Atomic Charges Research Articles

Advanced Charge Extended Hückel (CEH) Model and a Consistent Adaptive Minimal Basis Set for the Elements Z = 1-103.

The Charge Extended Hückel (CEH) model, initially introduced for adaptive atomic orbital (AO) basis set construction (J. Chem. Phys. 2023, 159, 164108), has been significantly revised to enhance accuracy and robustness, particularly in challenging electronic situations. This revision includes an extension toward f-elements, covering actinoids with their f-electrons in the valence space. We present a novel noniterative approximation for the electrostatic contribution to the effective Fock matrix, which substantially improves performance in polar or charged systems. Additionally, the training data set for elements Z = 1-103 has been expanded to encompass even more chemically diverse reference molecules as well as dipole moments and shell populations in addition to atomic charges. It includes a greater variety of "mindless" molecules (MLMs) as well as more complex electronic structures through open-shell and highly charged species. The revised method achieves mean absolute errors for atomic charges q of approximately 0.02 e- for randomly selected (mostly organic) molecules and 0.09 e- for MLMs, outperforming both classical charge models and established tight-binding methods. Furthermore, the revised CEH model has been validated through density functional theory calculations with the updated adaptive q-vSZP AO basis set on common thermochemical databases. Consistent with the extension of the CEH model, q-vSZP has also been variationally optimized and tested for elements Z = 58-71 and 87-103. The original versions of both CEH and q-vSZP are now considered deprecated.

Investigation of the Physical Attributes of Sr2GeCrO6, Sr2MgMoO6, Ba2MgMoO6, Ba2ZnMoO6, and Ba2HgWO6 Double Perovskite Oxides

A density functional theory‐based study on the physical properties of significant double perovskite oxides Sr2GeCrO6, Sr2MgMoO6, Ba2MgMoO6, Ba2ZnMoO6, and Ba2HgWO6 has been conducted using the Vienna Ab initio Simulation Package and WIEN2K code. Structural analysis reveals the simple cubic crystal structure of double perovskite oxides. Phonon properties indicate the dynamical stability of Sr2GeCrO6, Ba2MgMoO6, and Ba2ZnMoO6 compounds. The band structure analysis indicates the metallic character of Sr2GeCrO6. However, generalized gradient approximation of Perdew–Burke–Ernzerhof and modified Becke–Johnson both suggest the indirect semiconducting nature of Ba2MgMoO6 and Ba2ZnMoO6. The crystal orbital Hamilton population (–COHP) examination evidences the strongest bonding interactions of O–Ba in these perovskite oxides. Both Ba2MgMoO6 and Ba2ZnMoO6 compounds exhibit p‐type character, as indicated by the partial charge density distributions in the highest occupied molecular orbital and lowest unoccupied molecular orbital (LUMO) orbitals, which govern the band edges near Fermi level. LUMO orbitals are located on Mo and O atoms and are composed of heteronuclear s‐ and p‐type interactions. The investigation comprehensively analyzes calculated optoelectronic properties, including complex dielectric function, optical conductivity, loss function, refractive index, and so on. These parameters are examined in detail, offering profound insights into the materials’ optical and electronic characteristics.

Density functional study of neutral bimetallic copper–gold clusters and their hydrides

Bimetallic Cu m Au n clusters and their hydrides Cu m Au n H (m + n ≤ 6) have been studied systematically using DFT to investigate the adsorption capacity of the copper–gold clusters for hydrogen atoms and understand the evolution of structural, electronic, and energetic properties as a function of size and composition of the system. The stability and charge transfer from Cu to Au are maximised when the composition of Cu m Au n clusters is nearly balanced. In Cu m Au n clusters, Au atoms favour the surface/edges/vertices with negative charges and Cu atoms tend to be inside with positive charges, which is convenient for partial charge transfer from Cu to Au atoms and give rise to larger electrostatic interaction energy. The structure of Cu m Au n H hydride does not always come from that of the lowest energy bare Cu m Au n cluster plus an attached H atom. Among various possible adsorption sites, the top and bridge sites are energetically preferred for smaller Cu m Au n with m + n ≤ 4, while only the bridge site is preferred for bigger clusters (5 ≤ m + n ≤ 6). Electrons always transfer from bimetallic clusters to adsorbate H, however, there is no simple relationship between H chemisorption energy and the charge transfer. There exists an approximately linear correlation between the metal−H bond length and the metal−H stretching frequency.

Imaging Dihydrogen Bond-Driven Assembly of Borazine on Au(111).

Dihydrogen bondingis a peculiar type of attractive interaction occurring between a partially positively charged hydrogen atom and a partially negatively charged hydrogen atom. Borazine represents a prototypical molecule exhibiting dihydrogen bonding in both gas phase, as well as in its crystalline form. For borazine assemblies on solid surfaces, a direct observation and characterization of dihydrogen bonding has remained elusive, possibly due to an intricate interplay of substrate-molecule and intermolecular interactions. Here we present evidence of dihydrogen bonding occurring in borazine assemblies on a Au(111) surface. By means of low-temperature scanning tunneling microscopy, we unveiled distinct configurations, exhibiting single and double dihydrogen bonding. Density functional theory calculations elucidate the interplay between substrate adsorption and intermolecular interactions to stabilize the formation of borazine dimers on Au(111), being the building blocks for the formation of larger assemblies.

Computational detangling chalcogen elements substitutions associated ESDPT mechanism for oxazolinyl-substituted hydroxyfluorene derivatives

In view of the distinguished photochemical and photobiological characteristics of oxazolinyl-substituted hydroxyfluorene and its derivatives, herein, we mainly focus on probing into excited state behaviors of the novel 9,9-dimethyl-3,6-dihydroxy-2,7-bis(4,5-dihydro-4,4-dimethyl-2-oxazolyl) fluorene (Oxa-OH) derivatives. In light of the significant effects resulting from substituting oxygen elements, three Oxa-OH derivatives (i.e., Oxa-OO, Oxa-SS and Oxa-SeSe fluorophores) are considered in this work. For these three different fluorophores, we detangle the effects of atomic electronegativity and charge recombination related to oxygen elements in excited state double proton transfer (ESDPT) processes. Because of the low potential energy barriers, we confirm the ESDPT happens by the sequential type. Based on heterosubstituted Oxa-OS and Oxa-OSe compounds, we further verify the chalcogen atomic-electronegativity-regulated stepwise ESDPT mechanism. We sincerely wish our work could provide a theoretical reference for proving this novel mechanism of ESDPT experimentally.

Pyrazinamide-based Co(II), Ni(II) and Cu(II) complexes: DFT exploration of structure, reactivity properties and in silico ADMET profiles.

In this paper, we present a theoretical study on the complexation of Co(II), Ni(II), and Cu(II) with a pyrazinamide ligand (PZA), which plays an important role in the treatment of tuberculosis and has biological and pharmacological benefits. It is a hybrid organic/inorganic material involving coordination between a metal ion and PZA ligand containing different coordination sites. This allows it to have different binding modes with metal ions and, therefore, provides a versatile ability to coordinate with metals. This study aimed to optimize the structures of the [M(PZA)2Cl2] complexes using density functional theory (DFT) at the B3LYP/6-311G + (d,p) level and the M06-2X functional is a high-nonlocality functional of double the amount of nonlocal exchange 2X. Various properties, including geometrical parameters, natural bonding orbital (NBO) to determine atomic charges, HOMO-LUMO energies, electronic properties, reactivity (ELF, LOL), NCI-RDG, and molecular electrostatic potential (MEP) on the surfaces of key metal-PZA complexes were determined and described. The AIM method has also been used to examine the chemical bonds. Furthermore, an in silico analysis aiming to explore the ADMET profiles of the compounds under investigation revealed promising aqueous solubility, oral bioavailability and gastrointestinal absorption, in addition to favorable druglikeness non-toxic and non-carcinogenic characteristics. The DFT method was carried out using Gaussian 09 software and GaussView 5.0. Avogadro software was used to define the geometry of the complexes. The Multiwfn program was used to produce scatter plots of the reduced density gradient (RDG), non-covalent interactions (NCI), ELF, LOL, and to define the parameters selected for the topological analysis of the BCPs using Bader's AIM.

Sono-photo-Fenton action is improved by the addition of Passiflora edulis f. flavicarpa Degener (yellow passion fruit).

The improvement of the sono-photo-Fenton process at nearby neutral pH (~ 6.2) and high iron concentration (5mg L-1) by the addition of the juice of Passiflora edulis f.flavicarpa Degener (yellow passion fruit) on the degradation of imipenem in water is reported for the first time. Considering that the combination of sonochemistry with photo-Fenton takes advantage of the in situ sonogeneration of H2O2, the effects of frequency and acoustic power for the H2O2 accumulation were established initially. The sonication at 578kHz and 23.8 W favored the H2O2 generation. Using such frequency and power, the antibiotic was synergistically degraded by the sono-photo-Fenton system in distilled water, leading to ~ 90% removal at 120min of treatment. An atomic charge analysis showed that thioether, β-lactam ring, and carboxylic acid moieties on the imipenem structure were very prone to interactions with the HO• generated in the sono-photo-Fenton process. Indeed, the primary transformation products (TPs) came from the oxidation of the thioether, the opening of the β-lactam ring, and decarboxylations. Such TPs had a lower probability than imipenem to be active against bacteria. Besides, the addition of small amounts (2.5-10 µL) of the yellow passion fruit juice to the sono-photo-Fenton system significantly improved the pharmaceutical elimination. However, a juice excess (e.g., 100 µL) caused a detrimental effect due to competing effects by radicals. The juice of the yellow passion fruit induced analogous effects to citric acid (a commercial complexing agent) on the sono-photo-Fenton process. Indeed, the degradation of imipenem in simulated hospital wastewater by sono-photo-Fenton was improved by the yellow passion fruit juice (~ 38% at 60min), and it was similar to that with citric acid (~ 39% of removal at 60min). Thus, the commercial reagent can be replaced by a natural and low-cost complexing agent (e.g., yellow passion fruit juice or fruit wastes containing citric acid), as an enhancer of the sono-photo-Fenton process carried out at near-neutral pH and high iron concentration for degrading imipenem in water.

Optimizing energy conversion in direct carbon fuel cells based on brown coal char: Exploring the impacts of scandium substituted La0.6Sr0.4FeO3-δ anodes

Direct coal fuel cells (DCFCs) convert the chemical energy in coal directly into electricity, but their development has been hindered by insufficiently active anode materials and slow carbon oxidation kinetics. This study explores the use of scandium-doped B-site-deficient La0.6Sr0.4FeO3-δ (LSFScx, x = 0, 0.05, 0.10, 0.15) as anodes for brown coal char utilization in DCFCs. Our findings show that LSFScx (x≠0) anodes outperform the undoped LSF anode, with the LSFSc0.1 anode exhibiting the best performance. At 850 °C, the LSFSc0.1 anode achieves a maximum power density of 345.5 mW cm−2, a minimum polarization resistance of 0.18 Ω cm2, and an impressive discharge time of 13.23 h. These enhancements are attributed to scandium doping, which improves the three-phase reaction boundaries, enhances carbon oxidation through better oxide ion transport, and optimizes the electronic structure. Theoretical calculations indicate that scandium doping reduces the Bader charges of Fe atoms, weakens OFe bonds, lowers the oxygen vacancy formation energy, and maintains the electronic energy band structures. These results provide a new and effective pathway to improve the anode performance and efficiency of DCFCs, showcasing new possibilities for future research on scandium-based perovskite materials for DCFC applications.

Mechanistic insight into the catalytic activities of metallic sites on nitrogen-doped graphene quantum dots for CO2 hydrogenation

The origin of selectivity and activity of the CO2 hydrogenation reaction on single-atom catalysts composed of three adjacent 3d transition metals (Fe, Co, and Ni) supported on N-doped graphene quantum dots were systematically investigated and compared using density functional theory (DFT) calculations, natural bond orbital (NBO), and quantum theory of atoms in molecules (QTAIM) analysis. This study reveals that π-backbonding between the metal and CO2* does not occur and [CO2]δ+ species drive the reaction. The CO2* reacts with H2 via the Eley-Rideal (ER) mechanism by using the synergistic effects of the N site. The higher the partial positive charge on the C atom, the lower the Ea of the reaction. Subsequently, a tautomerization reaction, which is facilitated by hydrogen bonding, occurs and hydrogen is transferred to HCOO* resulting in the formation of CHOOH*. This study shows the selective formation of formic acid from CO2 is accessible on these SACs and Fe-SAC is the best one between these three catalysts. Although CO2 is more inert than formic acid the H2 molecule reacts with the adsorbed formic acid more difficult than the adsorbed CO2. It is because the hydrogenation of formic acid causes C-H bond formation resulting in failure of the coordinated O atom's octet and the unstable H2COOH* is formed. This step is the rate-determining step of HOCH2OH formation from CO2, with Ea of 1.94, 2.03, and 2.23 eV for Fe, Co, and Ni, respectively. Finally, the system undergoes another tautomerization reaction resulting in the formation of HOCH2OH (formaldehyde monohydrate).

The Impact of Pore Geometry on Frictional Properties of hBN and MoS2 Nanomaterials.

Two-dimensional (2D) nanomaterials hold significant promise for reducing energy consumption in water desalination. This study investigates the influence of pore size and shape on the slip behavior of saline water at the interface of two promising 2D nanomaterials: hexagonal boron nitride (hBN) and molybdenum disulfide (MoS2). Slip length, a key parameter governing fluid flow at the nanoscale, is highly dependent on interfacial properties. Here, we explore how the pore characteristics in these 2D nanomaterials can impact slip length, aiming to gain a fundamental understanding of the role of pore size and shape in optimizing desalination efficiency. We performed quantum mechanical calculations to compute the partial atomic charges on atoms in hBN and MoS2 containing pores. Our DFT calculations reveal a spatially varying charge distribution on these 2D nanomaterials with pores, which we then incorporate into molecular dynamic simulations to elucidate their influence on the 2D nanomaterial-water interface. Our results reveal a significant impact of pore size on friction for nanomaterials containing hexagonal pores, while pore size had no effect on nanomaterials containing triangular pores. Moreover, friction increases with pores in both materials. This research contributes to the development of efficient and energy-saving desalination technologies through the manipulation of interfacial properties in 2D nanomaterials.

Density Functional Theory Study on Screening and Key Metrics for Non-metallic Oxygen Reduction Catalysts.

This study systematically investigates the oxygen reduction reaction (ORR) catalytic activity of graphene doped with various non-metallic impurities. The non-metal elements include boron (B), silicon (Si), nitrogen (N), phosphorus (P), arsenic (As), oxygen (O), sulfur (S), selenium (Se), tellurium (Te), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). We found that adsorbates tend to adsorb on positively charged impurity atoms. We identified several substrates with good catalytic activity, all of which have an ORR overpotential of around 0.6 V. We further verified the thermodynamic stability of these substrates and found them to be very stable. We summarized the optimal adsorption energies for ORR intermediates O2H, O, and OH to be -1.9, -3.4, and -2.4 eV, respectively, and validated their reasonableness. Finally, we used simple linear functions to fit the relationship between the adsorption energies of O2H, O, and OH and the charge and magnetic moment of the adsorption site atoms. This model can roughly predict the ORR catalytic activity of doped graphene, facilitating the faster screening of excellent ORR catalysts.

Density functional theory to decrypt metal-organic framework-A review

Metal-organic frameworks (MOFs), which are extremely crystalline but have molecular structures, exist at the interface between molecules and materials. The interwoven chemistry of MOFs allows for the construction of a virtually unlimited variety of materials, some of which can be employed in place of porous materials that have previously been used for many applications like gas storage, drug delivery, and so on. Due to the exponential development in the number of MOFs and their potential uses, it is impractical to test them for every prospective usage when novel MOFs are synthesised. Herein lies the significance of computational investigations. The major technique in computational investigations on metal–organic frameworks is the density-functional theory (DFT), which consistently yields atomic charges, electronic energies, molecular geometries, excited states vibrational analyses, NMR spectra, and so on. DFT can decipher the complete MOF clan. This review investigates MOFs and their electrical and optical properties, which can be employed in a variety of applications including catalysis, photoluminescence, absorption, separations, screening, and sensing of various materials utilising DFT and its tools.

STRUCTURE-ACTIVITY RELATIONSHIP OF PSYCHOACTIVE CANNABINOIDS: A CHEMOMETRIC EXPERIMENT FOR UNDERGRADUATE AND POSTGRADUATE STUDENTS IN CHEMICAL EDUCATION

Undergraduate and postgraduate Chemistry Education students had to develop the experiment in four (4) stages. Twenty-two (22) cannabinoids (Δ9-THC and derivatives) with different degrees of psychoactivity, previously scrutinized by our research group with the approaches: molecular electrostatic potential (MEP) and interaction with the CB1 receptor (CARDOSO-FILHO et al., 2004), are investigated through Chemometrics. Exploratory Analysis: Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). E Classification Methods: K-Nearest Neighbor (KNN) method, Soft Independent Modeling Class Analogy (SIMCA) method, and Stepwise Discriminant Analysis (SDA) were employed to reduce the dimensionality of the data matrix and investigate which descriptors are responsible for the classification between the most active cannabinoids (mac), pKi ≥ 6.72, and the least active cannabinoids (lac), pKi < 6.72, according to the hypothesis previously reported (Cardoso-Filho et al., 2024). The investigation with PCA, HCA, KNN, SIMCA, and SDA showed that the descriptors LUMO+1 energy, Geary autocorrelation of lag 6 weighted by van der Waals volumes (GATS6V), hydration energy (EH), atomic charge on the atom of C4 (qC4), and molecular representation of structure based on the electron diffraction, code of signal 3, unweighted (MOR03u) are responsible for separating cannabinoids according to their degrees of psychoactivity. The insights accumulated and the models built in the research – PCA chemometric model, HCA chemometric model, KNN chemometric model, SIMCA chemometric model, and SDA chemometric model – will be able to support the design of new potentially psychoactive Δ9-THC derivatives.

Variational Hirshfeld Partitioning: General Framework and the Additive Variational Hirshfeld Partitioning Method.

We introduce the general mathematical framework of variational Hirshfeld partitioning, wherein the best possible approximation to a molecule's electron density is obtained by minimizing the f-divergence between the molecular density and a non-negative linear combination of (normalized) basis functions. This framework subsumes several existing methods that variationally optimize their pro-atoms, like (Gaussian) iterative stockholder analysis (ISA and GISA) and minimal basis iterative stockholder partitioning (MBIS), and provides a solid foundation for developing mathematically rigorous partitioning schemes. In this paper, we delve into the mathematical underpinnings of Hirshfeld-inspired partitioning schemes and show that among all the valid f-divergence measures only the extended Kullback-Leibler is a suitable choice. This led us to develop a novel partitioning scheme, called additive variational Hirshfeld (AVH), which constructs the pro-molecular density as a convex linear combination of the densities from selected states of isolated atoms and atomic ions. The AVH method is size-consistent with a unique solution and provides a straightforward approach for adding constraints for fragment properties. It also results in an intuitively appealing valence-bond-like decomposition of the molecular density as a weighted average of the densities of the atomic states in the molecule; that is, the AVH atomic density is a minimal deformation of the corresponding isolated atomic reference state's density. Compared to other variational Hirshfeld variants, our numerical results show that AVH yields chemically interpretable and sensible atomic charges that are not excessively large and demonstrate computational robustness.

Stimuli-Triggered Diffusion Dynamics in Single-Junction Electrode for Enhanced Supercapacitor Performance: Insights into the Carrier Relaxation and Charge Transfer Kinetics.

Study of external triggers add new chemistry to energy storage research by virtue of controlling diffusion and charge transfer dynamics. Herein, we have chosen a model system, Ag2S-BiVO4 (Ag2S-BVO), for examining the diffusion dynamics upon light illumination using electrochemical and carrier relaxation studies. Favorable band alignments in the single-junction electrode lead to optimized carrier movement across the interfaces, developing a partial positive charge on the electrode, thereby enhancing the mass-transport of electrolyte ions toward the active electrode for efficient charge storage. Synergistic coupling across the heterojunction provides a high areal capacity of 338 mF cm-2 at 0.5 mA cm-2 under light illumination by facilitating the dominant diffusion characteristics within system. In addition, the Ag2S-BVO-based asymmetric supercapacitor exhibits an areal energy density of 32 mWh cm-2 @ 700 mW cm-2 under illumination. This study provides a strategy to tune the capacitive and diffusion contributions for high-performance light-sensitive supercapacitor devices.

Anti-inflammatory and antioxidant activity, toxicity prediction, computational investigation, and molecular docking studies of 2-thiophenecarbonitrile

Density Functional Theory (DFT) and Molecular docking are pivotal computational techniques in modern chemistry and drug design. This work investigates the electronic structure and reactivity of 2-thiophenecarbonitrile (2TCN) with an emphasis on important factors such as HOMO-LUMO energy gap, MEP, Mulliken atomic charges, natural population analysis, and Mutiwfn (ELF, LOL, ALIE, and RDG) analysis. The MEP and FMO studies were calculated in various solvents like acetonitrile, water, gas, and methanol. The anti-inflammatory and antioxidant investigations revealed substantial activities by 2TCN. Additionally, molecular docking studies are performed to elucidate the binding interaction between the compound and target proteins, providing insights into its potential therapeutic mechanisms. The results demonstrate the binding energies, interaction residues, and the most favorable docking poses. This approach underscores the integration of theoretical and computational methods in advancing molecule design and therapeutic discovery.

On the similar spectral manifestations of protonic and hydridic hydrogen bonds despite their different origin

Previously studied complexes with protonic and hydridic hydrogen bonds exhibit significant similarities. The present study provides a detailed investigation of the structure, stabilization, electronic properties, and spectral characteristics of protonic and hydridic hydrogen bonds using low-temperature infrared (IR) spectroscopy and computational methods. Complexes of pentafluorobenzene with ammonia (C₆F₅H⋯NH₃) and triethylgermane with trifluoroiodomethane (Et₃GeH⋯ICF₃) were analyzed using both experimental and computational tools. Additionally, 30 complexes with protonic hydrogen bonds and 30 complexes with hydridic hydrogen bonds were studied computationally. Our findings reveal that, despite the opposite atomic charges on the hydrogens in these hydrogen bonds, and consequently the opposite directions of electron transfer in protonic and hydridic hydrogen bonds, their spectral manifestations - specifically, the red shifts in the X–H stretching frequency and the increase in intensity - are remarkably similar. The study also discusses the limitations of the current IUPAC definition of hydrogen bonding in covering both types of H-bonds and suggests a way to overcome these limitations.

Molecular properties of a triazole-Ce(III) complex with antioxidant activity: structure, spectroscopy, and relationships with related derivatives. Influence of the ligands in the complex.

A novel Ce(III) complex with the triazole ligand 2b, which presents four H-bonded sites with amino acids of the MMP-2 receptor, was synthesized. The experimental IR and Raman spectra of this Ce(III) complex were well-interpreted based on their comparison to the theoretical scaled spectra using the scaling equations determined by two procedures and four density functional theory (DFT) levels. Therefore, the structure predicted for the synthesized Ce(III) complex was clearly characterized and confirmed. The potential antioxidant action of this complex was compared with the analogous La(III) complex, and it was found that the coordination of ligand 2b with Ce(III) improves the ligand's ability to participate in single-electron transfer (SET), as observed in the ABTS·+ assay, and this complex seems to scavenge the stable radical much more actively compared to its La(III) counterpart. Additionally, interactions with potassium superoxide and sodium hypochlorite indicate a high pro-oxidant behavior of the complex. The effects of different ligands on the geometric parameters, atomic charges, and molecular properties of the Ce(III) complex were analyzed at four DFT levels, and several relationships were clearly established. These relationships can facilitate the selection of new ligands with improved properties in the design of novel lanthanide-triazole carboxylate complexes with promising biological activity. The ligand size increase in the complexes facilitates the electronic transfer of negative charge, and the low HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital) energy gap indicates a large reactivity and low energy for their excitation.

Polyoxometalates-Mediated Selectivity in Pt Single-Atoms on Ceria for Environmental Catalysis.

Optimizing the reactivity and selectivity of single-atom catalysts (SACs) remains a crucial yet challenging issue in heterogeneous catalysis. This study demonstrates selective catalysis facilitated by a polyoxometalates-mediated electronic interaction (PMEI) in a Pt single-atom catalyst supported on CeO2 modified with Keggin-type phosphotungstate acid (HPW), labeled as Pt1/CeO2-HPW. The PMEI effect originates from the unique arrangement of isolated Pt atoms and HPW clusters on the CeO2 support. Electrons are transferred from the ceria support to the electrophilic tungsten in HPW clusters, and subsequently, Pt atoms donate electrons to the now electron-deficient ceria. This phenomenon enhances the positive charge of Pt atoms, moderating O2 activation and limiting lattice oxygen mobility compared to the conventional Pt1/CeO2 catalyst. The resulting electronic structure of Pt combined with the strong and local acidic environment of HPW on Pt1/CeO2-HPW leads to improved efficiency and N2 selectivity in the degradation of NH3 and NO, as well as increased CO2 yield when inputting volatile organic compounds. This study sheds the light on the design of SACs with balanced reactivity and selectivity for environmental catalysis.

Polyoxometalates‐Mediated Selectivity in Pt Single‐Atoms on Ceria for Environmental Catalysis

AbstractOptimizing the reactivity and selectivity of single‐atom catalysts (SACs) remains a crucial yet challenging issue in heterogeneous catalysis. This study demonstrates selective catalysis facilitated by a polyoxometalates‐mediated electronic interaction (PMEI) in a Pt single‐atom catalyst supported on CeO2 modified with Keggin‐type phosphotungstate acid (HPW), labeled as Pt1/CeO2‐HPW. The PMEI effect originates from the unique arrangement of isolated Pt atoms and HPW clusters on the CeO2 support. Electrons are transferred from the ceria support to the electrophilic tungsten in HPW clusters, and subsequently, Pt atoms donate electrons to the now electron‐deficient ceria. This phenomenon enhances the positive charge of Pt atoms, moderating O2 activation and limiting lattice oxygen mobility compared to the conventional Pt1/CeO2 catalyst. The resulting electronic structure of Pt combined with the strong and local acidic environment of HPW on Pt1/CeO2‐HPW leads to improved efficiency and N2 selectivity in the degradation of NH3 and NO, as well as increased CO2 yield when inputting volatile organic compounds. This study sheds the light on the design of SACs with balanced reactivity and selectivity for environmental catalysis.