The Journal of Physical Chemistry C最新文献

Mayer bond order (MBO) allows partitioning of total charge in a given system into overlap population components which can be interpreted as charges shared among atoms and retained by them through atomic orbitals. In this work, we formulate a spatial distribution of these partitioned components, rendering a breakup of the total charge density into individual densities of charges shared between all the available pairs of atoms, as well as charges exclusively retained by each of the atoms themselves. The spatial density of the interatomic MBOs in particular facilitates an unbiased physical description of electrons shared between two atoms, thus essentially constituting a plottable representation of a covalent bond, obtained without inducing any explicit localization of electrons between atoms, which otherwise is an inherent source of bias. We demonstrate the proposed formulation in the basis of Wannierized atomic orbitals constructed from first principles, in a few representative varieties of systems with varying degrees of interatomic hybridization, including scenarios of multicentered bonds in molecules, to metavalent bonding in periodic systems introduced and debated in the past few years. Pertinently, in GeTe, we find two electrons (2e) contributed by collinear p orbitals in each of the three Ge–Te–Ge(Te–Ge–Te) segments passing through Te(Ge), constituting a compact distribution of 2e over the 3 atom segments (3c), along with the relatively inert s electrons maintaining a spherical shape, to facilitate near completion of subshell filling of both the atoms, thus supporting the prevalence of 3c-2e metavalent bonding in the class of narrow band gap rock-salt structures.

We investigated the mechanisms underlying strong metal-support interactions in CO oxidation using model systems where noble metal crystals support reducible, monolayer-thick CoO_x films. The effect of the Co oxidation state, film thickness, and substrate identity were studied in varying reaction conditions using ambient pressure X-ray photoelectron spectroscopy. At low O₂ pressures, the same oxide phase forms on both Pt(111) and Au(111) surfaces. But when heated at higher O₂ pressures, the oxide phase depends on the substrate. We found that CoO_x/Pt is more active for the CO oxidation reaction than CoO_x/Au, even when both surfaces stabilize the same oxide phase. DFT calculations on these and related noble-metal-supported CoO_x films reveal an SMSI-induced reactivity enhancement that strongly depends on the oxide film thickness and which is mediated by charge transfer between the metal and oxide. Charge transfer is also found to correlate with the reaction energy and activation barrier for CO oxidation. This effect was found to be greatest for oxide films on Pt, decreasing on other noble metal supports in the order Pt > Pd > Au > Ag, in agreement with the experiments. The role of charge transfer in the activation barriers and reaction energies provides insight into the nature of SMSI-induced catalytic activity, and suggests that the noble metal work function can serve as an indicator for the strength of SMSI effects.

Machine-learning-accelerated discovery of monoclinic BeA₂X₄ (A = Al, Ga, In; X = Se, Te) yields six infrared-absorbing chalcogenides with thickness-tunable absorptance. A 3814-compound prototype library was stability- and gap-screened to 1268 candidates; XGBoost (R² = 0.939, MAE = 0.241 eV) nominated BeAl₂Se₄, BeGa₂Se₄, BeIn₂Se₄, BeAl₂Te₄, BeGa₂Te₄, and BeIn₂Te₄. Hybrid-DFT (HSE06) and 10,000 fs ab initio molecular dynamics (AIMD) simulations at 300 K confirm the monoclinic Pm structure with thermal robustness. BeGa₂Se₄ exhibits the highest Vickers hardness (1.59 GPa), and BeAl₂Te₄ exhibits the largest Poisson ratio (0.44). The strong anisotropic absorption spans 0.5–1.6 eV, peaking at 1.21 × 10⁵ cm^–1 (BeIn₂Se₄) and 1.16 × 10⁵ cm^–1 (BeAl₂Te₄, 0.5–1 eV). Absorptance scales linearly with thickness: 0.747 (500 nm BeAl₂Se₄), 0.726 (450 nm BeGa₂Se₄), and 0.650 (300 nm BeIn₂Se₄), defining a 300–500 nm design window that balances absorption gain against carrier transport loss. Direct band gaps eliminate phonon bottlenecks, while their systematic narrowing with A/X cation radii enables continuous spectral tuning across the near- to mid-infrared. The quantitative structure–absorption map provides experimentally accessible guidelines for next-generation infrared absorption coatings and photodetector absorber layers.

Hydroxide catalysis bonding (HCB), also known as silicate bonding, is widely employed to join oxide materials in precision optical instruments due to its ability to form strong, thin bonds under mild conditions. The chemical reactions underlying HCB, including hydration, polymerization, and dehydration, have been relatively well understood, yet the atomic-scale chemical structure of the bonded interface after water removal remains unexplored, limiting a complete mechanistic understanding of HCB. In this study, sodium silicate (mSiO₂:Na₂O) was employed as the HCB layer, with sapphire chosen as a model substrate to resolve the interfacial bonding mechanism. We combined ab initio molecular dynamics (AIMD) simulations and experimental validation to elucidate the interfacial chemistry. AIMD simulations revealed atomic-level processes including interfacial Al–O partial amorphization, Na migration, and formation of Al–O–Si and Al–O–Na linkages. The simulations predicted that the optimal bonding strength appears at a SiO₂/Na₂O molar ratio (m) of approximately 2, a result validated by bonding tests and corroborated by ATR-IR spectroscopy showing Al–O–Si bond formation at the interface. These results establish a direct relationship between SiO₂/Na₂O molar ratio, interfacial atomic structure, and mechanical strength, providing valuable guidance for designing robust HCB technologies.

Interatomic potentials (IPs) with wide elemental coverage and high accuracy are powerful tools for high-throughput materials discovery. While the past few years witnessed the development of multiple new universal IPs that cover wide ranges of the periodic table, their applicability to target chemical systems should be carefully investigated. We benchmark several universal IPs using equilibrium zeolite structures as testbeds by evaluating geometric parameters, energies, and relative stability. We select a diverse set of universal IPs encompassing two major categories: (i) universal analytic IPs, including GFN-FF, UFF, and Dreiding; (ii) pretrained universal machine learning IPs (MLIPs), comprising CHGNet, ORB-v3, MatterSim, eSEN-30M-OAM, PFP-v7, and EquiformerV2-lE4-lF100-S2EFS-OC22. We compare them with established tailor-made IPs, SLC, ClayFF, and BSFF using experimental data and density functional theory (DFT) calculations with dispersion correction as the reference. The tested zeolite structures comprise pure silica frameworks and aluminosilicates containing copper species, potassium, and an organic cation. We found that GFN-FF is the best among the tested universal analytic IPs, but its good performance is limited in silica zeolites without highly strained rings. Some universal MLIPs achieve the energies with a root mean squared error between MLIP and DFT energies below a previously tailor-made MLIP. Among the universal MLIPs, the eSEN-30M-OAM model outperformed the other universal IPs in predicting structures and energies close to experiments and DFT across all zeolite structures studied. These findings show that the modern pretrained universal MLIPs are practical tools in replacing high-throughput DFT calculations against equilibrium zeolite structures, although they inherit the inherent errors of DFT.

Heterogeneous catalysis involves a complex interplay of adsorption, charge transfer, and catalyst restructuring at solid–gas or solid–liquid interfaces. While first-principles methods such as KS-DFT and AIMD accurately describe chemisorbed species, they struggle to capture weakly bound or dynamic molecules subject to thermal fluctuations. Continuum models provide macroscopic insight into electrostatics and transport but often neglect the interfacial molecular structure, especially within the Stern layer. The challenge is even greater at gas–solid interfaces, where the gas phase is typically ignored, giving rise to a long-standing pressure gap between theory and experiment. This Perspective advocates a statistical-mechanical description of interfacial species using classical density functional theory (cDFT), in which physisorption and gas/liquid-phase inhomogeneity near catalytic surfaces are represented by molecular density distributions rather than fixed atomic configurations. More importantly, we emphasize the necessity of integrating KS-DFT with such microenvironmental models and propose several potential strategies for coupling electronic-structure calculations with continuum and statistical-mechanical approaches. By merging first-principles, continuum, and statistical-mechanical approaches within open-system, physics-informed frameworks, it becomes possible to bridge electrochemical and thermocatalytic regimes─from localized chemisorption to diffuse physisorption─and reveal the true complexity of catalytic interfaces.