Tailoring Metal-Oxygen Bonds Boosts Oxygen Reaction Kinetics for High-Performance Zinc-Air Batteries.

Metal-oxygen bonds significantly affect the oxygen reaction kinetics of metal oxide-based catalysts but still face the bottlenecks of limited cognition and insufficient regulation. Herein, we develop a unique strategy to accurately tailor metal-oxygen bond structure via amorphous/crystalline heterojunction realized by ion-exchange. Compared with pristine amorphous CoSnO3-y, iron ion-exchange induced amorphous/crystalline structure strengthens the Sn-O bond, weakens the Co-O bond strength, and introduces additional Fe-O bond, accompanied by abundant cobalt defects and optimal oxygen defects with larger pore structure and specific surface area. The optimization of metal-oxygen bond structure is dominated by the introduction of crystal structure and further promoted by the introduction of Fe-O bond and rich Co defect. Remarkably, the Fe doped amorphous/crystalline catalyst (Co1-xSnO3-y-Fe0.021-A/C) demonstrates excellent oxygen evolution reaction and oxygen reduction reaction activities with a smaller potential gap (ΔE = 0.687 V), and the Zn-air battery based with Co1-xSnO3-y-Fe0.021-A/C exhibits excellent output power density, cycle performance, and flexibility.

Synergistic Effect of Ni/Ni(OH)2 Core-Shell Catalyst Boosts Tandem Nitrate Reduction for Ampere-Level Ammonia Production.

Electrocatalytic reduction of nitrate to ammonia provides a green alternate to the Haber-Bosch method, yet it suffers from sluggish kinetics and a low yield rate. The nitrate reduction follows a tandem reaction of nitrate reduction to nitrite and subsequent nitrite hydrogenation to generate ammonia, and the ammonia Faraday efficiency (FE) is limited by the competitive hydrogen evolution reaction. Herein, we design a heterostructure catalyst to remedy the above issues, which consists of Ni nanosphere core and Ni(OH)2 nanosheet shell (Ni/Ni(OH)2). In situ Raman spectroscopy reveals Ni and Ni(OH)2 are interconvertible according to the applied potential, facilitating the cascade nitrate reduction synergistically. Consequently, it attains superior electrocatalytic nitrate reduction performance with an ammonia FE of 98.50 % and a current density of 0.934 A cm-2 at -0.476 V versus reversible hydrogen electrode, and exhibits an average ammonia yield rate of 84.74 mg h-1 cm-2 during the 102-hour stability test, which is highly superior to the reported catalysts tested under similar conditions. Density functional theory calculations corroborate the synergistic effect of Ni and Ni(OH)2 in the tandem reaction of nitrate reduction. Moreover, the Ni/Ni(OH)2 catalyst also possesses good capability for methanol oxidation and thus is used to establish a system coupling with nitrate reduction.

Pressure-Induced Amorphization and Crystallization of Heterophase Pd Nanostructures.

Control of structural ordering in noble metals is very important for the exploration of their properties and applications, and thus it is highly desired to have an in-depth understanding of their structural transitions. Herein, through high-pressure treatment, the mutual transformations between crystalline and amorphous phases are achieved in Pd nanosheets (NSs) and nanoparticles (NPs). The amorphous domains in the amorphous/crystalline Pd NSs exhibit pressure-induced crystallization (PIC) phenomenon, which is considered as the preferred structural response of amorphous Pd under high pressure. On the contrary, in the spherical crystalline@amorphous core-shell Pd NPs, pressure-induced amorphization (PIA) is observed in the crystalline core, in which the amorphous-crystalline phase boundary acts as the initiation site for the collapse of crystalline structure. The distinct PIC and PIA phenomena in two different heterophase Pd nanostructures might originate from the different characteristics of Pd NSs and NPs, including morphology, amorphous-crystalline interface, and lattice parameter. This work not only provides insights into the phase transition mechanisms of amorphous/crystalline heterophase noble metal nanostructures, but also offers an alternative route for engineering noble metals with different phases.

High-performance composite separators based on the synergy of vermiculite and laponite for lithium-ion batteries.

The electrochemical performance and safe operation of the separator plays an important role in lithium-ion batteries. The introduction of inorganic nanoparticles into the separators with organic matter as the matrix effectively improves the thermal stability and wettability of the composite separators, but it also blocks some pores and adversely affects the electrochemical performance. Herein, vermiculite and laponite nanoparticles are introduced into a poly(vinylidene fluoride) matrix to prepare organic-inorganic composite separators for lithium-ion batteries and the synergistic effect of the two inorganic nanofillers is explored. By adding the same amount of the two nanoparticles into the polymer matrix, the prepared separator has the highest ionic conductivity (0.72 mS cm-1) at room temperature and the lowest interfacial impedance (283 Ω). It has an initial discharge capacity of 161.2 mA h g-1 at a rate of 0.5C, a coulombic efficiency of 99.5% after 100 cycles, and a high capacity retention rate of 98.4%, which shows excellent rate performance. The results show that the two clay nanoparticles exert their respective advantages and exhibit a synergistic enhancement effect on the battery performance, which inspires new ideas for the preparation of new organic-inorganic composite separators.

Selective Epitaxial Growth of Rh Nanorods on 2H/fcc Heterophase Au Nanosheets to Form 1D/2D Rh-Au Heterostructures for Highly Efficient Hydrogen Evolution.

Phase engineering of nanomaterials (PEN) enables the preparation of metal nanomaterials with unconventional phases that are different from their thermodynamically stable counterparts. These unconventional-phase nanomaterials can serve as templates to construct precisely controlled metallic heterostructures for wide applications. Nevertheless, how the unconventional phase of templates affects the nucleation and growth of secondary metals still requires systematic explorations. Here, two-dimensional (2D) square-like Au nanosheets with an unconventional 2H/face-centered cubic (fcc) heterophase, composing of two pairs of opposite edges with 2H/fcc heterophase and fcc phase, respectively, and two 2H/fcc heterophase basal planes, are prepared and then used as templates to grow one-dimensional (1D) Rh nanorods. The effect of different phases in different regions of the Au templates on the overgrowth of Rh nanorods has been systematically investigated. By tuning the reaction conditions, three types of 1D/2D Rh-Au heterostructures are prepared. In the type A heterostructure, Rh nanorods only grow on the fcc defects including stacking faults and/or twin boundaries (denoted as fcc-SF/T) and 2H phases in two 2H/fcc edges of the Au nanosheet. In the type B heterostructure, Rh nanorods grow on the fcc-SF/T and 2H phases in two 2H/fcc edges and two 2H/fcc basal planes of the Au nanosheet. In the type C heterostructure, Rh nanorods grow on four edges and two basal planes of the Au nanosheet. Furthermore, the type C heterostructure shows promising performance toward the electrochemical hydrogen evolution reaction (HER) in acidic media, which is among the best reported Rh-based and other noble-metal-based HER electrocatalysts.

Phase-Selective Epitaxial Growth of Heterophase Nanostructures on Unconventional 2H-Pd Nanoparticles.

Heterostructured, including heterophase, noble-metal nanomaterials have attracted much interest due to their promising applications in diverse fields. However, great challenges still remain in the rational synthesis of well-defined noble-metal heterophase nanostructures. Herein, we report the preparation of Pd nanoparticles with an unconventional hexagonal close-packed (2H type) phase, referred to as 2H-Pd nanoparticles, via a controlled phase transformation of amorphous Pd nanoparticles. Impressively, by using the 2H-Pd nanoparticles as seeds, Au nanomaterials with different crystal phases epitaxially grow on the specific exposed facets of the 2H-Pd, i.e., face-centered cubic (fcc) Au (fcc-Au) on the (002)h facets of 2H-Pd while 2H-Au on the other exposed facets, to achieve well-defined fcc-2H-fcc heterophase Pd@Au core-shell nanorods. Moreover, through such unique facet-directed crystal-phase-selective epitaxial growth, a series of unconventional fcc-2H-fcc heterophase core-shell nanostructures, including Pd@Ag, Pd@Pt, Pd@PtNi, and Pd@PtCo, have also been prepared. Impressively, the fcc-2H-fcc heterophase Pd@Au nanorods show excellent performance toward the electrochemical carbon dioxide reduction reaction (CO2RR) for production of carbon monoxide with Faradaic efficiencies of over 90% in an exceptionally wide applied potential window from -0.9 to -0.4 V (versus the reversible hydrogen electrode), which is among the best reported CO2RR catalysts in H-type electrochemical cells.

Size-Dependent Phase Transformation of Noble Metal Nanomaterials.

As an important aspect of crystal phase engineering, controlled crystal phase transformation of noble metal nanomaterials has emerged as an effective strategy to explore novel crystal phases of nanomaterials. In particular, it is of significant importance to observe the transformation pathway and reveal the transformation mechanism in situ. Here, the phase transformation behavior of face-centered cubic (fcc) Au nanoparticles (fcc-AuNPs), adhering to the surface of 4H nanodomains in 4H/fcc Au nanorods, referred to as 4H-AuNDs, during in situ transmission electron microscopy imaging is systematically studied. It is found that the phase transformation is dependent on the ratio of the size of the monocrystalline nanoparticle (NP) to the diameter of 4H-AuND. Furthermore, molecular dynamics simulation and theoretical modeling are used to explain the experimental results, giving a size-dependent phase transformation diagram which provides a general guidance to predict the phase transformation pathway between fcc and 4H Au nanomaterials. Impressively, this method is general, which is used to study the phase transformation of other metal NPs, such as Pd, Ag, and PtPdAg, adhering to 4H-AuNDs. The work opens an avenue for selective phase engineering of nanomaterials which may possess unique physicochemical properties and promising applications.

Synthesis of Hierarchical 4H/fcc Ru Nanotubes for Highly Efficient Hydrogen Evolution in Alkaline Media.

Hierarchical metal nanostructures containing 1D nanobuilding blocks have stimulated great interest due to their abundant active sites for catalysis. Herein, hierarchical 4H/face-centered cubic (fcc) Ru nanotubes (NTs) are synthesized by a hard template-mediated method, in which 4H/fcc Au nanowires (NWs) serve as sacrificial templates which are then etched by copper ions (Cu2+ ) in dimethylformamide. The obtained hierarchical 4H/fcc Ru NTs contain ultrathin Ru shells (5-9 atomic layers) and tiny Ru nanorods with length of 4.2 ± 1.1 nm and diameter of 2.2 ± 0.5 nm vertically decorated on the surface of Ru shells. As an electrocatalyst for the hydrogen evolution reaction in alkaline media, the hierarchical 4H/fcc Ru NTs exhibit excellent electrocatalytic performance, which is better than 4H/fcc Au-Ru NWs, commercial Pt/C, Ru/C, and most of the reported electrocatalysts.

Polycyclic aromatic hydrocarbons in soil of the backfilled region in the Wuda coal fire area, Inner Mongolia, China.

The Wuda coal fire area in Inner Mongolia, China, has existed for 50 years and been controlled by digging and backfilling for many years. However, few studies have focused on its impact on the local environmental and ecological systems due to emission of organic contaminants from the backfilled region. In the study, topsoil samples were collected at a 0-5 cm depth from the backfilled region of the Wuda coal fire area, which has existed for five years. The samples were analyzed for 16 priority control contaminants, namely polycyclic aromatic hydrocarbons (PAHs), with a standard operation procedure and high-performance liquid chromatograph (HPLC). The results showed that the total mass contentration of 16 PAHs (∑16PAHs) ranged from 279 to 8258 µg kg-1, with an average value of 2853 ±â€¯2948 µg kg-1, which exceeded the stipulated limit for heavily contaminated soil (1000 µg kg-1). Among the 16 PAHs, 2- and 3-ring compounds accounted for more than half of ∑16PAHs. Furthermore, the results show that the main contaminants were the naphthalene (Nap), phenanthrene (Phe), pyrene (Pyr), chrysene (Chr), and benzo[b]fluoranthene (BbF) in this area (24.8%, 51.1%, 3.9%, 4.5%, and 5.7% of ∑16PAHs, respectively). The diagnostic ratio of FLA/(FLA + PYR) exceeded 0.4 and IcdP/(IcdP + BghiP) was less than 0.5, indicating gentle smoldering or spontaneous combustion of coal fire, which differs from traditional coal burning. The environmental health risk or specifically the cancer risk (CR), calculated using the surface soil of the backfilled region, was 2.84 × 10-6 for adults and 1.01 × 10-6 for children, thus indicating potential cancer risks. Therefore, PAHs pollution in the surface soil of the backfilled region in the studied coal fire area is an issue that deserves urgent attention.

Mechanism Responsible for Intercalation of Dimethyl Sulfoxide in Kaolinite: Molecular Dynamics Simulations.

Intercalation is the promising strategy to expand the interlayer region of kaolinite for their further applications. Herein, the adaptive biasing force (ABF) accelerated molecular dynamics simulations were performed to calculate the free energies involved in the kaolinite intercalation by dimethyl sulfoxide (DMSO). Additionally, the classical all atom molecular dynamics simulations were carried out to calculate the interfacial interactions between kaolinite interlayer surfaces and DMSO with the aim at exploring the underlying force that drives the DMSO to enter the interlayer space. The results showed that the favorable interaction of DMSO with both kaolinite interlayer octahedral surface and tetrahedral surface can help in introducing DMSO enter kaolinite interlayer. The hydroxyl groups on octahedral surface functioned as H-donors attracting the S=O groups of DMSO through hydrogen bonding interaction. The tetrahedral surface featuring hydrophobic property attracted the methyl groups of DMSO through hydrophobic interaction. The results provided a detailed picture of the energetics and interlayer structure of kaolinite-DMSO intercalate.

Preparation of Superhydrophilic and Underwater Superoleophobic Nanofiber-Based Meshes from Waste Glass for Multifunctional Oil/Water Separation.

The deterioration of water resources due to oil pollution, arising from oil spills, industrial oily wastewater discharge, etc., urgently requires the development of novel functional materials for highly efficient water remediation. Recently, superhydrophilic and underwater superoleophobic materials have drawn significant attention due to their low oil adhesion and selective oil/water separation. However, it is still a challenge to prepare low-cost, environmentally friendly, and multifunctional materials with superhydrophilicity and underwater superoleophobicity, which can be stably used for oil/water separation under harsh working conditions. Here, the preparation of nanofiber-based meshes derived from waste glass through a green and sustainable route is demonstrated. The resulting meshes exhibit excellent performance in the selective separation of a wide range of oil/water mixtures. Importantly, these meshes can also maintain the superwetting property and high oil/water separation efficiency under various harsh conditions. Furthermore, the as-prepared mesh can remove water-soluble contaminants simultaneously during the oil/water separation process, leading to multifunctional water purification. The low-cost and environmentally friendly fabrication, harsh-environment resistance, and multifunctional characteristics make these nanofiber-based meshes promising toward oil/water separation under practical conditions.

Recent Development of Advanced Materials with Special Wettability for Selective Oil/Water Separation.

The increasing number of oil spill accidents have a catastrophic impact on our aquatic environment. Recently, special wettable materials used for the oil/water separation have received significant research attention. Due to their opposing affinities towards water and oil, i.e., hydrophobic and oleophilic, or hydrophilic and oleophobic, such materials can be used to remove only one phase from the oil/water mixture, and simultaneously repel the other phase, thus achieving selective oil/water separation. Moreover, the synergistic effect between the surface chemistry and surface architecture can further promote the superwetting behavior, resulting in the improved separation efficiency. Here, recently developed materials with special wettability for selective oil/water separation are summarized and discussed. These materials can be categorized based on their oil/water separating mechanisms, i.e., filtration and absorption. In each section, representative studies will be highlighted, with emphasis on the materials wetting properties and innovative aspects. Finally, challenges and future research directions in this emerging and promising research field will be briefly described.

Can digital transformation change a firm's green innovation strategy? Evidence from China's heavily polluting industries.

Enterprises are facing the superimposed challenges of digitalization and greening. The shift from reactive green technology innovation (RGT) to proactive green technology innovation (PGT) has special significance for sustainable economic development. Which strategies will companies choose? Can digital transformation (DT) motivate companies to transform their green innovation strategies? Enterprises' green innovation strategy choices must be explained with regard to digitalization. The purpose of this paper is to reveal how digitalization affects the choice of green innovation strategies and to provide a realistic basis for the sustainable development of heavily polluting enterprises. We formulated a "DT-capability-strategy" theoretical framework incorporating external constraints and internal attitudes to empirically test the microdata of 505 heavily polluting enterprises. The results show that: (1) DT can shift the heavily polluting enterprises' green innovation strategies from RGT to PGT. Endogenous tests and robustness tests support this conclusion. (2) A mechanism test shows that environmental regulations cannot significantly regulate a green innovation strategy. Only a company's capabilities and attitudes can influence PGT but their effects on RGT are not statistically significant. (3) The influence of DT on green innovation strategies shows multi-dimensional heterogeneity in the digital infrastructure, scale, and innovation level of the enterprise. The conclusions provide implications for enterprises to integrate their digital and green behaviors.

Nanozymes with biomimetically designed properties for cancer treatment.

Nanozymes, as a type of nanomaterials with enzymatic catalytic activity, have demonstrated tremendous potential in cancer treatment owing to their unique biomedical properties. However, the heterogeneity of tumors and the complex tumor microenvironment pose significant challenges to the in vivo catalytic efficacy of traditional nanozymes. Drawing inspiration from natural enzymes, scientists are now using biomimetic design to build nanozymes from the ground up. This approach aims to replicate the key characteristics of natural enzymes, including active structures, catalytic processes, and the ability to adapt to the tumor environment. This achieves selective optimization of nanozyme catalytic performance and therapeutic effects. This review takes a deep dive into the use of these biomimetically designed nanozymes in cancer treatment. It explores a range of biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry. A significant focus is on tweaking the nanozyme structures to boost their catalytic performance, integrating them into complex enzyme networks similar to those in biological systems, and adjusting functions like altering tumor metabolism, reshaping the tumor environment, and enhancing drug delivery. The review also covers the applications of specially designed nanozymes in pan-cancer treatment, from catalytic therapy to improved traditional methods like chemotherapy, radiotherapy, and sonodynamic therapy, specifically analyzing the anti-tumor mechanisms of different therapeutic combination systems. Through rational design, these biomimetically designed nanozymes not only deepen the understanding of the regulatory mechanisms of nanozyme structure and performance but also adapt profoundly to tumor physiology, optimizing therapeutic effects and paving new pathways for innovative cancer treatment.

Anti-friction gold-based stretchable electronics enabled by interfacial diffusion-induced cohesion.

Stretchable electronics that prevalently adopt chemically inert metals as sensing layers and interconnect wires have enabled high-fidelity signal acquisition for on-skin applications. However, the weak interfacial interaction between inert metals and elastomers limit the tolerance of the device to external friction interferences. Here, we report an interfacial diffusion-induced cohesion strategy that utilizes hydrophilic polyurethane to wet gold (Au) grains and render them wrapped by strong hydrogen bonding, resulting in a high interfacial binding strength of 1017.6 N/m. By further constructing a nanoscale rough configuration of the polyurethane (RPU), the binding strength of Au-RPU device increases to 1243.4 N/m, which is 100 and 4 times higher than that of conventional polydimethylsiloxane and styrene-ethylene-butylene-styrene-based devices, respectively. The stretchable Au-RPU device can remain good electrical conductivity after 1022 frictions at 130 kPa pressure, and reliably record high-fidelity electrophysiological signals. Furthermore, an anti-friction pressure sensor array is constructed based on Au-RPU interconnect wires, demonstrating a superior mechanical durability for concentrated large pressure acquisition. This chemical modification-free approach of interfacial strengthening for chemically inert metal-based stretchable electronics is promising for three-dimensional integration and on-chip interconnection.

Engineering FeCo Dual Sites on Tube-on-Plate Hollow Structure for Efficient Oxygen Electroreduction.

Atomically dispersed single-atom catalysts are intriguing catalysts in the field of electrocatalysis for nearly 100% exploitation of metal atoms. However, they are still far from practical usage due to the scaling relationship limit and metal loading limit. Generation of a diatomic complex would offer superior catalytic performance through the cooperation of two neighboring atoms as active sites. Herein, Fe/Co dual atomic sites embedded in a tube-on-plate hollow structure are designed and fabricated for an efficient electrochemical oxygen reduction reaction (ORR). The unique structure composed of ultrathin nanotube building blocks dramatically maximizes the surface area for copious active site exposure. Thanks to the synergetic interaction between Fe/Co pairs, the obtained FeCo/NC exhibits outstanding ORR activity and stability in alkaline media. Furthermore, density functional theory calculations have revealed that the remarkable activity is attributed to the electron-deficient Fe sites in FeCoN6. This work may pave the way for the innovative design of highly dispersed dual-site catalysts for broader applications in the realm of electrochemical catalysis.

Emerging dynamic memristors for neuromorphic reservoir computing.

Reservoir computing (RC), as a brain-inspired neuromorphic computing algorithm, is capable of fast and energy-efficient temporal data analysis and prediction. Hardware implementation of RC systems can significantly reduce the computing time and energy, but it is hindered by current physical devices. Recently, dynamic memristors have proved to be promising for hardware implementation of such systems, benefiting from their fast and low-energy switching, nonlinear dynamics, and short-term memory behavior. In this work, we review striking results that leverage dynamic memristors to enhance the data processing abilities of RC systems based on resistive switching devices and magnetoresistive devices. The critical characteristic parameters of memristors affecting the performance of RC systems, such as reservoir size and decay time, are identified and discussed. Finally, we summarize the challenges this field faces in reliable and accurate task processing, and forecast the future directions of RC systems.

Characterizing the potentially neuronal acetylcholinesterase reactivity toward chiral pyraclofos: Enantioselective insights from spectroscopy, in silico docking, molecular dynamics simulation and per-residue energy decomposition studies.

Chiral organophosphorus agents are distributed ubiquitously in the environment, but the neuroactivity of these asymmetric chemicals to humans remains uncertain. This scenario was to explore the stereoselective neurobiological response of human acetylcholinesterase (AChE) to chiral pyraclofos at the enantiomeric scale, and then decipher the microscopic basis of enantioselective neurotoxicity of pyraclofos enantiomers. The results indicated that (R)-/(S)-pyraclofos can form the bioconjugates with AChE with a stoichiometric ratio of 1:1, but the neuronal affinity of (R)-pyraclofos (K = 6.31 × 104 M-1) with AChE was larger than that of (S)-pyraclofos (K = 1.86 × 104 M-1), and significant enantioselectivity was existed in the biochemical reaction. The modes of neurobiological action revealed that pyraclofos enantiomers were situated at the substrate binding domain, and the strength of the overall noncovalent bonds between (S)-pyraclofos and the residues was weaker than that of (R)-pyraclofos, resulting in the high inhibitory effect of (R)-pyraclofos toward the activity of AChE. Dynamic enantioselective biointeractions illustrated that the intervention of inherent conformational flexibility in the AChE-(R)-pyraclofos was greater than that of the AChE-(S)-pyraclofos, which arises from the big spatial displacement and the conformational flip of the binding domain composed of the residues Thr-64～Asn-89, Gly-122～Asp-134, and Thr-436～Tyr-449. Energy decomposition exhibited that the Gibbs free energies of the AChE-(R)-/(S)-pyraclofos were ΔG° = ï¼37.4/－30.2 kJ mol-1, respectively, and the disparity comes from the electrostatic energy during the stereoselective neurochemical reactions. Quantitative conformational analysis further confirmed the atomic-scale computational chemistry conclusions, and the perturbation of (S)-pyraclofos on the AChE's ordered conformation was lower than that of (R)-pyraclofos, which is germane to the interaction energies of the crucial residues, e.g. Tyr-124, Tyr-337, Asp-74, Trp-86, and Tyr-119. Evidently, this attempt will contribute mechanistic information to uncovering the neurobiological effects of chiral organophosphates on the body.

Synthesis of Pd3 Sn and PdCuSn Nanorods with L12 Phase for Highly Efficient Electrocatalytic Ethanol Oxidation.

The crystal phase of nanomaterials is one of the key parameters determining their physicochemical properties and performance in various applications. However, it still remains a great challenge to synthesize nanomaterials with different crystal phases while maintaining the same composition, size, and morphology. Here, a facile, one-pot, wet-chemical method is reported to synthesize Pd3 Sn nanorods with comparable size and morphology but different crystal phases, that is, an ordered intermetallic and a disordered alloy with L12 and face-centered cubic (fcc) phases, respectively. The crystal phase of the as-synthesized Pd3 Sn nanorods is easily tuned by altering the types of tin precursors and solvents. Moreover, the approach can also be used to synthesize ternary PdCuSn nanorods with the L12 crystal phase. When used as electrocatalysts, the L12 Pd3 Sn nanorods exhibit superior electrocatalytic performance toward the ethanol oxidation reaction (EOR) compared to their fcc counterpart. Impressively, compared to the L12 Pd3 Sn nanorods, the ternary L12 PdCuSn nanorods exhibit more enhanced electrocatalytic performance toward the EOR, yielding a high mass current density up to 6.22 A mgPd -1 , which is superior to the commercial Pd/C catalyst and among the best reported Pd-based EOR electrocatalysts.

Classification and carbon structural transformation from anthracite to natural coaly graphite by XRD, Raman spectroscopy, and HRTEM.

Low-weight components of coal macromolecule were subjected to pyrolysis and condensation when magmatic rock intruded into coal measure, eventually, the residual condensed aromatic components can transform into microcrystalline graphite (coaly graphite). To study the structural transformation from anthracite to natural coaly graphite, ten samples with different graphitization degrees from Xinhua and Lutang of Hunan Province, China were characterized by organic geochemical analysis, X-ray diffraction (XRD), Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). The geochemical parameters (proximate and ultimate analyses) and structural features (XRD, Raman, and HRTEM) of the series naturally graphitized coals exhibit a progressive change as the samples' locations closing to the intrusion. The series naturally graphitized coal samples were classified into four categories, including anthracite, meta-anthracite, semi-graphite, and coaly graphite. But, single parameter cannot classify the series metamorphosed coals well, multi parameters including ash free-basis volatile matter, petrographic features, and carbon structural parameters (based on XRD and Raman spectroscopy) should be considered, additionally, the lattice fringe change observed under HRTEM from anthracite to coaly graphite can verify for the classification. The relatively lower metamorphic grade samples (anthracite and meta-anthracite) have small crystalline sizes, prominent disorders, and amorphous carbon structure, whereas the crystallite structure of highest grade samples (coaly graphite) is three-dimensional crystalline order (testified by XRD and HRTEM), indicating a totally structural transformation from amorphous carbon of anthracite to highly ordered crystalline carbon of coaly graphite in the course of natural graphitization. The carbon structural evolution of coal under natural graphitization process will probably be helpful for synthetic graphite using coal to replace the expensive petroleum coke in the future.