hybrid density functional theory (HSE06). The results of the investigations on isolated H- and N-doped diamonds do not meet the criteria for shallow n-type donors, in agreement with previous findings. Subsequently, the effect of the addition of N atoms as a co-dopant with H is investigated, which varies with the H:N ratio and whether H is substitutional or interstitial. By the results of the electronic structure, it is found that only the HN4 co-doped diamond is likely to exhibit a shallow donor, with a shallow donor level of 0.147 eV and formation energy of 0.02 eV. Then, the stability of the HN4 defect is analyzed, and the HN4 defect is more stable compared to the H-N3 + N and H-N2 + N2 defects, and its decomposition energy is also very large. Further, the bond strain brought by HN4 defect is considered, showing that the local bond strain of the HN4 defect is intermediate between that of the boron (B) and N defects, which proves that the defect can be realized. Finally, a non-molecular synthetic route for the preparation of HN4 defect is proposed by combining H-N + N3V or N2 + H-N2 defects.

Coordination Stabilization of Fe by Porphyrin‐Intercalated NiFe‐LDH Under Industrial‐Level Alkaline Conditions for Long‐Term Electrocatalytic Water Oxidation

AbstractThe durable and economic electrocatalysts with high current density under industrial alkaline conditions are critical for advancing the industrial production of hydrogen energy by water electrolysis. The industrial highly alkaline electrolyte exacerbates the Fe dissolution of NiFe layered double hydroxide (NiFe‐LDH), leading to the dramatic degradation of stability and activity. The NiFe‐LDH intercalated Tetrakis(4‐carboxyphenyl)porphyrin (TCPP) (NiFe‐TCPP), 1,4,7,10‐Tetraazacyclododecane‐1,4,7,10‐tetraacetic acid (DOTA) (NiFe‐DOTA) and CO32− (NiFe‐CO3) are fabricated respectively for electrocatalytic water oxidation under industrial alkaline conditions. In 10 m KOH, compared to NiFe‐DOTA (335.0 mV) and NiFe‐CO3 (499.2 mV), the resultant NiFe‐TCPP exhibits the lowest overpotentials of 290.2 mV at 1000 mA cm−2. The NiFe‐TCPP also operates continuously for 1000 h at 500 mA cm−2 with near‐zero attenuation. The theoretical and experimental studies reveal that the strong coordination between conjugated carboxylate ligand TCPP and Fe of the laminate inhibits the Fe leaching by increasing the dissolution energy barriers to 4.29 eV and improving the self‐healing ability, thus enhancing the stability. Furthermore, the charge redistribution induced by the strong coordination optimizes the d‐band centers (‐2.81 eV) and decreases the reaction energy barriers (1.47 eV), thereby increasing the catalytic activity.

P–N homojunction and heteroatom active site engineering over Fe2O3 nanorods for highly efficient photoelectrochemical water splitting

Limited charge transfer and slow oxygen evolution (OER) kinetics significantly impede the practical realization of photoanodes for photoelectrochemical (PEC) water splitting. Here, pn-type-Fe2O3 homojunction photoanode catalysts with P active sites are designed by doping phosphorus (P) into outer lattice of n-type Fe2O3 nanorods (pn-P-Fe2O3). The optimized pn-P-Fe2O3 photoanode shows the maximum photocurrent density of 2.61 mA/cm2 at 1.23 VRHE, and the value is 6.4 times greater than that of pristine Fe2O3. Experimental and theoretical results clearly show that the P–N homogeneous junctions constructed in Fe2O3 through P-doping increase active sites for H2O adsorption and activation, reduce OER reaction energy barrier, and promote effective separation of photogenerated electron-hole pairs and water splitting kinetics. This not only makes the photoelectric water decomposition performance outstanding, but also produces excellent durability. This work provides a novel simple and environmentally friendly strategy for designing effective photoanodes for PEC water splitting.

On the Heterogeneity of Iron‐Oxo Species in Zeolites for the Oxidation of Methane to Methanol by Nitrous Oxide: A Theoretical Perspective

AbstractThe conversion of methane to methanol (MTM) represents a pivotal objective in the C1 chemical industry. Transition metals, such as iron, exchanged zeolites are one category of the most active catalysts for direct conversion of MTM. One important topic in understanding the mechanism of Fe‐zeolite catalyzed MTM is how the heterogeneity of catalytic (Fe) sites influences the system stability and reactivity. Employing DFT calculations and machine learning method, we herein studied the stability–reactivity relationship of a MTM catalytic cycle with N2O as the oxidant over Fe‐exchanged zeolites. The Fe heterogeneity was introduced by using CHA and FER zeolites and looking at a number of related Fe species (FeII, FeO, and FeOH). A strong correlation was observed between the stability of such Fe species, which is primarily determined by the formation energy of FeII, and such a stability trend remains consistent throughout the MTM catalytic cycle. The reactivity analysis then demonstrated that less stable Fe species may exhibit higher reactivities when situated in specific sites. Further machine learning analysis validated the significant relevance of activation barriers with reaction energies in the N2O decomposition step that is not sufficiently captured by the traditional one‐dimensional Brønsted–Evans–Polanyi (BEP) relationship.

Reconstruction of Ferromagnetic/Paramagnetic Cobalt‐Based Electrocatalysts under Gradient Magnetic Fields for Enhanced Oxygen Evolution

AbstractThe rational manipulation of the surface reconstruction of catalysts is a key factor in achieving highly efficient water oxidation, but it is a challenge due to the complex reaction conditions. Herein, we introduce a novel in situ reconstruction strategy under a gradient magnetic field to form highly catalytically active species on the surface of ferromagnetic/paramagnetic CoFe2O4@CoBDC core–shell structure for electrochemical oxygen evolution reaction (OER). We demonstrate that the Kelvin force from the cores’ local gradient magnetic field modulates the shells’ surface reconstruction, leading to a higher proportion of Co2+ as active sites. These Co sites with optimized electronic configuration exhibit more favorable adsorption energy for oxygen‐containing intermediates and lower the activation energy of the overall catalytic reaction. As a result, a significant enhancement in OER performance is achieved with a large current density increment about 128 % at 1.63 V and an overpotential reduction by 28 mV at 10 mA cm−2 after reconstruction. Interestingly, after removing the external magnetic field, the activity could persist for over 100 h. This work showcases the directional surface reconstruction of catalysts under a gradient magnetic field for enhanced water oxidation.

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

AbstractElectrocatalytic 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.

Low LUMO energy carbon molecular interface to suppress electrolyte decomposition for fast charging natural graphite anode

Graphite holds great potential as a next-generation anode material for energy storage devices. However, the low working voltage of graphite leads to electrolyte decomposition, generating harmful byproducts like HF, while its anisotropic structure results in poor Li+ transport kinetics, making it challenging to balance battery stability and fast-charging performance. Herein, a controllable and scalable carbon molecular layer with low-LUMO (lowest unoccupied molecular orbital)energy is successfully designed to alter charge transfer at the electrode surface. The low LUMO energy carbon molecular interlayer between the graphite and solid electrolyte interphase (SEI) contains numerous strong electron-withdrawing and polar functional groups (C-F and C-N). The functional groups in the interlayer can preferentially and rapidly convert into a LiF and Li3N-rich SEI, attributed to their lower reaction energy barrier compared to electrolyte decomposition. Importantly, the electronic effects and intramolecular synergistic effects between polar functional groups make the conversion of C-F to LiF easier. The interayer superior properties that prevent SEI acid corrosion, accelerates the Li+ desolvation and diffusion in the SEI. Therefore, the graphite anode achieves a balance between fast charging and stability, retaining 64.28 % capacity retention after 1000 cycles at 10 A g−1. Additionally, the graphite anode can be applied in potassium-ion batteries, achieving 148.3 mAh g−1 at 0.2 A g−1. This simple and effective interfacial molecular design offers new insights for simultaneously regulating SEI and suppress electrolyte decomposition.

Rapid synthesis of solid polycarboxylate superplasticizers via photoinitiated radical polymerization

The synthesis and performance optimization of solid polycarboxylate superplasticizers (PCEs) present significant challenges. In our study, a rapid synthesis of a solid polycarboxylate superplasticizer (IPCE10) was achieved using photoinitiated free radical polymerization. IPCE10 exhibited good dispersibility and improved compressive strength in concrete. Dynamic light scattering tests and molecular dynamics simulations demonstrated that the adsorption conformation of IPCE10 on the calcium silicate hydrate surface was relatively dispersed, with a thicker adsorption layer. This indicates that IPCE10 has stronger steric hindrance, resulting in superior dispersibility. Additionally, density functional theory calculations of the reaction energy barriers for radical generation by photoinitiated and azo-initiated monomers revealed that the energy barrier in the photoinitiated system was significantly lower than that in the azo-initiated system, indicating that photoinitiated polymerization is more feasible. This study proposes a simple and rapid method for the preparation of solid polycarboxylate superplasticizers, providing valuable insights for the development of high-value-added construction materials.

Coulomb interaction dependence of optimal energy to synthesize superheavy elements

The production of superheavy elements beyond Z = 118 remains unattained through both cold and hot fusion techniques, primarily due to inadequate fusion reaction optimization involving projectile–target combinations and energy. Past efforts employed various theories to optimize these combinations. In our current study, we have successfully identified optimal fusion energies for synthesizing superheavy elements, employing an advance statistical model and dinuclear system models. The establishment of optimal energy governing rule is achieved through a comprehensive examination of the Coulomb interaction parameter, enabling precise determination of the optimal energy for successful fusion reactions in synthesizing superheavy elements. The confidence level of predicting optimal energies using the present formula varies between 97% to 99%. The predicted optimal energy using the present formula for five fusion reactions such as 208Pb(50Ti,1n)257Rf, 208Pb(50Ti,2n)256Rf, 209Bi(50Ti,1n)258Db, 208Pb(58Fe,1n)265Hs, and 244Pu(48Ca,4n)288Fl were studied and are in good agreement with each other. Furthermore, we predicted the Optimal energies for fusion reactions leading to synthesize the superheavy element Z = 119 and 120. The presented empirical rule will certainly bring a revolution in the synthesis of superheavy elements.

Artificially regulated interphase on natural graphite realizes rapid charge and durable high-temperature cycling of Li-ion batteries

Natural graphite (NG) is a strong competitor in the anode market of Li-ion batteries because of its low cost, rich resource, low energy consumption and low carbon dioxide emission during production. The main problems inhibiting its universal application are its high surface area and the attendant unstable solid/electrolyte interphase (SEI), leading to unsatisfactory cycling and rate performance. In this work, a Li+-conductive, thermally and mechanically stable organic polymer layer is successfully constructed on NG surface by virtue of the simultaneous polymerization and crosslinking reactions of chitosan (CS) and acrylic acid (AA). With controllable thickness, the polymer layer denoted as CSAA significantly decreases the specific surface area of NG, works as an inner SEI substrate greatly mitigating the decomposition of electrolyte, and induces the formation of a LiF-rich SEI outer layer. The SEI resistance and activation energy for charge-transfer reactions are considerably reduced. Benefiting from the superior properties of CSAA-derived SEI, the NG@CSAA anodes exhibit a high initial coulombic efficiency of 94.1 %, fast charge/discharge capability and prolonged cycle life at both 25 °C and 45 °C in the LiFePO4 cathodes-based full cells.

Mg-Doped Cu Catalyst for Electroreduction of CO2 to Multicarbon Products: Lewis Acid Sites Simultaneously Promote *CO Adsorption and Water Dissociation.

The electroreduction of CO2 to valuable fuels or high-value chemicals by using sustainable electric energy provides a promising strategy for solving environmental problems dominated by the greenhouse effect. Copper-based materials are the only catalysts that can convert CO2 into multicarbon products, but they are plagued by high potential, low selectivity, and poor stability. The key factors to optimize the conversion of CO2 into multicarbon products are to improve the adsorption capacity of intermediates on the catalyst surface, accelerate the hydrogenation step, and improve the C-C coupling efficiency. Herein, we successfully doped Lewis acid Mg into Cu-based materials using a simple liquid-phase chemical method. In situ Raman and FT-IR tracking show that the Mg site enhances the surface coverage of the *CO intermediate, simultaneously promoting water dissociation. Under an industrial current density of 0.7 A cm-2, the FEC2+ reaches 73.9 ± 3.48% with remarkable stability. Density functional theory studies show that doping the Lewis acid Mg site increases the coverage of *CO and accelerates the splitting of water, thus promoting the C-C coupling efficiency, reducing the reaction energy barrier, and greatly improving the selectivity of C2+ products.

Elementary steps of catalytic reactions occurring on metallic alloy nanoparticles

Catalytic reactions occurring in an adsorbed overlayer on metallic alloy nanoparticles are of high interest in the context of applications in the chemical industry. The understanding of the corresponding kinetics is, however, still limited. One of the reasons of this state of the art is the interplay between adsorption and adsorbate‐influenced segregation of metal atoms inside alloy nanoparticles. I scrutinize this interplay by using a generic field model of segregation and the mean‐field approximation in order to describe adsorption, desorption, and elementary catalytic reactions. Under steady‐state conditions, the segregation is demonstrated to be manifested in the change of the dependence of the activation energies of desorption or elementary reactions on coverage, and the sign of this change is positive. The effect of this change on the apparent reaction orders is briefly discussed as well.