Rational Design of Dual-Atom Catalysts for Electrochemical CO Reduction to C and C Products with High Activity and Selectivity: A Density Functional Theory Study.

Carbon dioxide (CO) electroreduction using renewable energy provides a sustainable solution to mitigate greenhouse effects and achieve carbon neutrality. Developing high-performance electrocatalysts for the CO reduction reaction (CORR) is key to promoting such a technology. Herein, we systematically explored the CORR catalytic activity of 325 dual-metal-site catalysts (DMSCs) through density functional theory (DFT) calculations.

Enhanced CO electrochemical reduction on single-atom catalysts with optimized environmental, central and axial chemical ambient.

Single-atom catalysts (SACs) have received significant research interests for electrocatalytic CO reduction reaction (CORR) to produce valuable chemicals. Designing optimal SACs for CORR is a great challenge because of the strong scaling relationship among the many carbon-containing intermediates. In this study, we designed high-performance SACs, breaking the scaling relationship through changing environmental nonmetals, central atoms and axial nonmetals together via a series of density functional theory (DFT) calculations.

Comparative study of the reductive decomposition reaction of ethylene carbonate in lithium battery electrolyte: a ReaxFF molecular dynamics study.

Electrolyte decomposition and subsequent solid electrolyte interphase (SEI) are considered to be the primary cause of degradation of lithium batteries. We investigate the multiple factors that can affect the reductive decomposition pathways of ethylene carbonate (EC) and SEI formation using reactive molecular dynamics. Our simulations reveal the effects of lithium concentration, simulation temperature, and the imposition of external electric field on the decomposition reaction and pathways, respectively.

Mechanisms of microexplosion-accelerated pyrolysis and oxidation of lithium-containing droplets: an atomistic perspective.

Microexplosion has been extensively studied in the context of fuel spray and droplet evaporation in engines, while its existence, impact and atomistic insight have rarely been explored in the context of flame synthesis of nanoparticles. In this study, reactive force-field molecular dynamics simulations are performed to elucidate the mechanisms of pyrolysis and oxidation of an isolated lithium nitrate nanodroplet. During the pyrolysis process, the nucleation and growth of a bubble are observed inside the droplet, which should be ascribed to the release of nitrogen and oxygen gases from the decomposition of lithium nitrate, ultimately leading to rapid droplet fragmentation (microexplosion).

Effects of Electric Field on Chemical Looping Combustion: A DFT Study of CO Oxidation on CuO (111) Surface.

Chemical looping combustion (CLC) is a promising and novel technology for carbon dioxide (CO) capture with a relatively low energy consumption and cost. CuO, one of the most attractive oxygen carriers (OCs) for carbon dioxide (CO) oxidation, suffers from sintering and agglomeration during the reduction process. Applying an electric field (EF) may promote the CO oxidation process on the CuO surface, which could mitigate sintering and agglomeration by decreasing operating temperatures with negligible combustion efficiency loss.

Defect-Driven Efficient Selective CO Hydrogenation with Mo-Based Clusters.

Synthetic fuels produced from CO show promise in combating climate change. The reverse water gas shift (RWGS) reaction is the key to opening the CO molecule, and CO serves as a versatile intermediate for creating various hydrocarbons. Mo-based catalysts are of great interest for RWGS reactions featured for their stability and strong metal-oxygen interactions.

Theoretical exploration on the performance of single and dual-atom Cu catalysts on the CO electroreduction process: a DFT study.

Carbon dioxide (CO) electroreduction by metal-nitrogen-doped carbon (MNC) catalysts is a promising and efficient method to mitigate global warming by converting CO molecules to value-added chemicals. In this research, we systematically studied the behaviours of single and dual-atom Cu catalysts during the CO electroreduction process using density functional theory (DFT) calculations. Two structures, , CuNC-4-pyridine and CuCuNC-4a, were found to be beneficial for C chemical generation with relatively high stabilities.

Hetero-Diels-Alder Reaction between Singlet Oxygen and Anthracene Drives Integrative Cage Self-Sorting.

A ZnL pseudocube containing anthracene-centered ligands, a ZnL' tetrahedron with a similar side length as the cube, and a trigonal prism ZnLL' were formed in equilibrium from a common set of subcomponents. Hetero-Diels-Alder reaction with photogenerated singlet oxygen transformed the anthracene-containing "L" ligands into endoperoxide "L" ones and ultimately drove the integrative self-sorting to form the trigonal prismatic cage ZnLL' exclusively. This ZnLL' structure lost dioxygen in a retro-Diels-Alder reaction after heating, which resulted in reversion to the initial ZnL + ZnL' ⇌ 2 × ZnLL' equilibrating system.

Molecular dynamics study on evaporation of metal nitrate-containing nanodroplets in flame spray pyrolysis.

Flame spray pyrolysis (FSP) provides an advantageous synthetic route for LiNiCoMnO (NCM) materials, which are one of the most practical and promising cathode materials for Li-ion batteries. However, a detailed understanding of the NCM nanoparticle formation mechanisms through FSP is lacking. To shed light on the evaporation of NCM precursor droplets in FSP, in this work, we employ classical molecular dynamics (MD) simulations to explore the dynamic evaporation process of nanodroplets composed of metal nitrates (including LiNO, Ni(NO), Co(NO), and Mn(NO) as solutes) and water (as solvent) from a microscopic point of view.

Fabrication of Z-scheme BiOI/g-CN heterojunction modified by carbon quantum dots for synchronous photocatalytic removal of Cr (Ⅵ) and organic pollutants.

Chromium(VI) (Cr(VI)), a highly toxic metal ion, generally co-exists with organic pollutants in industrial effluents. The clean and effective technology for water purification is an imperative issue but still a challenging task. A series of BiOI/g-CN (BOI/CN) composites modified by lignin-derived carbon quantum dots (CQDs) were fabricated by hydrothermal method and applied for synchronous photocatalytic removal of Cr (Ⅵ) and levofloxacin (LEV).

Unified lattice Boltzmann method with improved schemes for multiphase flow simulation: Application to droplet dynamics under realistic conditions.

As a powerful mesoscale approach, the lattice Boltzmann method (LBM) has been widely used for the numerical study of complex multiphase flows. Recently, Luo et al. [Philos.

Exploring Complex Reaction Networks Using Neural Network-Based Molecular Dynamics Simulation.

molecular dynamics (AIMD) is an established method for revealing the reactive dynamics of complex systems. However, the high computational cost of AIMD restricts the explorable length and time scales. Here, we develop a fundamentally different approach using molecular dynamics simulations powered by a neural network potential to investigate complex reaction networks.

On the determination of Lennard-Jones parameters for polyatomic molecules.

Characterizing the key length and energy scales of intermolecular interactions, Lennard-Jones parameters, , collision diameter and well depth, are prerequisites for predicting transport properties and rate constants of chemical species in dilute gases. Due to anisotropy in molecular structures, Lennard-Jones parameters of many polyatomic molecules are only empirically estimated or even undetermined. This study focuses on determining the effective Lennard-Jones parameters between a polyatomic molecule and a bath gas molecule from interatomic interactions.

How sodium chloride extends lifetime of bulk nanobubbles in water.

We present a molecular dynamics simulation study on the effects of sodium chloride addition on stability of a nitrogen bulk nanobubble in water. We find that the lifetime of the bulk nanobubble is extended in the presence of NaCl and reveal the underlying mechanisms. We do not observe spontaneous accumulation or specific arrangement of ions/charges around the nanobubble.

Droplet evaporation in finite-size systems: Theoretical analysis and mesoscopic modeling.

The classical D^{2}-Law states that the square of the droplet diameter decreases linearly with time during its evaporation process, i.e., D^{2}(t)=D_{0}^{2}-Kt, where D_{0} is the droplet initial diameter and K is the evaporation constant.

Improved three-dimensional thermal multiphase lattice Boltzmann model for liquid-vapor phase change.

Modeling liquid-vapor phase change using the lattice Boltzmann (LB) method has attracted significant attention in recent years. In this paper, we propose an improved three-dimensional thermal multiphase LB model for simulating liquid-vapor phase change. The proposed model has the following features.

Small-scale fluctuation and scaling law of mixing in three-dimensional rotating turbulent Rayleigh-Taylor instability.

The effect of rotation on small-scale characteristics and scaling law in the mixing zone of the three-dimensional turbulent Rayleigh-Taylor instability (RTI) is investigated by the lattice Boltzmann method at small Atwood number. The mixing zone width h(t), the root mean square of small scale fluctuation, the spectra, and the structure functions are obtained to analyze the rotating effect. We mainly focus on the process of the development of plumes and discuss the physical mechanism in the mixing zone in rotating and nonrotating systems.

Atomically Dispersed Zn-Stabilized Ni Enabling Tunable Selectivity for CO Hydrogenation.

For a heterogeneous catalytic process, the performance of catalysts could be improved by modifying the active metal with a second element. Determining the enhanced mechanism of the second element is essential to the rational design of catalysts. In this work, Zn was introduced as a second element into Ni/ZrO for CO hydrogenation.

Green Synthesis of Tunable Fluorescent Carbon Quantum Dots from Lignin and Their Application in Anti-Counterfeit Printing.

Lignin converted to carbon quantum dots (CQDs) attracts tremendous attention for large-scale production of carbon nanomaterials and value-added disposal of biomass wastes (such as the black liquor from pulping industry and the residue from hydrolysis of biomass). The green synthesis of lignin-derived CQDs is reported via a facile two-step method with the adjustment of acid additives containing N or S. The resulting series of CQDs exhibit bright fluorescence in gradient colors from blue to yellowish green, among which the N, S co-doped CQDs with the addition of 2,4-diaminobenzene sulfonic acid show an optimal fluorescence quantum yield (QY) of 30.

Understanding the Role of Endothelial Glycocalyx in Mechanotransduction via Computational Simulation: A Mini Review.

Endothelial glycocalyx (EG) is a forest-like structure, covering the lumen side of blood vessel walls. EG is exposed to the mechanical forces of blood flow, mainly shear, and closely associated with vascular regulation, health, diseases, and therapies. One hallmark function of the EG is mechanotransduction, which means the EG senses the mechanical signals from the blood flow and then transmits the signals into the cells.

A unified lattice Boltzmann model and application to multiphase flows.

In this work, we develop a unified lattice Boltzmann model (ULBM) framework that can seamlessly integrate the widely used lattice Boltzmann collision operators, including the Bhatnagar-Gross-Krook or single-relation-time, multiple-relaxation-time, central-moment or cascaded lattice Boltzmann method and multiple entropic operators (KBC). Such a framework clarifies the relations among the existing collision operators and greatly facilitates model comparison and development as well as coding. Importantly, any LB model or treatment constructed for a specific collision operator could be easily adopted by other operators.

Cross talk between endothelial and red blood cell glycocalyces via near-field flow.

Vascular endothelial cells and circulating red blood cell (RBC) surfaces are both covered by a layer of bushy glycocalyx. The interplay between these glycocalyx layers is hardly measurable and insufficiently understood. This study aims to investigate and qualify the possible interactions between the glycocalyces of RBCs and endothelial cells using mathematical modeling and numerical simulation.

Multiple-relaxation-time discrete Boltzmann modeling of multicomponent mixture with nonequilibrium effects.

A multiple-relaxation-time discrete Boltzmann model (DBM) is proposed for multicomponent mixtures, where compressible, hydrodynamic, and thermodynamic nonequilibrium effects are taken into account. It allows the specific heat ratio and the Prandtl number to be adjustable, and is suitable for both low and high speed fluid flows. From the physical side, besides being consistent with the multicomponent Navier-Stokes equations, Fick's law, and Stefan-Maxwell diffusion equation in the hydrodynamic limit, the DBM provides more kinetic information about the nonequilibrium effects.

Sodium ion transport across the endothelial glycocalyx layer under electric field conditions: A molecular dynamics study.

In the present research, the sodium ion transport across the endothelial glycocalyx layer (EGL) under an imposed electric field is investigated, for the first time, using a series of molecular dynamics simulations. The electric field is perpendicularly imposed on the EGL with varying strengths. The sodium ion molarity difference between the inner and outer layers of EGL, Δc, is used to quantify the sodium transport in the presence of the negatively charged glycocalyx sugar chains.

Effects of Acoustic Excitation on the Combustion Instability of Hydrogen-Methane Lean Premixed Swirling Flames.

Lean premixed flames are useful for low nitrogen oxide (NO ) emissions but more prone to induce combustion instability in gas turbines. Combustion instability of a lean premixed swirling flame (LPSF) with hydrogen-methane was investigated experimentally. The effects of hydrogen addition on combustion instability with equivalence ratios 0.