Dynamic Covalent Sulfur-Selenium Rich Polymers via Inverse Vulcanization for High Refractive Index, High Transmittance, and UV Shielding Materials.

Recent advancements in inverse vulcanization have led to the development of sulfur-rich polymers with diverse applications. However, progress is constrained by the harsh high-temperature reaction conditions, limited applicability, and the generation of hazardous HS gas. This study presents an induced IV method utilizing selenium octanoic acid, yielding sulfur-selenium rich polymers with full atom economy, even at a low-temperatures of 100-120 °C.

Realizing an Energy-Dense Potassium Metal Battery at -40 °C via an Integrated Anode-Free and Dual-Ion Strategy.

Potassium (K)-based batteries hold great promise for cryogenic applications owing to the small Stokes radius and weak Lewis acidity of K. Nevertheless, energy-dense (>200 W h kg) K batteries under subzero conditions have seldom been reported. Here, an over 400 W h kg K battery is realized at -40 °C via an anode-free and dual-ion strategy, surpassing these state-of-the-art K batteries and even most Li/Na batteries at low temperatures (LTs).

Catalytic Deconstruction of Commercial and End-Of-Life Polyurethane with Heterogeneous Hydrogenation Catalyst.

Polyurethane (PU), as a thermoset polymer, is extensively utilized in various applications, such as refrigerator foams, sponges, elastomers, shoes, etc. However, the recycling of post-consumed PU poses significant challenges due to its intricate and extensive crosslinking structures. Catalytic hydrogenation is one of the most effective methods for recycling PU waste, nevertheless, there is currently a lack for a hydrogenation catalyst that is both high-performing, recyclable, and cost-effective for breaking down post-consumed PU materials.

Rational design of water splitting electrocatalysts through computational insights.

Electrocatalytic water splitting is vital for the sustainable production of green hydrogen. Electrocatalysts, including those for the hydrogen evolution reaction at the cathode and the oxygen evolution reaction at the anode, are crucial in determining the overall performance of water splitting. Traditional methods for electrocatalyst development often rely on trial-and-error, which can be time-consuming and inefficient.

The Effects of Internal Electron Donors on MgCl-Supported Ziegler-Natta Catalysts for Isotactic PP.

The electron donors (ED) in Ziegler-Natta (Z-N) catalysis are classified as internal electron donors (IED) and external electron donors (EED), and both IED and EED are indispensable components for enhancing the catalytic reactivity and regulating the stereoregularity of polyolefinic materials in a typical industrial Z-N catalytic process. With the intensive research on ED, the Z-N catalyst performances have experienced successive progress in the last few decades. Polypropylenes (PP) as a commodity polyolefin material, especially the isotactic PP (iPP), are produced in multi-billion pounds per annum by utilization of the various IED- and EED-assisted Z-N catalysts systems.

Boosting Acidic Hydrogen Evolution Kinetics Induced by Weak Strain Effect in PdPt Alloy for Proton Exchange Membrane Water Electrolyzers.

Strain engineering is an effective strategy for manipulating the electronic structure of active sites and altering the binding strength toward adsorbates during the hydrogen evolution reaction (HER). However, the effects of weak and strong strain engineering on the HER catalytic activity have not been fully explored. Herein, the core-shell PdPt alloys with two-layer Pt shells (PdPt) and multi-layer Pt shells (PdPt) is constructed, which exhibit distinct lattice strains.

()-Selective Isomerization of 1,1-Disubstituted Alkenes by Scandium-Catalyzed Allylic C-H Activation.

The isomerization of 1,1-disubstituted alkenes through 1,3-hydrogen shift is an atom-efficient route for synthesizing trisubstituted alkenes, which are important moieties in many natural products, pharmaceuticals, and organic materials. However, this reaction often encounters regio- and stereoselectivity challenges, typically yielding /-mixtures of the alkene products or thermodynamically favored ()-alkenes. Herein, we report the ()-selective isomerization of 1,1-disubstituted alkenes to trisubstituted ()-alkenes via the regio- and stereospecific activation of an allylic C-H bond.

Nitrogen-rich and core-sheath polyamide/polyethyleneimine@Zr-MOF for iodine adsorption and nerve agent simulant degradation.

Radioactive nuclides and highly toxic organophosphates are typical deadly threats. Materials with the function of radioactive substances adsorption and organophosphates degradation provide double protection. Herein, dual-functional polyamide (PA)/polyethyleneimine (PEI)@Zr-MOF fiber composite membranes, fabricated by in-situ solvothermal growth of Zr-MOF on PA/PEI electrospun fiber membranes, are designed for protection against two typical model compounds of iodine and dimethyl 4-nitrophenyl phosphate (DMNP).

Conventional Hydrothermal Synthesis of MFI Zeolite in Methanol Solution.

The synthesis of zeolites through more efficient, environmentally friendly, and cost-effective methods was deemed significant in both industrial applications and academic fields. Conventional hydrothermal synthesis strategies have encountered difficulties in producing pure silica MFI zeolite (silicalite-1) under amine-free conditions. This was primarily attributed to the competitive growth of quartz, keatite, or magadiite during the crystallization process.

Constructing CoP/NiP Heterostructure Confined Ru Sub-Nanoclusters for Enhanced Water Splitting in Wide pH Conditions.

Developing efficient electrocatalysts for water splitting is of great significance for realizing sustainable energy conversion. In this work, Ru sub-nanoclusters anchored on cobalt-nickel bimetallic phosphides (Ru-CoP/NiP) are constructed by an interfacial confinement strategy. Remarkably, Ru-CoP/NiP with low noble metal loading (33.

UiO-66/PIM-1 Mixed-Matrix Membrane for Hexane Isomer Separation.

The separation of high-octane dibranched alkanes from naphtha is critical in the refining of gasoline. To date, research on the membrane-based separation of alkane isomers has been limited, with a particular paucity of investigations into mixed-matrix membranes. Herein, the continuous and dense UiO-66/PIM-1 mixed-matrix membrane, which was prepared through precise control of the interfacial structure, was first applied to the differentiation of C alkane isomers.

Catalytic Activity of 2-Imino-1,10-phenthrolyl Fe/Co Complexes via Linear Machine Learning.

In anticipation of the correlations between catalyst structures and their properties, the catalytic activities of 2-imino-1,10-phenanthrolyl iron and cobalt metal complexes are quantitatively investigated via linear machine learning (ML) algorithms. Comparatively, the Ridge Regression model has captured more robust predictive performance compared with other linear algorithms, with a correlation coefficient value of 0.952 and a cross-validation value of 0.

Theoretical investigations of 2-vinylpyridine stereoselective polymerization catalyzed by cationic yttrium complexes with different ancillary ligands.

The polymerization mechanism of 2-vinylpyridine catalyzed by cationic yttrium complexes with diverse ancillary ligands, specifically [L1Y(CHSiMe)(THF)] [L1 = (2,6-EtCH)NC(Me)CHC(Me)N(2,6-EtCH)] (Y-1), [L2Y(CHSiMe)(THF)] [L2 = (2,6-ClCH)NC(Me)CHC(Me)N(2,6-ClCH)] (Y-2), and [L3Y(CHSiMe)(THF)] [L3 = (2,6-CH)NC(Me)CHC(Me)N(2,6-PrCH)] (Y-3), was studied using density functional theory (DFT) calculations. Having achieved an agreement between theory and experiment, it is found that isotactic selectivity induced by Y-1 or Y-2 results from a combination of smaller deformation of the catalyst and stronger electronic effects. Conversely, the Y-3 complex exhibits comparable energy barriers for proceeding either isotactic or syndiotactic pathways, aligning with the production of atactic polymers as seen experimentally.

Data-Driven Discovery of Gas-Selective Organic Linkers in Metal-Organic Frameworks for the Separation of Ethylene and Ethane.

Metal-organic frameworks (MOFs) are potential candidates for gas-selective adsorbents for the separation of an ethylene/ethane mixture. To accelerate material discovery, high-throughput computational screening is a viable solution. However, classical force fields, which were widely employed in recent studies of MOF adsorbents, have been criticized for their failure to cover complicated interactions such as those involving π electrons.

Dinitrogen Cleavage and Multicoupling with Isocyanides in a Dititanium Dihydride Framework.

Dinitrogen (N) activation and functionalization through N-N bond cleavage and N-C bond formation are of great interest and importance but remain highly challenging. We report here for the first time N cleavage and selective multicoupling with isocyanides in a dititanium dihydride framework. The reaction of a dinitrogen dititanium dihydride complex [{(PNP)Ti}(μ-η:η-N)(μ-H)] () with an excess (four or more equivalents) of -methoxyphenyl isocyanide at room temperature gave a novel amidoamidinatoguanidinate complex [(PNP)Ti{NC(═NR)NC(═NR)CHNR}Ti(PNP)(CNR)] (, PNP = 4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9-acridin-10-ide; R = -MeOCH) through N splitting and coupling with three isocyanide molecules.

Polar Molecules Regulating the Regio- and Stereoselectivity of Polymerization of Conjugated Dienes Catalyzed by CGC-Type Rare-Earth Metal Catalysts.

Herein, a concise, effective, and scalable strategy is reported that the introduction of polar molecules (PMs) (e.g., anisole (PhOMe), phenetole (PhOEt), 2-methoxynaphthalene (NaphOMe), thioanisole (PhSMe), and N,N-dimethylaniline (PhNMe)) as continuously coordinated neutral ligand of cationic active species in situ generated from the constrain-geometry-configuration-type rare-earth metal complexes A-F/AlBu/[PhC][B(CF)] ternary systems can easily switch the regio- and stereoselectivity of the polymerization of conjugated dienes (CDs, including 2-subsituted CDs such as isoprene (IP) and myrcene (MY), 1,2-disubstituted CD ocimene (OC), and 1-substituted polar CD 1-(para-methoxyphenyl)-1,3-butadiene (p-MOPB)) from poor selectivities to high selectivities (for IP and MY: 3,4-selectivity up to 99%; for OC: trans-1,2-selectivity up to 93% (mm up to 90%); for p-MOPB: 3,4-syndioselectivity (3,4- up to 99%, rrrr up to 96%)).

Predicting the catalytic activities of transition metal (Cr, Fe, Co, Ni) complexes towards ethylene polymerization by machine learning.

The study aims to execute machine learning (ML) method for building an intelligent prediction system for catalytic activities of a relatively big dataset of 1056 transition metal complex precatalysts in ethylene polymerization. Among 14 different algorithms, the CatBoost ensemble model provides the best prediction with the correlation coefficient (R ) values of 0.999 for training set and 0.

Unravelling the Impact of Metal Dopants and Oxygen Vacancies on Syngas Conversion over Oxides: A Machine Learning-Accelerated Study of CO Activation on Cr-Doped ZnO Surfaces.

As a critical component of the OX-ZEO composite catalysts toward syngas conversion, the Cr-doped ZnO ternary system can be considered as a model system for understanding oxide catalysts. However, due to the complexity of its structures, traditional approaches, both experimental and theoretical, encounter significant challenges. Herein, we employ machine learning-accelerated methods, including grand canonical Monte Carlo and genetic algorithm, to explore the ZnO(1010) surface with various Cr and oxygen vacancy (OV) concentrations.

Mechanistic Studies on Aluminum-Catalyzed Ring-Opening Alternating Copolymerization of Maleic Anhydride with Epoxides: Ligand Effects and Quantitative Structure-Activity Relationship Model.

Previous work has indicated that aluminum (Al) complexes supported by a bipyridine bisphenolate (BpyBph) ligand exhibit higher activity in the ring-opening copolymerization (ROCOP) of maleic anhydride (MAH) and propylene oxide (PO) than their salen counterparts. Such a ligand effect in Al-catalyzed MAH-PO copolymerization reactions has yet to be clarified. Herein, the origin and applicability of the ligand effect have been explored by density functional theory, based on the mechanistic analysis for chain initiation and propagation.

High-Efficiency Mono-Cyclopentadienyl Titanium and Rare-Earth Metal Catalysts for the Production of Syndiotactic Polystyrene.

Syndiotactic polystyrene (SPS) refers to a type of thermoplastic material with phenyl substituents that are alternately chirally attached on both sides of an aliphatic macromolecular main chain. Owing to its excellent physical and mechanical properties, as well as its chemical stability, high transparency, and electrical insulation characteristics, SPS is used in a wide variety of technical fields. SPS is commonly produced via the stereoselective transition metal-catalyzed coordination polymerization method mediated by stereospecific catalysts, which consists of anionic mono-cyclopentadienyl derivative η-coordinated single active metal centers (referred to as "mono-Cp'-M"), with active center metals involving Group 4 transition metals (with an emphasis on titanium) and rare-earth (RE) metals of the periodic table.

Graph Transformer with Convolution Parallel Networks for Predicting Single and Binary Component Adsorption Performance of Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) are considered one of the most important materials for carbon capture and storage (CCS) due to the advantages of porosity, multifunction, diverse structure, and controllable chemical composition. With the continuous development of artificial intelligence (AI) technology, more and more machine learning models are used to identify MOFs with high performance within a massive search space. However, current works have yet to form a model that uses graph-structured data only, which can predict the adsorption properties of single and binary components.

Using a single complex to predict the reaction energy profile: a case study of Pd/Ni-catalyzed ethylene polymerization.

Mechanism-driven catalyst screening could be greatly accelerated by quantitative prediction models of the reaction energy profile. Here, we propose a novel method for molecular representation, taking palladium- and nickel-catalyzed ethylene polymerization as model reactions. The geometric parameters (GPfra) and electron occupancies (EOfra) from the non-ligand fragment of the η-complex were extracted as the molecular descriptors, followed by constructing the reaction energy profile prediction models on the basis of various regression algorithms.

Aza-Michael Addition of Dinitrogen to α,β-Unsaturated Carbonyl Compounds in a Dititanium Framework.

The direct use of dinitrogen (N) as a building block for the synthesis of NN-containing organic compounds is of fundamental interest and practical importance but has remained a formidable challenge to date. Here, we report an unprecedented 1,4-conjugate (aza-Michael) addition of N to α,β-unsaturated carbonyl compounds in a dititanium framework. The resulting hydrazinopropenolate products could be easily converted to diverse NN-containing organic compounds such as β-hydrazine-functionalized esters and amides, pyrazolidinones, and pyrazolines depending on the types of Michael acceptors through protonation with MeOH.

Hydrogen bond recombination regulated by strongly electronegative functional groups in demulsifiers for efficient separation of oil-water emulsions.

Tight oil extraction and offshore oil spills generate large amounts of oil-water emulsions, causing serious soil and marine pollution. In such oil-water emulsions, the resin molecules are bound by π-π stacking and bind to interfacial water molecules via hydrogen bonds, which impede the aggregation between water droplets and thereby the separation of the emulsion. In this study, strongly electronegative oxygen atoms (in ethylene oxide, propylene oxide, esters, and hydroxyl groups) were introduced through poly(propylene glycol)-block-polyether and esterification with acrylic acid to attract negative charges in order to form electron-rich regions and enhance interfacial hydrogen bond recombination.

Comprehensive Study of Oxygen Vacancies on the Catalytic Performance of ZnO for CO/H Activation Using Machine Learning-Accelerated First-Principles Simulations.

Oxygen vacancies (OVs) play important roles on any oxide catalysts. In this work, using an investigation of the OV effects on ZnO(101̅0) for CO and H activation as an example, we demonstrate, via machine learning potentials (MLPs), genetic algorithm (GA)-based global optimization, and density functional theory (DFT) validations, that the ZnO(101̅0) surface with 0.33 ML OVs is the most likely surface configuration under experimental conditions (673 K and 2.