Liquid organic hydrogen carriers (LOHCs) are an attractive fuel source due to their compatibility with existing transportation methods and ease of use. However, they suffer from sluggish (de)hydrogenation kinetics. One promising platform for developing next-generation catalysts is metal-organic frameworks (MOFs), which can enable systematic interrogation into the influence of metal identity and spatial arrangement. In this study, the effect of the coordination environment was investigated using Ni- and Co-based azolate MOFs: MFU-4l-OH (MxZn5-x(OH)4(BTDD)3; x = 4 for M = Co and x = 3 for M = Ni, H2BTDD = bis(1H-1,2,3-triazolo[4,5-b][4',5'-i])dibenzo[1,4]dioxin), composed of single-site nodes, and M(OH)2BBTA (M = Ni, Co; H2BBTA = 1H,5H-benzo(1,2-d:4,5-d')bistriazole), composed of extended chain-type nodes. The catalysts were characterized by isotherms, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and X-ray photoelectron spectroscopy (XPS) analysis. Acetylene hydrogenation activity under steady state conditions (150 °C, 1:1 C2H2:H2) revealed higher turnover frequencies (TOFs) up 1.8 × 10-4 min-1 and 3.0 × 10-5 min-1 for Ni-MFU-4l-OH and Co-MFU-4l-OH, respectively, compared to their BBTA analogues. However, the Co-based MOFs, particularly Co2(OH)2-BBTA, exhibited greater selectivity (up to 19%) for the fully hydrogenated ethane product. Isosteric heat of adsorption (Qst) measurements for ethylene and ethane revealed that the BBTA framework had stronger binding to the products than MFU-4l. These findings demonstrate that metal identity and coordination environment may modulate acetylene hydrogenation performance, leading to design principles for tuning LOHC hydrogenation catalysts.

Conversion of CO2 into useful products offers promising pathways towards achieving global carbon neutrality, and the development of corresponding advanced catalysts is important but challenging. Many catalysts can facilitate the conversion of CO2 into mono-carbon C1 products (such as carbon monoxide and formic acid), while conversion of CO2 into high-value-added multi-carbon compounds (such as ethylene and ethanol) requires multiple proton-coupled-electron-transfer (PCET) steps and targeted control product selectivity, which remain difficult to achieve in most catalysts. Single atom catalysts (SACs) demonstrate great potential for efficiently electrolyzing CO2 molecules into high valued chemicals with striking features, including atomically dispersed metal centres, well defined coordination environments, and tuneable electronic structures. In this review, the latest advances in SACs for CO2 conversion are comprehensively summarized, highlighting how SACs design influences product selectivity in CO2 reduction reactions, particularly for challenging C2 products with higher volumetric energy densities and market value. The fundamentals of SACs are first introduced, highlighting their unique advantages and outlining state-of-the-art design strategies and modification methods for performance optimization. The catalytic mechanism of CO2 on SACs is then delved into and their inspiration for SACs design is elucidated. Most importantly, the latest representative examples of engineered SACs for the electrochemical CO2 reduction reaction and design principles are presented and how novel SACs engineering enhances their activity, selectivity and stability is discussed, providing guidance for the development of efficient and durable SACs. Finally, the current challenges and limitations in this field are identified and future research opportunities are proposed, suggesting concepts for creating durable and highly active catalytic platforms for CO2 conversion and further applications.

Anode-free sodium metal batteries (AFSMBs) promise high energy density and cost-effectiveness, yet their all-climate practical implementation remains limited by sluggish low-temperature kinetics. Here, we report a molecular wedging strategy for electrolyte design to reconstruct the solvation structure, extending the wide-temperature function of high-energy-density AFSMBs and Ah-level pouch cells. The wedging effect is synergistically achieved by intermolecular interactions and steric hindrances, so that the noncoordinating and spatially bulky cosolvent "wedges" into the rigid solvation structure dominated by strongly solvating solvent, rendering both electrostatically and spatially disrupted coordination environments and local structural disordering for fast mass transport and facile charge transfer. Highly reversible Na plating/stripping with Coulombic efficiency up to 99.98% and long-term cycling stability with overpotential <30 mV are ensured across a wide temperature range from 25 °C to -40 °C. With reconciled wide-temperature kinetics and anion-dominant interfacial chemistry, the molecular-wedging electrolyte enables high-cathode-loading AFSMBs with a discharging capacity as high as 93 mAh g-1 (85% of its room-temperature theoretical capacity) and reversible cycling exceeding 205 cycles down to -40 °C. Remarkably, Ah-level C@All||Na3V2(PO4)3 anode-free pouch cells (up to 3 Ah) demonstrate stable wide-temperature operation, yielding a high energy density of 170 Wh kg-1 and a cumulative cycling capacity of 690 Ah at an ultralow temperature of -40 °C, while a 2.5 Ah C@All||NaNi1/3Fe1/3Mn1/3O2 anode-free pouch cell achieves a further elevated energy density of 184 Wh kg-1 based on total cell weight within a cutoff voltage of 2.0-4.2 V.

Coordination polymers (CPs) often suffer from poor hydrolytic and chemical stability, limiting their use in water remediation. Herein, we report a highly robust, amorphous CP synthesized from Zr4+ and phytic acid, a natural source of phosphorus in plants and seeds. The CP, which features stable Zr-O-P bonds that resist degradation even in 10 M HCl and HNO3, forms a micro- and mesoporous network under mild reaction conditions in water. The material consists of mononuclear ZrO6 units bridged by phosphate groups. Zr-Phytate exhibits excellent Pb2+ removal performance, maintaining high efficiency even in the presence of excess competing ions. Pair Distribution Function (PDF) analysis and solid-state NMR (ssNMR) provide insight into the coordination environment of the Zr-phosphate centers and the mechanism of lead complexation. The exceptional chemical durability of Zr-Phytate allows efficient regeneration using 1 M HCl, with no detectable leaching of Zr or phytic acid and no loss of structural integrity over multiple cycles. Compared to commercial ion-exchange resins, Zr-Phytate offers superior selectivity and reusability. This work demonstrates the importance of designing stable coordination polymers and highlights the promise of zirconium-phosphate networks for applications in water remediation.

The ligand LH8Cl2 (LH6·2HCl) [(3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)]pyridine-2,6-dicarbohydrazide dichloride] was prepared from the Schiff base condensation of pyridine-2,6-dicarbohydrazide with pyridoxal hydrochloride in methanol. Reaction of LH6·2HCl with CuCl2·4H2O or Cu(ClO4)2·6H2O in a MeOH/water mixture produced two 1-D copper coordination polymers with formulae {[Cu3(LH4)Cl3(H2O)]Cl·H2O}n (1) and {[Cu3(LH4)Cl(H2O)2(ClO4)][ClO4]2·2H2O}n (2) respectively. Similarly, reaction of LH6·2HCl with NiCl2·6H2O, Ni(ClO4)2·4H2O or Ni(NO3)2·6H2O afforded the trimetallic complex [Ni3(LH4)(H2O)9]Cl4·4H2O (3), the 1-D polymer {[Ni3(LH4)(NO3)(H2O)6](NO3)2·H2O}n (4) and [Ni2(LH6)(H2O)6](ClO4)4·3H2O (5). The crystal structures of 1-5 were determined by X-ray diffraction. All complexes 1-4 exhibit the same geometric arrangement of the ligand with the central metal linked to the terminal metal ions by a trans-diazine linker with the diazine and pyridoxal arms coordinating in a tridentate NO2 donor fashion, while the central metal atom is coordinated by the ligand in a tridentate fashion by the pyridine and two diazine-N atoms. Water and coordinating anions complete the coordination environment around the Cu2+ and Ni2+ ions. The ligand adopts the same geometry in 5 but is not deprotonated and does not possess a central metal atom. Magnetic measurements (5-300 K) reflect strong antiferromagnetic exchange across the 1,2-diazine bridge.

In this study, coordination-induced spin state switching (CISSS) functionality was achieved through a dynamic coordination polymerization process. A discrete grid [Ni4(hnih)4(py)8]·6MeOH (1·py) based on a nitro-decorated isonicotinoylhydrazide ligand underwent ring-opening coordination polymerization into three one-dimensional chains [Ni(hnih)(py)2·py]n (2·py), [Ni(hnih)(DMSO)2·DMSO]n (2·DMSO), and [Ni(hnih)]n (2), of which the transformation involved coordination sphere rearrangement and topologic change. Optical and magnetic studies demonstrated that the reversible high spin (HS) ↔ low spin (LS) transitions can be achieved in the solid state between the octahedral species (1·py, 2·py, and 2·DMSO) and the square planar complex 2 via a CISSS process. This work introduces a crystal-transformation-driven strategy to achieve and regulate CISSS functionality in dynamic coordination polymers, paving the way for solid-state stimuli-responsive materials.

Tuning electronic structure via coordination sphere in Fe(III) anchored covalent triazine framework for boosting light-driven peroxymonosulfate activation

Cu/Cu2O nanoparticles supported on electrospun carbon nanofibers as high-performance cathodic catalyst for photocatalytic fuel cell.

Establishing the fundamental possibility of the existence of the heteroligand macrotetracyclic complexes of vanadium, chromium, manganese, and iron-containing in the inner coordination sphere phthalocyanine, oxygen (O2-) and fluorine (F-) ions and having general [MPc(O)F] formula (M= V, Cr, Mn, Fe), by using of quantum-chemical calculation of parameters of their molecular/electronic structures and thermodynamical characteristics. The molecular and electronic structures of the above-mentioned heteroligand macrotetracyclic chelates of 3d-elements (M) of the type [MPc(O)F] (M= V, Cr, Mn, Fe) which are unknown at present, were theoretically investigated. Standard thermodynamic parameters of formation (standard enthalpy ΔH0 f, 298, entropy S0 f, 298, and Gibbs’s energy ΔG0 f, 298) for these macrocyclic compounds were calculated, too. Identifying details of molecular and electronic structures of compounds indicated above. Density functional theory (DFT) model chemistries (B3PW91/TZVP and OPBE/TZVP) with a combination of the D3 version of Grimme’s dispersion. The data on the geometric parameters of the molecular structure of these complexes are presented; it was shown that MN4 chelate nodes, all metal-chelate and 6-membered non-chelate rings in each of these macrocyclic coordination compounds, are practically planar with a small deviation from coplanarity (not more 3o); nonetheless, N4 grouping from donor nitrogen atoms and 5-membered non-chelate rings are strictly planar. Wherein, the bond angles between two donor nitrogen atoms and M atom are not equal to 90o; a similar situation occurs for the bond angles between donor atoms N, M, and O or F (notwithstanding the bond angles formed by M, O, and F atoms are exactly 180°). Also, NBO analysis data and the values of the standard enthalpy, entropy, and Gibbs energy of the formation of these compounds were presented. Specific features of DFT calculated molecular and electronic structures of the heteroligand metal macrocyclic compounds have been discussed. It has been shown that good agreement between the parameters of molecular structures obtained by two various DFT model chemistries takes place. Also, it has been noted that predicting the possibility of the existence of exotic coordination compounds and modeling their molecular/electronic structures using modern quantum chemical calculations (and, in particular, using DFT of various levels) is a very useful tool for solving problems associated with such synthesis.

Tantalum doping triggered electronic reconfiguration of cobalt phosphide for efficient and stable overall seawater splitting.

Metal defects and ruthenium single-atom cooperative catalysis for efficient acidic oxygen evolution reaction.

In situ co-formation of NiO nanoclusters and nickel‑nitrogen-doped carbon enables hierarchical electronic modulation of Pt for efficient methanol oxidation at low Pt loading.

Synergistic Cr doping engineering modulates interfacial built-in electric field and lattice oxygen activation for enhanced electrocatalytic water splitting.

Construction of Mn2O3/SmMn2O5 interface with tuned Mn coordination environment for efficient air pollutant elimination

Abstract Advanced PVDF‐based electrolytes with ceramic‐like ion migration behavior, near‐separator‐level toughness, and excellent oxidation resistance are critical for the practical implementation of solid‐state lithium‐metal batteries (SSLMBs). However, the superior ion conductivity, robust mechanical property, and wide electrochemical stability usually cannot be achieved simultaneously. Herein, the self‐defective silicon (Si) fillers with silicon/silicon oxide (Si/SiO x ,0&lt;x≤2) heterogeneous interfaces are doped into the PVDF matrix to construct the highly conductive and supertough PVDF‐based electrolytes. Results reveal that the self‐defective Si will spontaneously participate in the Li + ‐solvation state and convert all solvation structure into the Li + ‐[solvent] x ‐[anion] y (x≤y) configuration. The anion‐rich Li + coordination environment not only accelerate Li + diffusion rate but also promotes the formation of the anion‐dominated bilayer interphase. Meanwhile, the strong Lewis acid‐base interaction of PVDF/SiO x interface effectively suppresses phase separation initiated by uneven solvent evaporation. Benefiting from the modified Li + transport environment and phase regulation, the obtained electrolytes exhibit impressive comprehensive properties, including ionic conductivity of 0.44 mS cm −1 , tensile strength of 16.5 Mpa, and voltage window of 5.07 V. Besides, the Li||Li symmetrical batteries present outstanding cycling under the current density of 0.1 mA cm −2 (&gt;6200 h), and the LFP||Li batteries exhibit remarkable fast‐charging behavior at 10 C with the capacity retention of 82.29%.

As the smallest one-dimensional structure, single-atom chains exhibit many one-dimensional quantized behaviors, such as Tomonaga-Luttinger liquid behavior, high-temperature superconductivity, and fluctuations. In contrast to single-atom catalysts, there is growing interest in exploring whether and how the point-to-point interaction occurs between neighboring metal atoms in 1D chains. Here, we controllably fabricate Pt chains and single atoms in MoS2 films with similar coordination environments and conduct model studies on their catalytic behaviors in hydrogen production. Combining calculations with field effect transistor and micro-electrochemical measurements, we reveal that the chains exhibit significant delocalized electron densities, which underpins their metallic behavior and engenders a fascinating center site with lower Gibbs free energy than that of single atoms. Notably, we demonstrate that the chain density can be well-tuned, achieving a maximum of 2.82 Pt/nm2, which enables a competitive turnover frequency and wafer-scale hydrogen production. This work offers insights into our understanding of the possible synergistic effect between metal atoms in a 1D arrangement for electrocatalysis.

The synthesis of VOx/MgO catalysts by solution combustion synthesis was investigated using varying molar ratios of glycine to oxidant. The effect of varying the fuel amount on morphology, phase composition, surface area, crystallite size, elemental distribution, and coordination environment around V was investigated. The results showed that the morphology, surface area, and crystallite size are all dependent on the flame temperature during the combustion process, which is dependent on the amount of fuel added. Results also suggested that adding glycine in excess lowers the combustion temperature. The catalysts were tested for the ODH of n-octane. The catalyst with superior catalytic properties was the stoichiometric sample, in which equal molar ratios of the fuel and oxidizer were added. The better catalytic performance was related to the contribution of the VOx species from the magnesium vanadate phase. This is the only sample in which vanadates were detected. Catalysts synthesized under fuel-lean and fuel-rich conditions were characterized by large crystallites and the absence of detectable magnesium vanadates, using XRD.

Natural enzymatic catalysis is governed by the precise three-dimensional (3D) coordination environments of active sites to create spatially optimized reaction centers. Inspired by this biological architecture, we engineered a biomimetic enzyme mimicking heme peroxidase (POD) functionality to reduce overreliance on transition metals in advanced water treatment. Integrating the natural cofactor hemin with C3N4 nanosheets via π-π stacking and axial Fe-N coordination─mimicking amino acid microenvironments through scalable self-assembly─we constructed a dynamic 3D catalytic center analogous to natural enzyme pockets. The synthesized biomimetic catalyst demonstrated remarkable POD-like activity enhancements─150-fold and 40-fold compared to free hemin when activated H2O2 and peroxymonosulfate (PMS), respectively. Mechanistic studies revealed that axial coordination induced nonplanar deformation of the hemin, weakening d-π conjugation between Fe d-orbitals and the porphyrin π-system. Notably, a biomimetic allosteric regulation triggered by this structural distortion was first proposed for water treatment, accelerating the rate-limiting sulfate desorption step during PMS activation. The catalyst also exhibited exceptional structural stability, and sustained performance in complex water matrices and high-salinity environments, achieving >80% pollutant removal over 150 h in continuous-flow tests. This catalytic structure design sets a benchmark for efficient biomimetic enzymes, bridging biocatalysis and synthetic catalysis, and offers scalable, nature-inspired solutions for water purification technologies.

Abstract The NASICON‐type Na 3 MnTi(PO 4 ) 3 (NMTP) cathode is a promising candidate for sodium‐ion batteries due to low cost, high capacity, and energy density. However, voltage hysteresis (from Mn/Na2‐vacancies intrinsic antisite defects, IASDs) and structural degradation (via Jahn–Teller distortion) limit its application. Herein, we propose a sodium vacancy and local coordination coupling strategy involving low‐valent ion doping to trigger charge compensation, thereby reducing the initial Na vacancy concentration and activating additional Na2 sites to suppress IASDs formation. Furthermore, the reconstructed Mn─O coordination environment enhances MnO 6 symmetry, mitigating Jahn–Teller distortion. The low‐cost Fe 2+ was introduced into the NMTP lattice, forming the Na 3+2x MnTi 1‐x Fe x (PO 4 ) 3 system. DFT calculations, ex situ XANES, and ssNMR analyses reveal a synergistic mechanism involving reduced vacancy concentration and stabilized MnO 6 symmetry, increasing IASD formation energy and improving structural stability, effectively suppressing both voltage hysteresis and Jahn–Teller distortion. The optimized Na 3.2 MnTi 0.9 Fe 0.1 (PO 4 ) 3 cathode demonstrates exceptional electrochemical performance, including high specific capacity (174.2 mAh g −1 at 0.1 C), outstanding rate capability (125.5 mAh g −1 at 20 C), and long‐term cycling stability (85% retention after 2000 cycles at 5 C). This work provides new insights into the design of high energy density, long‐lifespan sodium‐ion batteries through sodium vacancy and coordination engineering.

Abstract Transition metal oxides, with abundant uncoordinated O atoms and oxygen‐rich nature, show promise for chlorine evolution reaction (CER). However, their oxygen species exist in two distinct coordination environments (tetrahedral O tet versus octahedral O oct ), and their distinct roles and contributions as active sites remain unclear. Facet dependent Co 3 O 4 electrocatalysts are investigated to probe how crystallographic orientation governs stability and to identify dominant active sites. The (110)‐faceted Co 3 O 4 demonstrates exceptional stability over 80 h at 10 mA cm −2 and shows only 4.7% activity loss after 1000 cyclic voltammetry cycles due to its abundant O oct , low surface energy, and optimal adsorption capacity. Distribution of relaxation times analysis and theoretical calculations reveal that O oct has the lowest physical diffusion resistance and suitable adsorption of intermediates, thus improving CER activity. This work clarifies the distinct roles of O oct and O tet in CER catalysis, offering new design principles for efficient CER electrocatalysts.