Hollow-SiO@Cu Zn Mg Al-LDHs as catalyst precursors for CO hydrogenation to methanol.

We report a new synthetic strategy for preparing well-organised, spherical and mesoporous, mixed-metal, hollow-core@layered double hydroxides. Hollow-SiO@Cu Zn Mg Al-LDHs ( + + = 2.32 ± 0.

Advanced systems for enhanced CO electroreduction.

Carbon dioxide (CO) electroreduction has extraordinary significance in curbing CO emissions while simultaneously producing value-added chemicals with economic and environmental benefits. In recent years, breakthroughs in designing catalysts, optimizing intrinsic activity, developing reactors, and elucidating reaction mechanisms have continuously driven the advancement of CO electroreduction. However, the industrialization of CO electroreduction remains a challenging task, with high energy consumption, high costs, limited reaction products, and restricted application scenarios being the issues that urgently need to be addressed.

Boosting NIR Laser Marking Efficiency of a Transparent Epoxy Using a Layered Double Hydroxide.

Efficient near-infrared (NIR) laser marking on transparent polymers like polypropylene, epoxy, and polyethylene has posed a big challenge due to their lack of absorption in the NIR. Currently, inorganic additives are used to improve NIR laser marking efficiency, but they come with issues such as toxicity, high loading requirement, adverse effects on color/opaqueness, and the need for low laser head speeds. Herein, we report a new strategy of incorporating a food-grade, MgAl-CO LDH as a boosting coadditive alongside the commercial NIR laser marking additive (Iriotech 8815) in an epoxy system.

Recent advances and perspectives on intercalation layered compounds part 1: design and applications in the field of energy.

Herein, initially, we present a general overview of the global financial support for chemistry devoted to materials science, specifically intercalation layered compounds (ILCs). Subsequently, the strategies to synthesise these host structures and the corresponding guest-host hybrid assemblies are exemplified on the basis of some families of materials, including pillared clays (PILCs), porous clay heterostructures (PCHs), zirconium phosphate (ZrP), layered double hydroxides (LDHs), graphite intercalation compounds (GICs), graphene-based materials, and MXenes. Additionally, a non-exhaustive survey on their possible application in the field of energy through electrochemical storage, mostly as electrode materials but also as electrolyte additives, is presented, including lithium technologies based on lithium ion batteries (LIBs), and beyond LiBs with a focus on possible alternatives such XIBs (X = Na (NIB), K (KIB), Al (AIB), Zn (ZIB), and Cl (CIB)), reversible Mg batteries (RMBs), dual-ion batteries (DIBs), Zn-air and Zn-sulphur batteries and supercapacitors as well as their relevance in other fields related to (opto)electronics.

Recent advances and perspectives for intercalation layered compounds. Part 2: applications in the field of catalysis, environment and health.

Intercalation compounds represent a unique class of materials that can be anisotropic (1D and 2D-based topology) or isotropic (3D) through their guest/host superlattice repetitive organisation. Intercalation refers to the reversible introduction of guest species with variable natures into a crystalline host lattice. Different host lattice structures have been used for the preparation of intercalation compounds, and many examples are produced by exploiting the flexibility and the ability of 2D-based hosts to accommodate different guest species, ranging from ions to complex molecules.

Mixing and matching ,- and ,-chelates in anionic Mg(I) compounds: synthesis and reactivity with RNCNR and CO.

Reduction of [Mg(NON)] ([NON] = [O(SiMeNDipp)], Dipp = 2,6-iPrCH) affords Mg(I) species containing NON- and NNO-ligands ([NNO] = [N(Dipp)SiMeN(Dipp)SiMeO]). The products of reactions with iPrNCNiPr and CO are consistent with the presence of reducing Mg(I) centres. Extraction with THF affords [K(THF)][(NNO)Mg-Mg(NNO)] with a structurally characterised Mg-Mg bond that was examined using density functional theory.

Europium insertion into MgAl hydrotalcite-like compound to promote the photocatalytic oxidation of nitrogen oxides.

Easy synthesis of efficient, non-toxic photocatalysts is a target to expand their potential applications. In this research, the role of Eu doping in the non-toxic, affordable, and easily prepared MgAl hydrotalcite-like compounds (HTlcs) was explored in order to prepare visible light semiconductors. Eu doped MgAl-HTlcs (MA-xEu) samples were prepared using a simple coprecipitation method (water, room temperature and atmospheric pressure) and europium was successfully incorporated into MgAl HTlc frameworks at various concentrations, with x (Eu/M percentage) ranging from 2 to 15.

Optimising the acid-base ratio of Mg-Al layered double oxides to enhance CO capture performance: the critical role of calcination conditions.

The effect of calcination conditions (ramp rate, calcination temperature and time) on the formation of MgAl layered double oxides (MgAl LDOs) as well as their CO capture performance, has been systematically investigated. This study explores novel insights into the intricate relationship between these calcination conditions and the resulting surface characteristics, which play a vital role in CO capture efficiency. Notably, it is revealed that a rapid ramp rate (100 °C min) significantly increases surface area and hydroxyl concentration, leading to a 69% increase in CO capture efficiency compared to slower ramp rate.

Trends in Structure and Ethylene Polymerization Reactivity of Transition-Metal Permethylindenyl-phenoxy (PHENI*) Complexes.

A family of -permethylindenyl-phenoxy (PHENI*) transition-metal chloride complexes has been synthesized and characterized (; {(η-CMe)Me(R″)Si(2-R-4-R'-CHO)}MCl; R,R' = Me, Bu, Cumyl (CMePh); R″ = Me, Pr, Ph; M = Ti, Zr, Hf). The ancillary chloride ligands could readily be exchanged with halides, alkyls, alkoxides, aryloxides, or amides to form PHENI* complexes [L]TiX (; X = Br, I, Me, CHSiMe, CHPh, NMe, OEt, ODipp). The solid-state crystal structures of these PHENI* complexes indicate that one of two conformations may be preferred, parametrized by a characteristic torsion angle (TA'), in which the η system is either disposed away from the metal center or toward it.

Interplay between Defects and Short-Range Disorder Manipulating the Oxygen Evolution Reaction on a Layered Double Hydroxide Electrocatalyst.

Improving the efficiency of the oxygen evolution reaction (OER) is crucial for advancing sustainable and environmentally friendly hydrogen energy. Layered double hydroxides (LDHs) have emerged as promising electrocatalysts for the OER. However, a thorough understanding of the impact of structural disorder and defects on the catalytic activity of LDHs remains limited.

Boosting the effectiveness of UV filters and sunscreen formulations using photostable, non-toxic inorganic platelets.

We have studied the size-dependent optical scattering of aqueous suspensions containing MgAl-LDH platelets, which exhibit high total- and side-scatterings. By incorporating 3 wt% MgAl-LDH platelets (280 nm) in a commercial sunscreen formulation, we achieved a twofold Sun Protection Factor boost, providing a promising, high-efficient and non-toxic strategy to enhance sunscreen effectiveness.

Towards designer polyolefins: highly tuneable olefin copolymerisation using a single permethylindenyl post-metallocene catalyst.

Using a highly active permethylindenyl-phenoxy (PHENI*) titanium catalyst, high to ultra-high molecular weight ethylene-linear-α-olefin (E/LAO) copolymers are prepared in high yields under mild conditions (2 bar, 30-90 °C). Controllable, efficient, and predictable comonomer enchainment provides access to a continuum of copolymer compositions and a vast range of material properties using a single monomer-agnostic catalyst. Multivariate statistical tools are employed that combine the tuneability of this system with the analytical and predictive power of data-derived models, this enables the targeting of polyolefins with designer properties directly through predictive alteration of reaction conditions.

Intrabasal Plane Defect Formation in NiFe Layered Double Hydroxides Enabling Efficient Electrochemical Water Oxidation.

Defect engineering has proven to be one of the most effective approaches for the design of high-performance electrocatalysts. Current methods to create defects typically follow a top-down strategy, cutting down the pristine materials into fragmented pieces with surface defects yet also heavily destroying the framework of materials that imposes restrictions on the further improvements in catalytic activity. Herein, we describe a bottom-up strategy to prepare free-standing NiFe layered double hydroxide (LDH) nanoplatelets with abundant internal defects by controlling their growth behavior in acidic conditions.

Fully tuneable ethylene-propylene elastomers using a supported permethylindenyl-phenoxy (PHENI*) catalyst.

Using a highly active supported permethylindenyl-phenoxy (PHENI*) titanium catalyst, high molecular weight ethylene-propylene (EPM) and ethylene-propylene-diene (EPDM) elastomers are prepared using slurry-phase catalysis. Final copolymer composition was found to reflect the monomer feed ratio in a linear fashion, to access a continuum of material properties with a single catalyst. Post-polymerisation crosslinking of EPDM was also demonstrated in a model sulfur vulcanisation system.

Core-shell silica@CuZnAl LDH catalysts for efficient CO hydrogenation to methanol.

The efficient production of methanol by reduction of CO using green hydrogen is a promising strategy from both a green chemistry and a carbon net zero perspective. Herein, we report the synthesis of well-dispersed core-shell catalyst precursors using silica@CuZnAl-LDHs that can convert CO to methanol. The catalyst precursors can be formed using either a commercially available silica (ES757) or a mesoporous silica ( MCM-48).

Hydrogen-bonding and resonance stabilisation effects in cationic bis(iminium) phenoxide diacids.

The synthesis and characterisation of a bis(iminium)phenoxide diacid cation [4-Bu-CH-2,6-(HCN(H)Dipp)-1-O] ([HL]), is discussed. [HL][BF] (1) and [HL][HN{B(CF)}] (2) were synthesised in high yields protonation of the bis(imino)phenol conjugate base with ethereal HBF or Bochmann's acid ([H(OEt)][HN{B(CF)}]). Both species were fully characterised using NMR and IR spectroscopy as well as X-ray crystallography.

Multimetallic Permethylpentalene Hydride Complexes.

The synthesis and characterization of group 4 permethylpentalene (Pn* = CMe) hydride complexes are explored; in all cases, multimetallic hydride clusters were obtained. Group 4 lithium metal hydride clusters were obtained when reacting the metal dihalides with hydride transfer reagents such as LiAlH, and these species featured an unusual hexagonal bipyramidal structural motif. Only the zirconium analogue was found to undergo hydride exchange in the presence of deuterium.

Recent advances in direct air capture by adsorption.

Significant progress has been made in direct air capture (DAC) in recent years. Evidence suggests that the large-scale deployment of DAC by adsorption would be technically feasible for gigatons of CO capture annually. However, great efforts in adsorption-based DAC technologies are still required.

NiMn-layered double oxide electrodes in organic electrolyte based supercapacitors.

The development of future mobility ( electric vehicles) requires supercapacitors with high voltage and high energy density. Conventional active carbon-based supercapacitors have almost reached their limit of energy density which is still far below the desired performance. Advanced materials, particularly metal hydroxides/oxides with tailored structure are promising supercapacitor electrodes to push the limit of energy density.

Synthesis of zirconocene complexes and their use in slurry-phase polymerisation of ethylene.

A new family of zirconocene complexes of the type (Ind)ZrX (where Ind = CMeH and R = Me, Et and Ph) have been synthesised and fully characterised. Six new crystal structures have been reported (-(Ind)ZrBr, -(Ind)ZrCl, -(Ind)Zr(CHPh), -(Ind)Zr(CHPh), -(Ind)ZrBr and -(Ind)Zr(CHPh)). The complexes were studied for slurry-phase ethylene polymerisation when immobilised on solid polymethylaluminoxane (sMAO).

Aged layered double hydroxide nanosheet-polyvinyl alcohol dispersions for enhanced gas barrier coating performance.

Whilst applying a coating layer to a polymer film is a routine approach to enhance the gas barrier properties of the film, it is counter-intuitive to consider that the gas barrier performance of the film would improve by ageing the coating dispersion for weeks before application. Herein, we report that the oxygen barrier performance of a 12 μm PET film coated with a dispersion of inorganic nanosheets in polyvinyl alcohol can be significantly enhanced by ageing this coating dispersion for up to 8 weeks before application. We found up to a 37-fold decrease in the oxygen transmission rate (OTR) of the PET coated film using aged dispersions of [MgAl(OH)](NO) layered double hydroxide nanosheets (MgAl-LDH NS) in polyvinyl alcohol (PVA) compared to the film coated with an equivalent freshly prepared LDH/PVA dispersion.

Supported permethylindenyl titanium catalysts for the synthesis of disentangled ultra-high molecular weight polyethylene (disUHMWPE).

Novel permethylindenyl-phenoxide (PHENI*) ansa-metallocene titanium complexes have been synthesised and immobilised on inorganic solid supports to afford highly effective catalysts for slurry-phase ethylene polymerisation. When supported on solid polymethylaluminoxane these complexes were both extremely active (up to 3.7 × 10 g mol h bar) and produced substantially disentangled polyethylene with a weight-average molecular weight (M) of 3.

High-efficiency CO separation using hybrid LDH-polymer membranes.

Membrane-based gas separation exhibits many advantages over other conventional techniques; however, the construction of membranes with simultaneous high selectivity and permeability remains a major challenge. Herein, (LDH/FAS)-PDMS hybrid membranes, containing two-dimensional sub-nanometre channels were fabricated via self-assembly of unilamellar layered double hydroxide (LDH) nanosheets and formamidine sulfinic acid (FAS), followed by spray-coating with a poly(dimethylsiloxane) (PDMS) layer. A CO transmission rate for (LDH/FAS)-PDMS of 7748 GPU together with CO selectivity factors (SF) for SF(CO/H), SF(CO/N) and SF(CO/CH) mixtures as high as 43, 86 and 62 respectively are observed.

Ring-opening polymerisation of l- and rac-lactide using group 4 permethylpentalene aryloxides and alkoxides.

A new family of group 4 permethylpentalene (CMe; Pn*) aryloxide and alkoxide complexes have been synthesised and fully characterised by multinuclear NMR spectroscopy and single-crystal X-ray diffraction; (η-CMe)Zr(OR) (R = Bu (1), 2,6-Me-CH (2), 2,6-Pr-CH (3) and 4-OMe-CH (4)), (η-CMe)Zr (OR) (R = 2,6-Bu-CH (5) and 2,6-Bu-4-Me-CH (6)), (η-CMe)ZrCp(OR) (R = Bu (7), 2,6-Me-CH (8) and 2,6-Pr-CH (9)), (η-CMe)TiCp(O-2,6-Me-CH) (10) and (η-CMe)ZrCp(OR) (R = 2,6-Me-CH (11), 2,6-Pr-CH (12) and 2,4-Bu-CH (13)). 2, 3, 6, 7, 9, 10 and 12 were studied as initiators for the ring-opening polymerisation (ROP) of l-lactide, and 2, 3, 6, 7 and 10 were studied as initiators for the ROP of rac-lactide. 3 was found to be the most active initiator for the ROP of l-lactide (k = 0.