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Direct observation of the capture cross section is challenging due to the need for extremely short filling pulses in the two-gate Deep-Level Transient Spectroscopy (DLTS). Simple estimation of the cross section can be done from DLTS and admittance spectroscopy data but it is not feasible to distinguish temperature dependence of pre-exponential and exponential parts of the emission rate equation with sufficient precision conducting a single experiment. This paper presents experimental data of deep levels in β-Ga2O3 that has been gathered by our group since 2017. Based on the gathered data, we propose a derivation of apparent activation energy (E a m) and capture cross section (σ n m) assuming the temperature dependent capture via the multiphonon emission model, which resulted in a strong correlation between E a m and σ n m according to the Meyer–Neldel rule, which allowed us to estimate low- and high-temperature capture coefficients C 0 and C 1 as well as capture barrier E b. It also has been shown that without considering the temperature dependence of capture cross section, the experimental values of σ n are overestimated by 1–3 orders of magnitude. A careful consideration of the data also allows to be more certain identifying deep levels by their "fingerprints" (E a and σ n) considering two additional parameters (E M N and σ 00) and to verify the density functional theory computation of deep-level recombination properties. [ABSTRACT FROM AUTHOR]

Direct observation of the capture cross section is challenging due to the need for extremely short filling pulses in the two-gate Deep-Level Transient Spectroscopy (DLTS). Simple estimation of the cross section can be done from DLTS and admittance spectroscopy data but it is not feasible to distinguish temperature dependence of pre-exponential and exponential parts of the emission rate equation with sufficient precision conducting a single experiment. This paper presents experimental data of deep levels in β-Ga2O3 that has been gathered by our group since 2017. Based on the gathered data, we propose a derivation of apparent activation energy (E a m) and capture cross section (σ n m) assuming the temperature dependent capture via the multiphonon emission model, which resulted in a strong correlation between E a m and σ n m according to the Meyer–Neldel rule, which allowed us to estimate low- and high-temperature capture coefficients C 0 and C 1 as well as capture barrier E b. It also has been shown that without considering the temperature dependence of capture cross section, the experimental values of σ n are overestimated by 1–3 orders of magnitude. A careful consideration of the data also allows to be more certain identifying deep levels by their "fingerprints" (E a and σ n) considering two additional parameters (E M N and σ 00) and to verify the density functional theory computation of deep-level recombination properties. [ABSTRACT FROM AUTHOR]

We construct the effective Hartree potential for H2 on Cu(111) as introduced in our earlier work [Dutta et al., J. Chem. Phys. 154, 104103 (2021), and Dutta et al., J. Chem. Phys. 157, 194112 (2022)] starting from the same gas–metal interaction potential obtained for 0 K. Unlike in that work, we now explicitly account for surface expansion at 925 K and investigate different models to describe the surface vibrational modes: (i) a cluster model yielding harmonic normal modes at 0 K and (ii) slab models resulting in phonons at 0 and 925 K according to the quasi-harmonic approximation—all consistently calculated at the density functional theory level with the same exchange–correlation potential. While performing dynamical calculations for the H2(v = 0, j = 0)–Cu(111) system employing Hartree potential constructed with 925 K phonons and surface temperature, (i) the calculated chemisorption probabilities are the highest compared to the other approaches over the energy domain and (ii) the threshold for the reaction probability is the lowest, in close agreement with the experiment. Although the survival probabilities (v′ = 0) depict the expected trend (lower in magnitude), the excitation probabilities (v′ = 1) display a higher magnitude since the 925 K phonons and surface temperature are more effective for the excitation process compared to the phonons/normal modes obtained from the other approaches investigated to describe the surface. [ABSTRACT FROM AUTHOR]

Improving the catalytic performance of materials based on cerium oxide (CeO2) for the activation of methane (CH4) can be achieved through the following strategies: mixture of CeO2 with different oxides (e.g., CeO2–La2O3) and the use of particles with different sizes. In this study, we present a theoretical investigation of the initial CH4 dehydrogenation on (La2Ce2O7)n clusters, where n = 2, 4, and 6. Our framework relies on density functional theory calculations combined with the unity bond index–quadratic exponential potential approximation. Our results indicate that chemical species arising from the first dehydrogenation of CH4, that is, CH3 and H, bind through the formation of C–O and H–O bonds with the clusters, respectively. The coordination of the adsorption site and the chemical environment plays a crucial role in the magnitude of the adsorption energy; for example, species adsorb more strongly in the low-coordinated topO sites located close to the La atoms. Thus, it affects the activation energy barrier, which tends to be lower in configurations where the adsorption of the chemical species is stronger. During CH4 dehydrogenation, the CH3 radical can be present in a planar or tetrahedral configuration. Its conformation changes as a function of the charge transference between the molecule and the cluster, which depends on the CH3-cluster distance. Finally, we analyze the effects of the Hubbard effective parameter (Ueff) on adsorption properties, as the magnitude of localization of Ce f-states affects the hybridization of the interaction between the molecule and the clusters and hence the magnitude of the adsorption energies. We obtained a linear decrease in the adsorption energies by increasing the Ueff parameter; however, the activation energy is only slightly affected. [ABSTRACT FROM AUTHOR]

Metal–Organic Polymers (MOPs) have attracted growing attention for lithium-ion battery (LIB) applications due to their merits in orderly ionic transportation and robust structure stability in electrochemical reactions. However, they suffer from poor electronic conductivity. In this work, we apply first-principles density functional theory to explore the potential of three one-dimensional (1D) electrically conductive C6H2S4TM (TM = Fe, Co, and Ni) MOPs with the π–d conjugated coordination as anode materials for Li+ ions storage. Our theoretical results reveal that these 1D MOPs possess a superior theoretical capacity of over 748 mA h g−1. In particular, the 1D C6H2S4Ni MOP shows an exceptional theoretical specific capacity of 1110 mA h g−1 based on the three-electron transferring reaction, which significantly outperforms the traditional graphite-based anode material in LIBs. Moreover, the resonant charge transfer between Ni metal and ligand within the 1D C6H2S4Ni MOP reduces the diffusion energy barrier of the Li atoms when they migrate on the surface of the MOP. The ultrahigh theoretical specific capacity of the C6H2S4Ni MOP predicts that it can be a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

Cd-doped ZrO2 catalyst has been found to have high selectivity and activity for CO2 hydrogenation to methanol. In this work, density functional theory calculations were carried out to investigate the microscopic mechanism of the reaction. The results show that Cd doping effectively promotes the generation of oxygen vacancies, which significantly activate the CO2 with stable adsorption configurations. Compared with CO2, gaseous H2 adsorption is more difficult, and it is mainly dissociated and adsorbed on the surface as [HCd–HO]* or [HZr–HO]* compact ion pairs, with [HCd–HO]* having the lower energy barrier. The reaction pathways of CO2 to methanol has been investigated, revealing the formate path as the dominated pathway via HCOO* to H2COO* and to H3CO*. The hydrogen anions, HCd* and HZr*, significantly reduce the energy barriers of the reaction. [ABSTRACT FROM AUTHOR]

Cd-doped ZrO2 catalyst has been found to have high selectivity and activity for CO2 hydrogenation to methanol. In this work, density functional theory calculations were carried out to investigate the microscopic mechanism of the reaction. The results show that Cd doping effectively promotes the generation of oxygen vacancies, which significantly activate the CO2 with stable adsorption configurations. Compared with CO2, gaseous H2 adsorption is more difficult, and it is mainly dissociated and adsorbed on the surface as [HCd–HO]* or [HZr–HO]* compact ion pairs, with [HCd–HO]* having the lower energy barrier. The reaction pathways of CO2 to methanol has been investigated, revealing the formate path as the dominated pathway via HCOO* to H2COO* and to H3CO*. The hydrogen anions, HCd* and HZr*, significantly reduce the energy barriers of the reaction. [ABSTRACT FROM AUTHOR]

Nickel-doped β-Ga2O3 crystals were investigated by optical absorption and photoconductivity, revealing Ni-related deep levels. The photoconductivity spectra were fitted using the phenomenological Kopylov and Pikhtin model to identify the energy of the zero-phonon transition (thermal ionization), Franck–Condon shift, and effective phonon energy. The resulting values are compared with the predicted ones by first-principle calculations based on the density functional theory (DFT). An acceptor level (0/−) of 1.9 eV and a donor level (+/0) of 1.1 eV above the valence band minimum are consistently determined for NiGa, which preferentially incorporates on the octahedrally coordinated Ga site. Temperature-dependent resistivity measurements yield a thermal activation energy of ∼2.0 eV that agrees well with the determined Ni acceptor level. Conclusively, Ni is an eminently suitable candidate for compensation doping for producing semi-insulating β-Ga2O3 substrates due to the position of the acceptor level (below and close to the mid-bandgap). [ABSTRACT FROM AUTHOR]

To improve the performance of Cu(In,Ga)Se2 thin-film photovoltaic devices, a robust understanding of the dominant diffusion pathways of the alloy species In and Ga is needed. Here, the most probable defect complexes and mechanisms for In and Ga diffusion are identified with the aid of density functional theory. The binding energies and migration barriers for these complexes are calculated in bulk CuInSe2 and CuGaSe2. Analytic models and kinetic lattice Monte Carlo simulations are employed to predict the diffusivity of In and Ga under variations in composition and temperature. We find that a model based on coulombic interactions between group III antisites and vacancies on the Cu-sublattice produces results that match well with experiment. [ABSTRACT FROM AUTHOR]

To improve the performance of Cu(In,Ga)Se2 thin-film photovoltaic devices, a robust understanding of the dominant diffusion pathways of the alloy species In and Ga is needed. Here, the most probable defect complexes and mechanisms for In and Ga diffusion are identified with the aid of density functional theory. The binding energies and migration barriers for these complexes are calculated in bulk CuInSe2 and CuGaSe2. Analytic models and kinetic lattice Monte Carlo simulations are employed to predict the diffusivity of In and Ga under variations in composition and temperature. We find that a model based on coulombic interactions between group III antisites and vacancies on the Cu-sublattice produces results that match well with experiment. [ABSTRACT FROM AUTHOR]

The present work gives the structural, dehydriding and electronic characteristics of MgH 2 with Ti or/and S additives by first-principles density functional theory calculations. It is found that Ti and S prefer to occupy Mg site and interstitial site, respectively, in terms of occupation energy (E occ). Furthermore, Ti + S incorporation into MgH 2 lattice is more energetically favorable (E occ = −0.051 eV–0.944 eV) relative to single Ti incorporation (E occ = 1.314 eV–1.784 eV), for which the promotion of adequate Mg site by S addition is chiefly responsible. Ti, S, and especially Ti + S doping not only reduce the hydrogen dissociation energy from 1.619 eV/2.317 eV (Mg 16 H 32) to 0.350 eV/0.967 eV (Mg 15 TiSH 32) for H-atom/H-molecule desorption, but also decrease the hydrogen diffusion energy barrier from 0.706 eV/0.704 eV (Mg 16 H 32) to 0.342 eV/0.169 eV (Mg 15 TiSH 32) along path I/II, respectively. As a result, a significant improvement on the thermodynamical and kinetical performance of MgH 2 can be achieved using Ti or/and S. This improvement is attributed to the higher electronegativity of Ti (relative to Mg), the decrease of Mg–H interaction and the formation of Ti–H and Mg–S bonds. Our studies provide new insight into the enhanced dehydrogenation of MgH 2 modified by Ti and S, which is useful for designing advanced magnesium hydrides with favorable H-desorption performance. • Enhanced dehydrogenation of MgH 2 with Ti or/and S additives is investigated theoretically. • Ti, S and especially Ti + S effectively modify the thermodynamics and kinetics of MgH 2. • Decrease of Mg–H interaction leads to destabilized MgH 2 for favorable H-desorption. • Formation of Ti–H and Mg–S bonds in Ti or/and S doped MgH 2 favors for H-desorption. [ABSTRACT FROM AUTHOR]

Aqueous zinc batteries based on the conversion‐type sulfur cathodes are promising in energy storage system due to the high theoretical energy density, low cost, and good safety. However, the multi‐electron solid‐state intermediate conversion reaction of sulfur cathodes generally possess sluggish kinetics, which leads to lower discharge voltage and inefficient sulfur utilization, thus suppressing the practical energy density. Herein, sulfur nanoparticles derived from metal–organic frameworks confined in situ within electrospun fibers derived sulfur and nitrogen co‐doped carbon nanofibers (S@S,N−CNF) composite, which possesses yolk–shell S@C nanostructure, is fabricated through successive sulfidation, pyrolysis, and sulfide oxidation processes, and served as a high‐performance cathode material for Zn−S battery. The S and N dopants on carbon can collectively catalyse sulfur reduction reaction (SRR) by lowering energy barrier and accelerating kinetics to increase discharge voltage and specific capacity. Meanwhile, the yolk–shell S@C structure with spatially confined S nanoparticle yolks is beneficial to improve charge transfer and lower activation energy, thus further expediting SRR kinetics. Furthermore, extensive density functional theory (DFT) calculations reveal that S and N dual‐doping can thermodynamically and dynamically reduce the energy barrier of rate‐determining step (i.e., the transformation of *ZnS4 into *ZnS2) for the overall SRR, thereby significantly accelerating SRR kinetics. [ABSTRACT FROM AUTHOR]

A facile synthesis of Pt-Rh 2 O 3 /CN x composite is reported for superior electrocatalytic hydrogen evolution and oxidation reaction (HER/HOR) in base. The HER/HOR performance of Pt-Rh 2 O 3 /CN x is ∼6/3.4 times better than commercial Pt/C. Both the hydrogen and hydroxyl binding energy are equal descriptors for alkaline HER/HOR. The hydrogen spillover from Pt to Rh 2 O 3 enhances the HER/HOR performance. The role of hydroxyl-metal-water species on alkaline HOR was also discussed. [Display omitted] • The Platinum/Rhodium Oxide-Nitrogen-Doped Carbon (Pt/Rh 2 O 3 -CN x) nanocomposite was prepared for bifunctional HER/HOR in base media. • The HOR/HER activities of Pt/Rh 2 O 3 -CN x are ∼ 3.5/6 times higher than commercial Pt/C. • Experimental, theoretical studies suggest H-spillover increases catalytic activity. • HBE and OHBE are responsible for alkaline HER/HOR; a bifunctional mechanism was proposed. • Interfaces, porosity, ECSA, and synergetic interactions also helped for high activity. The poor activity of Pt-based-catalysts for alkaline hydrogen oxidation/evolution reaction (HOR/HER) encourages scientific society to design an effective electrocatalyst to develop alkaline fuel cells/electrolyzers. Herein, platinum/rhodium oxide-nitrogen-doped carbon (Pt/Rh 2 O 3 -CN x) composite is prepared for alkaline HER and HOR inspired by hydrogen spillover. The HER performance of Pt/Rh 2 O 3 -CN x is ∼ 6 times higher than Pt/C. In HOR, Pt/Rh 2 O 3 -CN x possesses an exchange current density of 657.60 mA/mg metal , which is ∼ 3.4 times higher than Pt/C. Hydrogen and hydroxyl binding energy (HBE and OHBE) contribute equally to alkaline HOR/HER. The experimental and theoretical evidence suggests that the enhanced HER and HOR activity of Pt/Rh 2 O 3 -CN x may be due to hydrogen spillover from Pt to Rh 2 O 3. Small work function difference [0.08 eV] of the system suggested hydrogen-spillover is feasible, which has been justified by reaction-free energy calculations. We proposed that the dissociation of hydrogen (H 2) and water (H 2 O) occurs at Pt to form Pt-adsorbed hydrogen species (Pt-H ad). Then, some H ad moves to Rh 2 O 3 through hydrogen spillover and reacts with neighboring H ad or adsorbed hydroxyl species (OH ad) to form H 2 or H 2 O, which enhances the HER and HOR activity, respectively. The role of water-metal-hydroxyl species in the electrical double layer was also demonstrated on alkaline HOR/HER. This work may help to design the hydrogen-spillover-based catalysts for several renewable energy technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Newly synthesized Cu 3 N catalyst was employed for electrocatalytic nitrate reduction and ammonia production. • The strategy of balancing *H 2 O and *NO 3 intermediates adsorption for enhanced NO 3 RR was highlighted. • In-situ and ex-situ analysis verify the potential driven reconstruction and rehabilitation of Cu 3 N. Nitrate in surface and underground water caused systematic risk to the ecological environment. The electrochemically reduction of nitrate into ammonia (NO 3 RR), offering a sustainable route for nitrate containing wastewater treatment and ammonia fertilizer conversion. Exploration of catalyst with improved catalytic activity with lower energy barriers is still challenging. Here, we report a copper nitride (Cu 3 N) catalyst with moderate *NO x and *H 2 O intermediates adsorptions showed enhanced NO 3 RR performance. Density functional theory calculations reveals that the unique electronic structure of Cu 3 N provides efficient active sites for NO 3 RR, thus enabled balanced adsorption of *NO 3 and *H 2 O (ΔE descriptor), sufficient active hydrogen, and moderate intermediate (*NO 3 → HNO 3 , *NH 2 →*NH 3) adsorption energy. Notably, the in-situ analysis technology revealed potential-driven reconstruction and rehabilitation of Cu 3 N, forming possible nitrogen vacancy, thus implied for better mechanism understanding. The NO 3 RR activity of Cu 3 N surpasses that of most recent catalysts and demonstrates superior stability and implies the application for NH 4 + fertilizer recovery, which maintaining an NH 3 Faradaic efficiency of 93.1 % and high yield rate of 2.9 mg cm2h−1 at −0.6 V versus RHE. These findings broaden the application scenarios of Cu 3 N catalyst for ammonia synthesis and provide strategy on improving NO 3 RR performance. [ABSTRACT FROM AUTHOR]

To investigate hydrogen behaviors in the high-entropy alloy AlCrTiNiV, density functional theory and transition state theory were used to explore the molecular H 2 absorption and dissociation and the atomic H adsorption, diffusion, and penetration progress. The H 2 molecule, where the H-H band is parallel to the surface layer, is more inclined to absorb on the top site of the Ti atom site of first atomic layer on the AlCrTiNiV surface, then diffuse into the hollow sites, through the bridge site, after dissociating into two H atoms. Atomic H is more likely to be absorbed on the hollow site. The absorption capacity for atomic H on the surface tends to decline with the increase in H coverage. By calculating the energy barriers of atomic H penetration in AlCrTiNiV, it was indicated that lattice distortion may be one important factor that impacts the permeation rate of hydrogen. Our theory research suggests that high-entropy alloys have potential for use as a hydrogen resistant coating material. [ABSTRACT FROM AUTHOR]

Highly dispersed Pd/N-doped carbon dots (Pd/NCDs) were successfully immobilized in the mesoporous channels of amino-functionalized dendritic mesoporous silica nanospheres (NMS). The synthesized Pd/NCDs@NMS catalyst exhibits outstanding performance in the catalytic reduction of 4-nitrophenol (4-NP), achieving a turnover frequency of 1461.8 mol·molPd−1·h−1, with the conversion rate remaining above 80% after 11 cycles. Experiments and density functional theory calculations reveal that the NCDs significantly affect the electronic structure of Pd nanoparticles, leading to changes in the energy barriers for the adsorption of 4-NP at the Pd sites and the conversion of 4-NP reaction intermediates, which is a key factor contributing to the catalytic performance. This study offers a new strategy for synthesizing carbon-dot-modified metal-based catalysts. [ABSTRACT FROM AUTHOR]

Elucidation the relationship between electrode potentials and heterogeneous electrocatalytic reactions has attracted widespread attention. Herein we construct the well-defined Mn single-atom (MnSA) catalyst with four N-coordination through a simple thermal pyrolysis preparation method to investigate the electrode potential micro-environments effect on carbon dioxide reduction reactions (CO2RR) and oxygen reduction reactions (ORR). MnSA catalysts generate higher CO production Faradaic efficiency of exceeding 90% at −0.9 V for CO2RR and higher H2O2 yield from 0.1 to 0.6 V with excellent ORR activity. Density functional theory (DFT) calculations based on constant potential models were performed to study the mechanism of MnSA on CO2RR. The thermodynamic energy barrier of CO2RR is lowest at −0.9 V vs. reversible hydrogen electrode (RHE). Similar DFT calculations on the H2O2 yield of ORR showed that the H2O2 yield at 0.2 V was higher. This study provides a reasonable explanation for the role of electrode potential micro-environments. [ABSTRACT FROM AUTHOR]

Oxide-supported metal single-atom catalysts (SACs) have exhibited excellent catalytic performance for water–gas shift (WGS) reaction. Here, we report the single-atom catalyst Pt1/FeOx exhibits excellent medium temperature catalytic performance for WGS reactions by the density functional theory (DFT) calculations and experimental results. The calculations indicate that H2O molecules are easily dissociated at oxygen vacancies, and the formed ⋆OH and ⋆O are adsorbed on Pt1 single atoms and the adjacent O atoms, respectively. After studying four possible reaction mechanisms, it is found that the optimal WGS reaction pathway is proceeded along the carboxyl mechanism (pathway III), in which the formation of ⋆COOH intermediates can promote the stability of Pt1/FeOx SAC and the easier occurrence of WGS reaction. The energy barrier of the rate-determining step during the entire reaction cycle is only 1.16 eV, showing the high activity for the medium temperature WGS reaction on Pt1/FeOx SAC, which was verified by experimental results. Moreover, the calculated turnover frequencies (TOFs) of CO2 and H2 formation on Pt1/FeOx at 610 K (337 °C) can reach up to 1.14 × 10−3 s−1·site−1 through carboxyl mechanism. In this work, we further expand the application potential of Pt1/FeOx SAC in WGS reaction. [ABSTRACT FROM AUTHOR]

Iron or its oxides (FexOy) commonly exist in the ash of fossil fuel and biomass, and are used as oxygen carriers in chemical looping process, and Fe3O4 is a main occurrence. The NO reduction mechanisms by CO over Fe3O4 (111) surface was investigated via density functional theory (DFT) calculations. An optimized unit cell of Fe3O4 was constructed. The interaction between molecules and cell surface was described by the calculated adsorption properties and electronic structures. Results showed that the most stable adsorption of NO/CO belongs to chemisorption and NO has higher adsorption energy than CO. NO can be absorbed onto Fe3O4 surface to form (NO)2 dimer structure, which easily decomposes via a small energy barrier. (NO)2 dimer mechanism is a possible pathway for the reduction of NO by CO over Fe3O4, following three steps: 2NO → (NO)2*, (NO)2* → N2O + O*, O* + CO* → CO2. After the decomposition, the intermediate species N2O molecule and the remaining O atom adsorbed strongly on the Fe3O4 surface can be removed by CO. CO also promotes the gaseous decomposition of N2O. DFT results also showed O2 will prevent NO reduction reaction. The calculated reaction rate constants further verify the existence of (NO)2 dimer mechanism and the rate-limiting step is the removal of the surface O atom. [ABSTRACT FROM AUTHOR]

Ionic liquid (IL) can not only serve as solvents to reduce carbon capture energy consumption, but also may activate the CO2 absorption of amine solutions. Here, the absorption mechanism and kinetic modeling of IL‐activated single and mixed amines were studied in wetted wall column. N‐(2‐aminoethyl) ethanolamine (AEEA) and N,N‐diethylethanolamine (DEEA) were used as representatives to evaluate the IL activation effects on primary and tertiary amines. It was found that IL activated the reaction process of primary amine, but had no activation effect on tertiary amine. The activation energy of AEEA‐IL‐CO2 was 22.2 kJ/mol, which was 21.0% lower than AEEA‐CO2. Kinetic modeling of IL‐activated AEEA and mixed amines was established. Besides, the density functional theory calculations showed that IL can form hydrogen bonding and other interactions with AEEA and CO2 to activate the absorption reaction, which can reduce 29.3% activation energy during the zwitterion formation stage. [ABSTRACT FROM AUTHOR]

Fe2O3 supported LaMnO3 is an effective selective catalytic reduction (SCR) denitrification catalyst, but its reaction mechanism has not been reported yet. This article is based on the density functional theory (DFT) method to study the denitrification reaction mechanism of LaMnO3/Fe2O3 catalyst, in order to guide the development and application of denitrification catalysts. The conclusion is as follows: NH3, NO, and O2 molecules can form stable adsorption on the surface of La MnO3/γFe2O3 catalysts, and NH3 molecules are more likely to be adsorbed on Mn ions. Under the oxidation of lattice oxygen, NH3 will gradually dehydrogenate to form NH2, and then will react with NO in the air to form the transitional intermediate NH2NO, to produce N2 and H2O. The mechanisms are same on Mn and Fe sites. The dehydrogenate of NH3 to form NH2 is rate determining step. Compared with pure γFe2O3, the energy barrier decreases to promote the SCR process. [ABSTRACT FROM AUTHOR]

Directly electrochemical conversion of nitrate (NO3−) is an efficient and environmentally friendly technology for ammonia (NH3) production but is challenged by highly selective electrocatalysts. High‐entropy alloys (HEAs) with unique properties are attractive materials in catalysis, particularly for multi‐step reactions. Herein, we first reported the application of HEA (FeCoNiAlTi) for electrocatalytic NO3− reduction to NH3 (NRA). The bulk HEA is active for NRA but limited by the unsatisfied NH3 yield of 0.36 mg h−1 cm−2 and Faradaic efficiency (FE) of 82.66 %. Through an effective phase engineering strategy, uniform intermetallic nanoparticles are introduced on the bulk HEA to increase electrochemical active surface area and charge transfer efficiency. The resulting nanostructured HEA (n‐HEA) delivers enhanced electrochemical NRA performance in terms of NH3 yield (0.52 mg h−1 cm−2) and FE (95.23 %). Further experimental and theoretical investigations reveal that the multi‐active sites (Fe, Co, and Ni) dominated electrocatalysis for NRA over the n‐HEA. Notably, the typical Co sites exhibit the lowest energy barrier for NRA with *NH2 to *NH3as the rate‐determining step. [ABSTRACT FROM AUTHOR]

The extensive industrial applications of fuel oil, a critical strategic resource, are accompanied by significant environmental and health concerns due to the presence of sulfur‐containing compounds in its composition, which result in hazardous combustion waste. Extensive research has been conducted to develop technologies for low‐vulcanization fuel production to address this issue. Consequently, the investigation of catalysts for environmentally friendly and safe photocatalytic desulfurization becomes imperative. To that end, we have designed efficient MIL‐101(Fe)/CQDs@g‐C3N4 (MIL101/CDs‐C3N4) Z‐scheme heterojunction photocatalysts with high carrier separation and mobility through a thermal polymerization‐hydrothermal strategy. The high concentration of photogenerated carriers facilitates the activation of oxygen and H2O2, leading to increased production of ROS (⋅O2−, ⋅OH, h+), thereby enhancing the photocatalytic desulfurization (PODS). Additionally, DFT (Density functional theory) calculations were utilized to determine the electron migration pathways of the catalysts and adsorption energies of DBT (dibenzothiophene). Moreover, Gibbs free energy calculations indicated that MIL101/CDs‐C3N4 exhibited the lowest activation energy for oxygen and H2O2. The mechanism of photocatalytic desulfurization was proposed through a combination of theoretical calculations and experimental studies. This study provides guidance for the development of MOF‐based Z‐scheme systems and their practical application in desulfurization processes. [ABSTRACT FROM AUTHOR]

Bismuth‐based materials have emerged as promising catalysts in the electrocatalytic reduction of CO2 to formate. However, the reasons for the reconstruction of Bi‐based precursors to form bismuth nanosheets are still puzzling, especially the formation of defective bismuth sites. Herein, we prepare bismuth nanosheets with vacancy‐rich defects (V‐Bi NS) by rapidly reconstructing Bi19Cl3S27 under negative potential. Theoretical analysis reveals that the introduction of chlorine induces the generation of intrinsic electric field in the precursor, thereby increasing the electron transfer rate and further promoting the metallization of trivalent bismuth. Meanwhile, experimental tests verify that Bi19Cl3S27 has a faster reconstruction rate than Bi2S3. The formed V‐Bi NS exhibits up to 96 % HCOO− Faraday efficiency and 400 mA cm−2 HCOO− partial current densities, and its electrochemical active surface area normalized formate current density and yield are 2.2 times higher than those of intact bismuth nanosheets (I‐Bi NS). Density functional theory calculations indicate that bismuth vacancies with electron‐rich aggregation reduce the activation energy of CO2 to *CO2− radicals and stabilize the adsorption of the key intermediate *OCHO, thus facilitating the reaction kinetics of formate production. [ABSTRACT FROM AUTHOR]

Sustaining the steady state for highly active non‐stoichiometric iridium (Ir)‐based oxide (IrOx) at low Ir loading remains challenging primarily due to the continuous oxidation and sequent dissolution of Ir active sites during the oxygen evolution reaction (OER). In this context, a new iridium–cerium (Ce) substitution solid solution oxide (SSO) has been developed, featuring uniformly dispersed Ir atoms within Ce dioxide (CeO2) matrix as electron buffer, which delivers remarkable acidic OER catalytic activity and enhanced stability. The electron‐buffering capacity of CeO2 facilitates the charge transfer toward Ir atoms, leading to abundant active low‐valence Ir sites and effectively prevent their oxidation and dissolution. As a result, Ir─Ce SSO demonstrates an overpotential of merely 238 mV@10 mA cm−2. Proton exchange membrane water electrolyzer employing Ir─Ce SSO at a low Ir loading of 396 µgIr cm−2 operates consistently for over 100 h@500 mA cm−2. Density functional theory (DFT) calculations corroborate that the electron‐buffering effect of CeO2 enriches the density of IrIII and substantially increases the dissolution energy barrier of Ir atoms. This study presents a viable approach to addressing the issues of instability and low efficiency in Ir‐based OER electrocatalysts for acidic water electrolysis. [ABSTRACT FROM AUTHOR]

Heptafluoro-iso-butyronitrile (i-C3F7CN) represents a feasible eco-friendly replacement gas for the most potent greenhouse gas sulfur hexafluoride in various high-voltage power transmission equipment. The reaction mechanisms for the in situ synthesis of i-C3F7CN from heptafluoro-iso-butyramide [i-C3F7C(O)NH2] in the presence of trifluoroacetic anhydride (TFAA) and pyridine (Py) in dimethylformamide solution have been studied within density functional theory with M06-2X exchange–correlation functional with the 6-311++G(d,p) basis set and the high-level ab initio complete basis set quadratic CBS-QB3 method. It is revealed that the unimolecular dehydration of i-C3F7C(O)NH2 can be catalyzed efficiently by TFAA in terms of both kinetic and thermodynamic aspects, producing i-C3F7CN and trifluoroacetic acid (TFA). Furthermore, Py is capable of reducing the energy barrier of the rate-determining step through hydrogen abstraction to form pyridinium hydrogen. The synergic effect of the TFAA/Py co-catalyst plays a pivotal role in the production of i-C3F7CN as the Gibbs free energy barrier can be lowered by more than 40 kcal/mol with the ratio of TFAA:2Py, in accordance with the experimental observation. The present theoretical work provides new insights into the rational design on the novel catalysts for large-scale synthesis of the perfluorinated nitriles. [ABSTRACT FROM AUTHOR]

The reaction steps involved in the 5‐hydroxymethylfurfural to 2,5‐furandicarboxylic acid conversion by means of H2O2 were investigated employing a dedicated computational protocol based on density functional theory. The catalytic environment of choice was a molecular model representing a portion of the halloysite nanotube outer surface, functionalized by an organosilane, the 3‐aminopropyltriethoxysilane, whose amino group bonds one gold atom. At this stage of the investigation, the process was fully detailed in terms of the interactions between the reaction intermediates and the catalyst, and the reaction standard free energies. In addition, the energy barriers of the elementary steps involving the hydrogen migration from the adsorbed organic species to the gold atom were analyzed. On the basis of the interaction geometries, a certain distinction among the preferred reaction path can be inferred as a function of the net negative charge characterizing the catalyst outer surface. Since the inner surface of halloysite can represent the acid environment needed to obtain 5‐hydroxymethylfurfural through dehydration of fructose, the present study is framed in a wider research field where the possibility to consider functionalized halloysite as one‐pot reactor for the valorization of biomass is explored. [ABSTRACT FROM AUTHOR]

Na5YSi4O12 (NYSO) is demonstrated as a promising electrolyte with high ionic conductivity and low activation energy for practical use in solid Na-ion batteries. Solid-state NMR was employed to identify the six types of coordination of Na+ ions and migration pathway, which is vital to master working mechanism and enhance performance. The assignment of each sodium site is clearly determined from high-quality 23Na NMR spectra by the aid of Density Functional Theory calculation. Well-resolved 23Na exchangespectroscopy and electrochemical tracer exchange spectra provide the first experimental evidence to show the existence of ionic exchange between sodium at Na5 and Na6 sites, revealing that Na transport route is possibly along three-dimensional chain of open channel-Na4-open channel. Variable-temperature NMR relaxometry is developed to evaluate Na jump rates and self-diffusion coefficient to probe the sodium-ion dynamics in NYSO. Furthermore, NYSO works well as a dual ion conductor in Na and Li metal batteries with Na3V2(PO4)3 and LiFePO4 as cathodes, respectively. [ABSTRACT FROM AUTHOR]

One current research direction in proton-conducting solid oxide fuel cells (H–SOFCs) focuses on developing triple-phase conducting cathodes. By optimizing the cerium and indium ratio and adjusting the phase composition of barium ferrate cathode materials, improved power density is achieved in single cells with BaCe 0.21 Fe 0.64 In 0.15 O 3-δ (BCFI15) as the cathode, reaching a peak power density of 1473 mW cm−2 at 700 °C. Density functional theory calculations (DFT) further support that the incorporation of indium through doping effectively reduces the energy barrier for proton transition, thereby enhancing proton absorption capability and electrochemical reactivity. • Self-assembled composite cathodes are obtained by traditional sol-gel method. • Indium doping reduces proton migration barrier energy and improves cathode activation capacity. • Enhanced cell performance is achieved by regulating cathode chemical composition. [ABSTRACT FROM AUTHOR]

Na5YSi4O12 (NYSO) is demonstrated as a promising electrolyte with high ionic conductivity and low activation energy for practical use in solid Na-ion batteries. Solid-state NMR was employed to identify the six types of coordination of Na+ ions and migration pathway, which is vital to master working mechanism and enhance performance. The assignment of each sodium site is clearly determined from high-quality 23Na NMR spectra by the aid of Density Functional Theory calculation. Well-resolved 23Na exchangespectroscopy and electrochemical tracer exchange spectra provide the first experimental evidence to show the existence of ionic exchange between sodium at Na5 and Na6 sites, revealing that Na transport route is possibly along three-dimensional chain of open channel-Na4-open channel. Variable-temperature NMR relaxometry is developed to evaluate Na jump rates and self-diffusion coefficient to probe the sodium-ion dynamics in NYSO. Furthermore, NYSO works well as a dual ion conductor in Na and Li metal batteries with Na3V2(PO4)3 and LiFePO4 as cathodes, respectively. [ABSTRACT FROM AUTHOR]

Research on high‐efficiency and cost‐efficient catalysts for oxygen reduction reaction (ORR) is still a vital but challenging issue for commercializing metal–air batteries. Herein, a single‐molecule/atom hybrid catalyst is developed to boost the ORR, in which iron phthalocyanine molecules containing molecular Fe─N4 moieties couple with atomic Co─N4 sites on the surface of polyhedral carbon. Density functional theory calculations reveal that face‐to‐face laminated construction of Fe─N4 and Co─N4 in the hybrid catalyst can effectively modulate the electronic structure of active iron atoms and reduce the energy barrier of the rate‐determining step for ORR. As a result, this hybrid catalyst demonstrates excellent ORR performance, featuring a half‐wave potential of 0.904 V, a peak power density of 238.3 mW cm−2 for zinc–air battery, and outstanding electrocatalytic stability. This work offers a distinctive and robust molecular/atomic engineering approach to creating efficient electrocatalysts, advancing the fields of metal–air batteries. [ABSTRACT FROM AUTHOR]

Density functional theory calculations have been performed to compare the HCHO decomposition on Co3O4(110)-A and (110)-B terminations. The results showed that the energy barriers of the two C–H bond cleavages of HCHO on the (110)-A termination were lower than those on the (110)-B termination, suggesting that the (110)-A termination had stronger HCHO decomposition ability than the (110)-B termination. Electronic structures revealed that the stronger HCHO decomposition ability of the (110)-A termination might be ascribed to the strong covalent bond between HCHO and the (110)-A termination, as well as the higher d-band center of Co3+ ions on the (110)-A termination. Furthermore, we proposed that the preparation of Co3O4 under oxygen-rich growth conditions was beneficial to HCHO decomposition because the (110)-A termination was more stable under oxygen-rich conditions. [ABSTRACT FROM AUTHOR]

The mechanism of Y on H/H2 adsorption performance of Mg17Al12 were studied by the density functional theory. We obtained that for the Y-adsorbed systems, Y tended to occupy on the bridge site between adjacent Mg atoms. For the Y-substituted surfaces, Y atoms inclined to replace Mg atoms on the surfaces. We found that hydrogen (H/H2) absorption on the Mg17Al12(110) systems were improved by adding Y, the order of adsorption energy was as follows: clean Mg17Al12(110) > the Y-substituted surfaces > the Y-adsorbed surfaces. In addition, H2 molecules could dissociate on the Y-containing systems without barrier energy. Electronic properties showed that for H2 adsorption, the s states of atomic H mainly hybridized with the d states of Y. The formations of the Y-H bonds and the interactions between Y and H atoms could expound the mechanism for the promoted hydrogenation performance of the Y-containing surfaces. [ABSTRACT FROM AUTHOR]

The BH3‐mediated reduction of P‐stereogenic hydroxyalkylphosphine oxides was investigated by Density Functional Theory calculations. By combining theoretical approaches with experimental observations, we explored two mechanisms that account for its stereospecificity, implying an inversion of the configuration at the phosphorus atom. One mechanism proceeds through a cyclic intermediate in which the coordination of borane to the oxygen atoms lowers the BH3.THF‐attack barrier. However, the free energy barrier for this combined process is too high for a reaction feasible at room temperature. The calculations rather support a second mechanism that proceeds through from the same cyclic intermediate and the in‐situ formation of BH4− as reducing agent. [ABSTRACT FROM AUTHOR]

Sodium metal is regarded as an optimal anode material for high‐energy‐density sodium‐ion batteries (SIBs). However, during the processes of sodium deposition and stripping, the failure of the solid electrolyte interphase (SEI) film leads to the continuous accumulation of inactive sodium, thereby compromising the cycling reversibility of the battery. Here, a novel metal fluoride heterointerface layer is generated and constructed through in situ manipulation of the continuous reaction between TiF4 and metal Na. The reconstructed NaF/TiF3 interface layer, which tightly anchors the sodium metal, effectively suppresses the formation of sodium dendrites during the charge‐discharge process. The highly sodium‐philic TiF3 component exhibits strong binding with Na ions, while NaF reduces the Na+ diffusion energy barrier, significantly enhancing the reaction kinetics. Due to the successful artificial construction of this interface layer, the Na/TiF4 composite electrode demonstrates an exceptional ultra‐long cycling stability of 2370 h in symmetric cells (0.5 mAh cm−2). Density functional theory (DFT) calculations further validate the functionality of each component in the Na/TiF4 protective layer. When paired with NaNi1/3Fe1/3Mn1/3O2 cathode in a pouch cell, it exhibits stability up to 2000 cycles at current densities of 2 C and 4 C, with a maximum energy density output of 483.1 Wh kg−1 (power density: 320.8 W kg−1). [ABSTRACT FROM AUTHOR]

The sluggish kinetics of alkaline hydrogen evolution reaction (HER) hinders practical exploitation of water splitting. Catalysts, known as platinum single atoms (Pt‐SAs) anchored in Ni4Mo/Ni alloys on nickel foam (Pt SAs‐Ni4Mo/Ni@NF) with ultralow Pt mass loading (mPt = 0.3 wt.%) derived from self‐reconstruction, with boosted atomic utilization in alkaline HER are demonstrated. In situ characterizations confirm the leaching of Mo species during the self‐reconstruction of NiMoO4, which facilitates the anchoring of Pt‐SAs through the generation of atomic defects. Further, density functional theory (DFT) calculations indicate that the atomic defects can effectively capture Pt2+ in salt solution, aiding in the distribution of Pt‐SAs. Besides, theoretical results emphasize that Pt SAs‐Ni4Mo/Ni with unique Pt‐Ni interaction can accelerate the desorption of hydroxides in alkaline electrolytes during HER, as well as lower energy barriers for reaction steps. Pt SAs‐Ni4Mo/Ni@NF shows remarkable catalytic activity toward alkaline HER with a low overpotential of 17 mV (j = 10 mA cm−2), together with high atomic utilization of Pt (8.92 A mgPt−1 at 30 mV) and excellent durability. This work not only provides a scalable preparation for efficient and robust low‐Pt catalysts but also establishes in‐depth understanding of the synergistic interaction between Pt SAs and Ni‐Mo alloys in alkaline HER, which is likely to accelerate the development of water‐splitting technique. [ABSTRACT FROM AUTHOR]

Context: The theoretical study investigates the [3 + 2] cycloaddition (32CA) reactions between C, N-diphenyl nitrilimine with 2,3,4,5-tetraphenylcyclopentadienone and benzonitrile oxide with 2,3,4,5-tetraphenylcyclopentadienone. Nitrilimines and nitrile oxides are dipoles used in the synthesis of several heterocyclic compounds, including spiropyrazoline oxindoles and isoxazolines. The derivatives of these compounds are found with different biological activities, such as ion channel blockers, anti-inflammatory and anticancer agents as well as antimalarial. Conceptual density functional theory (CDFT) analysis, along with the activation energies of the 32CA reaction between C, N-diphenyl nitrilimine with 2,3,4,5-tetraphenylcyclopentadienone, demonstrates concordance with the empirical findings. The 32CA reaction is found to proceed through a very polar single-step asynchronous mechanism. While deductions from the activation energies of the 32CA reaction between benzonitrile oxide and 2,3,4,5-tetraphenylcyclopentadienone are found to lead to the experimental product, the parr function analysis could not explain the observed chemo- and regioselectivity. This 32CA reaction is also found to proceed through a one-step asynchronous mechanism, though with a non-polar character. The modulation of substituents positioned at the reactive sites of the reactants is found to influence the kinetics, thermodynamics, and CDFT parameters of the two 32CA reactions, consequently impacting the observed selectivities. Methods: The 32CA reactions between C, N-diphenyl nitrilimine with 2,3,4,5-tetraphenylcyclopentadienone and benzonitrile oxide with 2,3,4,5-tetraphenylcyclopentadienone have been explored theoretically using the density functional theory method at the hybrid ωB97X-D coupled with the split valence triple-ξ (TZ) basis set as implemented in the Gaussian 09. Solvent effects were taken into account by full optimization of the gas phase geometries through the polarizable continuum model developed within the self-consistent reaction field. [ABSTRACT FROM AUTHOR]

It is still a challenge to develop electrocatalyst for the efficient adsorption and conversion of organic molecule in aqueous media. Herein, a hetero‐interface structure based on CuO@Ni(OH)2 is rationally designed to enhance the performance of benzyl alcohol oxidation to benzoic acid. A high Faradaic efficiency of 99% and the yield of 3.09 mmol cm−2 h−1 are achieved at 1.70 V versus reversible hydrogen electrode, outperforming the previously reported electrocatalysts. Furthermore, a membrane‐free flow electrolyzer was assembled based on CuO@Ni(OH)2 hetero‐interface, exhibiting a much high yielding of benzoic acid (6.73 mmol cm−2 h−1) and hydrogen (0.35 L cm−2 h−1) with excellent stability. Both experimental data and density functional theory calculations verify that the electron is tend to accumulate at the hetero‐interface, thus accelerating the adsorption of reactant and intermediate and reducing the energy barrier of the conversion of benzyl alcohol to benzoic acid. [ABSTRACT FROM AUTHOR]

Oxygen vacancies (OV) in nonmetallic plasmonic photocatalysts can decrease the energy barrier for CO2 reduction, boosting C1 intermediate production for potential C2 formation. However, their susceptibility to oxidation weakens C1 intermediate adsorption. Herein we proposed a "photoelectron injection" strategy to safeguard OV in W18O49 by creating a W18O49/ZIS (W/Z) plasmonic photocatalyst. Moreover, photoelectrons contribute to the local multi‐electron environment of W18O49, enhancing the intrinsic excitation of its hot electrons with extended lifetimes, as confirmed by in situ XPS and femtosecond transient absorption analysis. Density functional theory calculations revealed that W/Z with OV enhances CO2 adsorption, activating *CO production, while reducing the energy barrier for *COH production (0.054 eV) and subsequent *CO−*COH coupling (0.574 eV). Successive hydrogenation revealed that the free energy for *CH2CH2 hydrogenation (0.108 eV) was lower than that for *CH2CH2 desorption for C2H4 production (0.277 eV), favouring C2H6 production. Consequently, W/Z achieves an efficient C2H6 activity of 653.6 μmol g−1 h−1 under visible light, with an exceptionally high selectivity of 90.6 %. This work offers a new strategy for the rational design of plasmonic photocatalysts with high selectivity for C2+ products. [ABSTRACT FROM AUTHOR]

The preparation of nanozymes with high specific activity is highly important for various applications. However, only a few nanozymes have specific activities comparable to natural enzymes. Herein, novel Pt-on-Rh hollow nanorods (PtRh HNRs) were developed, in which surface Pt exhibited adjustable dispersity and interior Rh served as the support. The optimized PtRh HNRs demonstrated high-performance peroxidase (POD)-like activity, with a specific activity as high as 1352 U mg−1, which was 3.86 times that of their monometallic Pt counterparts. Density functional theory (DFT) calculations illustrated that the presence of Rh decreased the energy barrier of the rate-determining step. When PtRh HNRs were used as nanozymes in the colorimetric detection of hydrogen peroxide (H2O2) and ascorbic acid (AA), the limits of detection (LODs) were as low as 9.97 μM and 0.039 μM, respectively. The current work highlights a facile and powerful strategy for manufacturing nanozymes with high specific activity and demonstrates that the prepared PtRh HNRs have the potential for analysis and determination. [ABSTRACT FROM AUTHOR]

[Display omitted] Engineering platinum-free catalysts for hydrogen evolution reaction (HER) with high activity and stability is essential for electrochemical hydrogen production. In this paper, we report the synthesis of cobalt-doped AlNi 3 /NiO (Co-AlNi 3 /NiO) electrode with three-dimensional nanoporous structure via chemical dealloying method. Density functional theory (DFT) calculations reveal that Co-AlNi 3 /NiO can accelerate water adsorption / dissociation and optimize adsorption–desorption energies of H* intermediates, thus improving the intrinsic HER activity. Both the introduction of Co and Al can efficiently ameliorate the electronic density around Ni sites of NiO and AlNi 3 , which can effectively reduce the energy barrier towards Volmer–Heyrovsky reaction and thus synergistically promote the hydrogen evolution. Benefiting from the large electrochemical active surface area, high electrical conductivity and electronic effect, the nanoporous Co-AlNi 3 /NiO catalyst exhibits remarkable HER activity with an overpotential of 73 mV at a current density of 10 mA cm−2 in alkaline condition, outperforming most of the reported non-precious metal catalysts. The nanoporous Co-AlNi 3 /NiO catalyst can operate continuously over 1000 h at high current densities with a robust stability. This work provides a new vision for the development of low-cost and efficient electrocatalysts for energy conversion applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Transition metal phosphides have been demonstrated to be promising non-noble catalysts for water splitting, yet their electrocatalytic performance is impeded by unfavorable free energies of adsorbed intermediates. The achievement of nanoscale modulation in morphology and electronic states is imperative for enhancing their intrinsic electrocatalytic activity. Herein, we propose a strategy to expedite the water splitting process over NiCoP/FeNiCoP hollow ellipsoids by modulating the electronic structure and d-band center. These unique phosphorus (P) vacancies-rich ellipsoids are synthesized through an ion-exchange reaction between uniform NiCo-nanoprisms and K 3 [Fe(CN) 6 ], followed by NaH 2 PO 2 -assisted phosphorization under N 2 atmosphere. Various characterizations reveals that the titled catalyst possesses high specific surface area, abundant porosity, and accessible inner surfaces, all of which are beneficial for efficient mass transfer and gas diffusion. Moreover, density functional theory (DFT) calculations further confirms that the NiCoP/FeNiCoP heterojunction associated with P vacancies regulate the electronic structures of d-electrons and p-electrons of Co and P atoms, respectively, resulting in a higher desorption efficiency of adsorbed H* intermediates with a lower energy barrier for water splitting. Due to the aforementioned advantages, the resultant NiCoP/FeNiCoP hollow ellipsoids exhibit remarkably low overpotentials of 45 and 266 mV for hydrogen and oxygen evolution reaction to achieve the current densities of 10 and 50 mA cm−2, respectively. This work not only reports the synthesis of a hollow double-shell structure of NiCoP/FeNiCoP but also introduces a novel strategy for constructing a multifunctional electrocatalyst for water splitting. [ABSTRACT FROM AUTHOR]

Thiophene is the organic sulfur with good thermal stability in carbon-based fuel, clarifying the conversion mechanism between thiophene and COS is beneficial for achieving in-situ sulfur fixation during CO2 gasification of carbon-based fuels, but the mechanism has rarely been reported. Therefore, calculations based on density functional theory were performed and 16 reaction paths were proposed in this research, clarifying the decomposition mechanism of thiophene and re-fixation mechanism of COS. The attachment of CO2 will lead to the destruction of the thiophene ring and the generation of COS, and CO2 adsorption is the rate-determined step, while the carbon atom that adjacent sulfur atom is the reaction active site. However, the energy barriers of CO2 addition reactions are lower than those of CO2 adsorption reactions, and the energy barrier of reactions occurring on the aliphatics are lower than that occurring on the aromatics. The combination of CO2 and thiophene will thermodynamically lead to the generation of COS and CO. Moreover, gaseous sulfur generated from thiophene decomposition will be converted mutually, while H2S will not be converted into COS. Furthermore, COS will be captured by char, forming solid organic sulfur. The re-fixation of COS will occur on aliphatic chains from the decomposition of aromatics. [ABSTRACT FROM AUTHOR]

Isothiazolones are important heterocyclics with pharmacological potency such as anti‐inflammatory, anticancer, antimicrobial, and robust biocidal (used in agrochemicals). This study seeks to provide mechanistic insight into the chemo‐ and regio‐selectivities of the [3 + 2] cycloaddition reaction of 5‐benzoyl‐3(2H)‐isothiazolone (A1) with two stable nitrile oxides, that is, mesitonitrile oxide (A2) and dichlorobenzonitrile oxide (A3) using M06‐2X hybrid density functional calculations coupled with the 6‐311G (d, p) basis sets. Mesitonitrile oxide A2 chemo‐selectively adds across the carbonyl of the benzyl group of A1 while dichloro benzonitrile oxide A3 preferentially adds across the ethylene center of A1. Derivatization of A1 with electron‐donating groups lowers the activation barriers by a very minute margin ranging from 0.1 to 0.5 kcal/mol whereas electron‐withdrawing groups significantly decrease the energetics of the reaction by a margin of 1.1 to 2.5 kcal/mol. Solvation with chloroform does not affect the selectivity of the reaction but tends to increase both activation and reaction energies of the various routes. Analysis of the Parr function on different reactive sites of A1 shows the addition of A2 via the atomic center with the largest Mullikan atomic spin densities. Substitution of the S‐heteroatom with C, O, or N does not affect the regioselectivity of the reaction but lowers the activation energies in the reaction of A1 with A3. The global electron density transfer (GEDT) values predict a polar reaction between A1 and A2 whereas the reaction of A1 and A3 is non‐polar. [ABSTRACT FROM AUTHOR]

It is important to tune the coordination configuration of dual‐atom catalyst (DAC), especially in the first coordination sphere, to render high intrinsic catalytic activities for oxygen reduction/evolution reactions (ORR/OER). Herein, a type of atomically dispersed and boron‐coordinated DAC structure, namely, FeN4B‐NiN4B dual sites, is reported. In this structure, the incorporation of boron into the first coordination sphere of FeN4/NiN4 atomic sites regulates its geometry and electronic structure by forming "Fe‐B‐N" and "Ni‐B‐N" bridges. The FeN4B‐NiN4B DAC exhibits much enhanced ORR and OER property compared to the FeN4‐NiN4 counterparts. Density functional theory calculations reveal that the boron‐induced charge transfer and asymmetric charge distributions of the central Fe/Ni atoms optimize the adsorption and desorption behavior of the ORR/OER intermediates and reduce the activation energy for the potential‐determining step. Zinc‐air batteries employing the FeN4B‐NiN4B cathode exhibit a high maximum power density (236.9 mW cm−2) and stable cyclability up to 1100 h. The result illustrates the pivotal role of the first‐coordination sphere of DACs in tuning the electrochemical energy conversion and storage activities. [ABSTRACT FROM AUTHOR]

One challenge confronting the Cu2O catalysts in the electrocatalysis of carbon dioxide reduction reaction (CO2RR) is the reduction of active Cu(I) species, resulting in low selectivity and quick deactivation. In this study, we for the first time introduce a bottom‐up growth of convex sphere with adjustable Cu(0)/Cu(I) interfaces (Cux@Cu2O convex spheres). Interestingly, the interfaces are dynamically modulated by varying hydrothermal time, thus regulating the conversion of C1 and C2 products. In particular, the 4 h hydrothermal treatment applied to Cu0.25@Cu2O convex sphere with the favorable Cu(0)/Cu(I) interface results in the highest selectivity for C2 products (90.5 %). In situ Fourier‐transform infrared spectroscopy measurements and density functional theory calculations reveal that the Cu(0)/Cu(I) interface lowers the energy barrier for the production of ethylene and ethanol while increasing the coverage of localized *CO adsorbate for increased dimerization. This work establishes a novel approach for transforming the state of valence‐sensitive electrocatalysts into high‐value energy‐related engineering products. [ABSTRACT FROM AUTHOR]

In this comprehensive study, we systematically investigated the mechanism of solubility and permeability of hydrogen on the surface and within the bulk structure of aluminum using density functional theory calculations. Our analysis involved determining the stable positions, diffusion energy barriers, and electronic properties of hydrogen atoms adsorbed on the aluminum (100) surface, as well as evaluating the solution energy and diffusion energy barrier of hydrogen within bulk aluminum. Our findings highlight that the OIS→TIS pathway exhibits the most probable diffusion of hydrogen atoms, characterized by the lowest barrier energy (E b = 0.138 eV). We also conducted calculations for various adsorption structures ranging from low to high coverage and determined the diffusion coefficient across a temperature range of 100–1000 K, comparing our results to experimental data. To accurately describe the interactions between surface and bulk atoms along with the adsorbate, we explored different placements of hydrogen atoms on the aluminum (100) surface. Our investigation revealed that increasing the depth of the hydrogen adsorption site from the surface for both TIS and OIS results in a decrease in the adsorption energy value. Moreover, we observed a more significant decrease in the diffusion coefficient at lower temperatures in the BS→HS transition, indicating a reduced tendency for hydrogen atoms to approach the aluminum (100) surface. The layer-dependent diffusion behavior demonstrated that as hydrogen atoms penetrate deeper into the surface, they encounter lower barrier energies and shorter diffusion lengths. Furthermore, the diffusion coefficient for hydrogen increases as it moves into the inner layers across all temperature ranges. • The mechanism of solubility and permeability of H atom on the surface and within the bulk structure of Al using DFT. • The OIS→TIS pathway shows the most probable diffusion of H atoms, characterized by the lowest barrier energy (E b = 0.138 eV). • Different placements of hydrogen atoms on the aluminum (100) surface were explored. • Increasing H adsorption depth from surface in TIS/OIS reduces adsorption energy. • As Hydrogen atoms penetrate deeper into the surface, they encounter lower barrier energies and shorter diffusion lengths. [ABSTRACT FROM AUTHOR]

We have studied the potential barriers for the penetration of atomic beryllium or boron inside the C60 fullerene by performing density functional theory (DFT) calculations with three variants for the exchange and correlation: B3LYP (hybrid functional), PW91, and PBE. Four principal trajectories to the inner part of C60 for the penetrating atom have been considered: through the center of six-member-carbon ring (hexagon), five-member-carbon ring (pentagon), and also through the center of the double C–C bond (D-bond) and the center of the single C–C bond (S-bond). Averaging over the three DFT variants yields the following barriers for beryllium penetrating inside a deformable fullerene: 3.2 eV (hexagon), 4.8 eV (S-bond), 5.3 eV (D-bond), 5.9 eV (pentagon). These barriers correspond to the slow and adiabatic penetration of Be, in contrast to the fast (non-adiabatic) penetration through the rigid cage of C60 resulting in 5.6 eV (hexagon), 16.3 eV (pentagon), 81.8 eV (S-bond), and 93.4 eV (D-bond). The potential barriers for the boron penetrating inside deformable/rigid C60 are 3.7/105.4 eV (D-bond), 4.0/86.8 eV (S-bond), 4.7/7.8 eV (hexagon), 6.8/14.0 eV (pentagon). [ABSTRACT FROM AUTHOR]

The initial Coulombic efficiency (ICE) for anode materials is usually one of important parameters for the energy density improvement of batteries. However, due to the lack of effective regulatory methods, the excellent ICE is usually difficult to achieve for SnS2 systems based on alloying/conversion mechanisms in Li‐storage process. Herein, a heterostructure constructed from SnS2 nanoflakes in situ anchored on graphene scroll (SnS2@GS) is engineered and fabricated involving a facile in situ sulfurization strategy. The SnS2@GS anode benefiting from 1D open and organized ion diffusion pathways, along with rapid charge transfer in the heterogeneous interfaces, achieves improved reversibility and kinetics. This material exhibits a remarkable specific capacity coupled with a high ICE (≈88%) while yielding robust rate properties. These exceptional lithium storage properties derive from improved conductivity and reduced energy barriers for Li‐ion migration in the heterostructures, as indicated by the density functional theory calculations. Besides, the full‐cell (LiFePO4//SnS2@GS) and the lithium‐ion capacitor based on SnS2@GS anode are assembled and deliver superior energy densities of 330 and 349 W h kg−1, respectively. This proposed approach is also popularized for the fabrication about other metal sulfide wrapped in graphene scroll to construct the anodes with remarkable properties. [ABSTRACT FROM AUTHOR]

It is the sluggish ion migration kinetics that seriously affects the practical performance of the magnesium ion batteries. Even though an electrode material design using rational interlayer engineering method could effectively solve this issue, the optimal interlayer distance remains undetermined. Herein, various VOPO4-based electrodes with expanded interlayer spacing were fabricated and the relationship between interlayer structure and battery performance was revealed. Electrochemical analysis combined with computations unveils the existence of an optimal interlayer structure, as inadequate expansion failed to fully utilization of the material performance, while excessive expansion degraded the electrode stability. Among them, the electrode with triethylene glycol (TEG) intercalation exhibited optimized performance, maintaining excellent cycling stability (191.3 mAh·g−1 after 800 cycles). Density functional theory (DFT) demonstrated the effectiveness and limitations to lowering the migration energy barrier by expanding the interlayer engineering. In addition, systematic mechanism research revealed the Mg2+ storage process: The stepwise shuttling of Mg2+ along the directions that lie in (001) plane triggers two pairs of redox processes, namely V5+/V4+ and V4+/V3+. This study, regulation of layer spacing to achieve the best integrated performance of electrodes, could deepen the understanding of interlayer engineering and guide the design of advanced multivalent-ion batteries. [ABSTRACT FROM AUTHOR]