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In this work, carbon submicron fiber composites loaded with a cobalt-ferric alloy and cobalt-ferric binary metal compounds were prepared by electrospinning and high temperature annealing using cobalt-ferric acetone and ferric acetone as precursors and polyacrylonitrile as a carbon source. The phase transformation mechanism of the carbon submicron fiber-supported Co-Fe bimetallic compound during high temperature annealing was investigated. The electrochemical properties of the carbon submicron fiber-supported Co-Fe alloy and Co-Fe oxide self-supported electrode materials were investigated. The results show that at 138 °C, the heterogeneous submicron fibers of cobalt acetylacetonate and acetylacetone iron began to decompose and at 200 °C, CoFe2O4 was generated in the fiber. As the annealing temperature increases further, some metal compounds in the carbon fiber are reduced to CoFe2O4 alloy, and two phases of CoFe2O4 and CoFe-Fe-alloy exist in the fiber. After 200 cycles, the specific capacity of CF-P500 is 500 mAh g−1. The specific capacity of the composite carbon submicron fiber electrode material can be significantly improved by the introduction of CoFe2O4. When the binary metal oxides are used as electrode materials for lithium-ion batteries, alloy dealloying and conversion reactions can occur at the same time in the reverse process of lithium intercalation, the two reactions form a synergistic effect, and the cobalt-iron alloy in the material increases the electrical conductivity. Therefore, the carbon submicron fiber loaded with CoFe2O4/CoFe has an excellent electrochemical performance.

Molecularly well-defined homogeneous catalysts are known for a wide variety of chemical transformations. The effect of small changes in molecular structure can be studied in detail and used to optimize many processes. However, many industrial processes require heterogeneous catalysts because of their stability, ease of separation and recyclability, but these are more difficult to control on a molecular level. Here, we describe the conversion of homogeneous cobalt complexes into heterogeneous cobalt oxide catalysts via immobilization and pyrolysis on activated carbon. The catalysts thus produced are useful for the industrially important reduction of nitroarenes to anilines. The ligand indirectly controls the selectivity and activity of the recyclable catalyst and catalyst optimization can be performed at the level of the solution-phase precursor before conversion into the active heterogeneous catalyst. Pyrolysis of defined nitrogen-ligated cobalt acetate complexes onto a commercial carbon support transforms the complexes into heterogeneous Co 3 O 4 materials. These reusable non-noble-metal catalysts are highly selective for the industrially important hydrogenation of structurally diverse and functionalized nitroarenes to anilines.

Li[LixNiyMnzCo1−x−y−z]O2 (lithium-rich NMCs) are benchmark cathode materials receiving considerable attention due to the abnormally high capacities resulting from their anionic redox chemistry. Although their anionic redox mechanisms have been much investigated, the roles of cationic redox processes remain underexplored, hindering further performance improvement. Here we decoupled the effects of nickel and cobalt in lithium-rich NMCs via a comprehensive study of two typical compounds, Li1.2Ni0.2Mn0.6O2 and Li1.2Co0.4Mn0.4O2. We discovered that both Ni3+/4+ and Co4+, generated during cationic redox processes, are actually intermediate species for triggering oxygen redox through a ligand-to-metal charge-transfer process. However, cobalt is better than nickel in mediating the kinetics of ligand-to-metal charge transfer by favouring more transition metal migration, leading to less cationic redox but more oxygen redox, more O2 release, poorer cycling performance and more severe voltage decay. Our work highlights a compositional optimization pathway for lithium-rich NMCs by deviating from using cobalt to using nickel, providing valuable guidelines for future high-capacity cathode design.Lithium-rich nickel manganese cobalt oxide cathodes are widely explored due to their high capacities related to their anionic redox chemistry. A compositional optimization pathway for these materials investigating the variation of using cobalt and nickel now provides valuable guidelines for future high-capacity cathode design.

Modern magnetic-memory technology requires all-electric control of perpendicular magnetization with low energy consumption. While spin–orbit torque (SOT) in heavy metal/ferromagnet (HM/FM) heterostructures 1 – 5 holds promise for applications in magnetic random access memory, until today, it has been limited to the in-plane direction. Such in-plane torque can switch perpendicular magnetization only deterministically with the help of additional symmetry breaking, for example, through the application of an external magnetic field 2 , 4 , an interlayer/exchange coupling 6 – 9 or an asymmetric design 10 – 14 . Instead, an out-of-plane SOT 15 could directly switch perpendicular magnetization. Here we observe an out-of-plane SOT in an HM/FM bilayer of L 1 1 -ordered CuPt/CoPt and demonstrate field-free switching of the perpendicular magnetization of the CoPt layer. The low-symmetry point group (3 m 1) at the CuPt/CoPt interface gives rise to this spin torque, hereinafter referred to as 3 m torque, which strongly depends on the relative orientation of the current flow and the crystal symmetry. We observe a three-fold angular dependence in both the field-free switching and the current-induced out-of-plane effective field. Because of the intrinsic nature of the 3 m torque, the field-free switching in CuPt/CoPt shows good endurance in cycling experiments. Experiments involving a wide variety of SOT bilayers with low-symmetry point groups 16 , 17 at the interface may reveal further unconventional spin torques in the future. Spin–orbit torque in heavy metal/ferromagnet heterostructures is promising for all-electric control of magnetic memory, but has so far required an additional symmetry breaking in the design to switch perpendicular magnetization. Instead, a low symmetry at the interface can give rise to out-of-plane spin torque and switch the magnetization deterministically.

All-electric switching of perpendicular magnetization is a prerequisite for the integration of fast, high-density, and low-power magnetic memories and magnetic logic devices into electric circuits. To date, the field-free spin-orbit torque (SOT) switching of perpendicular magnetization has been observed in SOT bilayer and trilayer systems through various asymmetric designs, which mainly aim to break the mirror symmetry. Here, we report that the perpendicular magnetization of Co x Pt 100- x single layers within a special composition range (20 <  x  < 56) can be deterministically switched by electrical current in the absence of external magnetic field. Specifically, the Co 30 Pt 70 shows the largest out-of-plane effective field efficiency and best switching performance. We demonstrate that this unique property arises from the cooperation of two structural mechanisms: the low crystal symmetry property at the Co platelet/Pt interfaces and the composition gradient along the thickness direction. Compared with that in bilayers or trilayers, the field-free switching in Co x Pt 100- x single layer greatly simplifies the SOT structure and avoids additional asymmetric designs. One challenge for spin-based electronics is the controlled and reliable switching of magnetization without magnetic fields. Here, Liu et al investigate a variety of compositions of CoPt, and determine the specific composition to maximize switching performance, potentially simplifying device design.

The cobalt complexes HCo(CO)4 and HCo(CO)3(PR3) were the original industrial catalysts used for the hydroformylation of alkenes through reaction with hydrogen and carbon monoxide to produce aldehydes. More recent and expensive rhodium-phosphine catalysts are hundreds of times more active and operate under considerably lower pressures. Cationic cobalt(II) bisphosphine hydrido-carbonyl catalysts that are far more active than traditional neutral cobalt(I) catalysts and approach rhodium catalysts in activity are reported here. These catalysts have low linear-to-branched (L:B) regioselectivity for simple linear alkenes. However, owing to their high alkene isomerization activity and increased steric effects due to the bisphosphine ligand, they have high L:B selectivities for internal alkenes with alkyl branches. These catalysts exhibit long lifetimes and substantial resistance to degradation reactions.

Lower olefins are hydrocarbons that are widely used in the chemical industry, and can be generated from syngas by the ‘Fischer–Tropsch to olefins’ process; here, a new catalyst is described that can generate lower olefins from syngas with high selectivity, with little formation of undesirable methane. Lower olefines—and not much methane—from biomass The lower olefins—chiefly ethylene, propylene and butylene—are starting materials for many plastics and other industrial products. They are usually obtained by cracking hydrocarbon feedstocks, so as petroleum reserves become depleted the urgency to switch to alternative feedstocks such as biomass increases. The 'Fischer–Tropsch to olefins' (FTO) process produces lower olefines from syngas—a mixture of hydrogen and carbon monoxide derived from biomass, coal and natural gas—but at the same time produces large amounts of unwanted methane. Here Liangshu Zhong and colleagues describe a new catalyst for the FTO conversion. Formed from cobalt carbide nanoprisms, the catalyst is active in mild reaction conditions, is highly selective for lower olefins and, critically, produces very little methane. Lower olefins—generally referring to ethylene, propylene and butylene—are basic carbon-based building blocks that are widely used in the chemical industry, and are traditionally produced through thermal or catalytic cracking of a range of hydrocarbon feedstocks, such as naphtha, gas oil, condensates and light alkanes 1 , 2 . With the rapid depletion of the limited petroleum reserves that serve as the source of these hydrocarbons, there is an urgent need for processes that can produce lower olefins from alternative feedstocks 3 , 4 , 5 , 6 , 7 , 8 , 9 . The ‘Fischer–Tropsch to olefins’ (FTO) process has long offered a way of producing lower olefins directly from syngas—a mixture of hydrogen and carbon monoxide that is readily derived from coal, biomass and natural gas 3 , 4 , 5 , 6 , 7 . But the hydrocarbons obtained with the FTO process typically follow the so-called Anderson–Schulz–Flory distribution, which is characterized by a maximum C 2 –C 4 hydrocarbon fraction of about 56.7 per cent and an undesired methane fraction of about 29.2 per cent (refs 1 , 10 , 11 , 12 ). Here we show that, under mild reaction conditions, cobalt carbide quadrangular nanoprisms catalyse the FTO conversion of syngas with high selectivity for the production of lower olefins (constituting around 60.8 per cent of the carbon products), while generating little methane (about 5.0 per cent), with the ratio of desired unsaturated hydrocarbons to less valuable saturated hydrocarbons amongst the C 2 –C 4 products being as high as 30. Detailed catalyst characterization during the initial reaction stage and theoretical calculations indicate that preferentially exposed {101} and {020} facets play a pivotal role during syngas conversion, in that they favour olefin production and inhibit methane formation, and thereby render cobalt carbide nanoprisms a promising new catalyst system for directly converting syngas into lower olefins.

Metalloradical catalysis (MRC) exploits the metal-centred radicals present in open-shell metal complexes as one-electron catalysts for the generation of metal-stabilized organic radicals—key intermediates that control subsequent one-electron homolytic reactions. Cobalt(II) complexes of porphyrins, as stable 15e-metalloradicals with a well-defined low-spin d7 configuration, have dominated the ongoing development of MRC. Here, to broaden MRC beyond the use of Co(II)-based metalloradical catalysts, we describe systematic studies that establish the operation of Fe(III)-based MRC and demonstrate an initial application for asymmetric radical transformations. Specifically, we report that five-coordinate iron(III) complexes of porphyrins with an axial ligand, which represent another family of stable 15e-metalloradicals with a d5 configuration, are potent metalloradical catalysts for olefin cyclopropanation with different classes of diazo compounds via a stepwise radical mechanism. This work lays a foundation and mechanistic blueprint for future exploration of Fe(III)-based MRC towards the discovery of diverse stereoselective radical reactions.Cobalt(II) complexes of porphyrins have dominated the development of metalloradical catalysts. Now it has been shown that five-coordinate iron(III) complexes of porphyrins with an axial ligand are also potent metalloradical catalysts for olefin cyclopropanation. They are shown to react with different classes of diazo compounds via a stepwise radical mechanism.

A novel cobalt oxide LaCo6O11 has been synthesized under high pressure of 8 GPa, and its crystal structure and magnetic property have been investigated. Rietveld analysis using synchrotron X‐ray powder diffraction data demonstrates that LaCo6O11 crystallizes in the magnetoplumbite‐derived structure as well as A2+Co6O11 (A = Ca, Sr, Ba). Bond valence sum (BVS) calculation exhibits a substantial decrease in BVS of octahedral Co sites with itinerant electrons, whereas BVS at trigonal bipyramidal Co site with localized electrons is unchanged, indicating that the doped electrons are predominantly injected into the Co sites with electric conductivity. Magnetization measurement shows that the magnetic ground state of LaCo6O11 is similar to the antiferromagnetic‐like one in CaCo6O11. However, the absence of a field‐induced ferrimagnetic transition in LaCo6O11 indicates the robustness of the antiferromagnetic‐like ground state. The difference in the magnetic state under the external magnetic field between LaCo6O11 and CaCo6O11 is attributed to the suppression of the ferromagnetic RKKY interaction because of the reduction in hole carrier density by La3+ substitution for Ca2+. A novel magnetoplumbite‐derived oxide LaCo6O11 has been synthesized under high pressure of 8 GPa.

The study of the stereochemistry of organic sulfur compounds has been ongoing for over a century, with S-chirogenic pharmacophores playing an essential role in drug discovery within bioscience and medicinal chemistry. Traditionally, the synthesis of sulfinamides featuring stereogenic sulfur(IV) centers involves a complex, multistep process that often depends on chiral auxiliaries or kinetic resolution. Here, we introduce an effective and versatile method for synthesizing diverse classes of S-chirogenic sulfinamides through selective aryl and alkenyl addition to sulfinylamines. This process is catalysed by a chiral nickel or cobalt complex under reductive conditions, and eliminating the need for preformed organometallic reagents. The method facilitates the incorporation of a diverse array of aryl and alkenyl halides at the sulfur position, enabling their integration into various biologically significant sulfur pharmacophores. Our detailed mechanistic investigations and density functional theory calculations provide insights into the reaction pathway, particularly highlighting the enantiocontrol mode during addition process. S-chirogenic pharmacophores play an essential role in drug discovery within bioscience and medicinal chemistry. Here, the authors report a methodology for synthesizing diverse classes of S-chirogenic sulfinamides through asymmetric reductive addition of aryl and alkenyl halides to sulfinylamines via common-Earth-metal catalysis.