Cobalt Metal Research Articles

Progress in Cobalt Complexes for Enabling Asymmetric Hydrogenation, H2 Production Catalysis and Alkene/Alkyne Hydro‐functionalization: A Review

AbstractThe use of hydrogen as an alternate clean fuel over conventional fuels, in addition to its role in chemical industries giving rise to useful products like hydrocarbons, has been the subject of research for many years. The need for hydrogen gas production methods has ever since been in demand. This review offers a comprehensive exploration of applications of cobalt complexes in asymmetric hydrogenation, H2 production catalysis and the hydro‐functionalization of alkenes and alkynes. Cobalt metal stands out, particularly due to its distinctive involvement in potential single‐electron processes. The main objective of this review is to provide an insight into the role of cobalt‐based coordination complexes as catalysts in hydrogenation reactions. It delves into models for enantio‐induction and extensively investigates the role of cobalt complexes in hydrogen evolution and associated reactions. Cobalt selection as the central metal is attributed to its beneficial (II)/(III) redox couple state, which proves valuable in hydride transfer reactions. While the review is structured based on substrate types, its core focus lies in the mechanism‐driven exploration of catalytic systems. These catalytic systems exhibit versatility in facilitating the hydrogenation and hydro‐functionalization of various types of double bonds through the utilization of tridentate ligands.

Heterostructured nickel–cobalt metal alloy and metal oxide nanoparticles as a polysulfide mediator for stable lithium–sulfur full batteries with lean electrolyte

AbstractBatteries that utilize low‐cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density. However, building a lithium–sulfur (Li–S) full battery by controlling the electrolyte volume generally produces low practical energy because of the limited electrochemical Li–S redox. Herein, the high energy/high performance of a Li–S full battery with practical sulfur loading and minimum electrolyte volume is reported. A unique hybrid architecture configured with Ni–Co metal alloy (NiCo) and metal oxide (NiCoO2) nanoparticles heterogeneously anchored in carbon nanotube‐embedded self‐standing carbon matrix is fabricated as a host for sulfur. This work demonstrates the considerable improvement that the hybrid structure's high conductivity and satisfactory porosity promote the transport of electrons and lithium ions in Li–S batteries. Through experimental and theoretical validations, the function of NiCo and NiCoO2 nanoparticles as an efficient polysulfide mediator is established. These particles afford polysulfide anchoring and catalytic sites for Li–S redox reaction, thus improving the redox conversion reversibility. Even at high sulfur loading, the nanostructured Ni–Co metal alloy and metal oxide enable to have stable cycling performance under lean electrolyte conditions both in half‐cell and full‐cell batteries using a graphite anode.

Cobalt and copper-based metal-organic frameworks synthesis and their supercapacitor application

In this study, two different metal-organic frameworks (MOFs) were synthesized using copper and cobalt metal ions with benzenedicarboxylic acid (bdc) as a common ligand. The prepared MOFs were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectroscopy. Also, the electrochemical characteristics were analyzed using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy methods. Structural characterizations indicate that Co-bdc MOF is composed of three-dimensional non-uniform colloids and Cu-bdc MOF has a regular three-dimensional cuboidal structure, possessing good crystalline structure. The Cu-bdc MOF exhibited a maximum specific capacitance of 171 F/g, while Co-bdc MOF showed 368 F/g at the current density of 1 A/g. The solution resistance for the Co-bdc MOF was 0.09 Ω in comparison to 1.25 Ω for the Cu-bdc MOF. Also, the Co-bdc MOF demonstrated better cycling performance by retaining 85 % of its capacity after 2000 charge-discharge cycles. In contrast, the stability of the Cu-bdc MOF was lower, with only 78 % retention in capacity. Conclusively, the Co-bdc MOF demonstrated superior specific capacitance, lower resistance, and enhanced cyclic stability in 3 M KOH electrolyte system.

Synthesis and Spectroscopic Characterization of Schiff Base Metal Complexes, Biological Activity, and Molecular Docking Studies.

New cobalt(II), copper(II), and zinc(II) Schiff metal complexes were synthesized by the condensation reaction of 4-nitrobenzene-1,2-diamine with 3-4-(diethylamino)-2-hydroxybenzaldehyde. Fourier transform infrared, nuclear magnetic resonance, ultraviolet-visible, electron paramagnetic resonance, and high-resolution electrospray ionization mass spectrometry and powder X-ray diffraction were used to characterize the synthesized H2L and its metal complexes. Conductance measurements, magnetic moment estimation, and metal estimation have all been determined and discussed. The electrochemical properties of the synthesized compounds have been determined and discussed using cyclic voltammetry. The molecular structures of H2L and its metal complexes have been optimized using the B3LYP functional and the 6-31G (d,p) basis set, and their parameters have been discussed. The quantum chemical properties of these synthesized compounds have been predicted through charge distribution and molecular orbital analysis. The biological properties of the synthesized compounds' antioxidant, antifungal, and antibacterial activity have been studied and discussed. Furthermore, H2L and its complexes have been docked with HER2-associated target proteins in breast cancer.

Enhanced photocatalytic degradation by higher exposure of {110} facet and surface oxygen vacancies of BiOBr through cobalt doping strategy

Transition metal cobalt doped BiOBr (Co-BOB) was successfully synthesized by using hydrothermal method. The optimized Co-BOB achieved a remarkable rhodamine B degradation rate of 97 % in 30 min under visible light irradiation when initial concentration was 80 mg·L−1. Satisfactory removal efficiency was also observed under ambient sunlight irradiation and various water conditions. The cobalt doping strategy induced abundant surface oxygen vacancies formation (43.22 %) and resulted in an increasing exposure of {110} facets. The photosensitization and photocatalytic activities of Co-BOB significantly enhanced comparing with that of pure BiOBr. The synergy of Co doping and oxygen vacancies also induced the formation of a new band structure in Co-BOB. The synergistic effect promoted the efficient separation of photogenerated electrons and holes. By combining with density functional theory calculation, the RhB photocatalytic degradation mechanism by Co-BOB was proposed.

A facile strategy of designing a new crystalline cobalt metal–organic framework as a new efficient and robust heterogeneous catalyst for olefin oxidation reaction

A novel three-dimensional (3D) metal-organic compound Co3(BDC)3(DMF)2(H2O)4.2DMF (DMF= N,N-dimethylformamide; BDC= 1,4-benzenedicarboxylate) (Co-BDC (1)) has been synthesized under solvothermal method using Co2+ salt and BDC as a rigid ligand. The material was structurally characterized by single-crystal X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR), thermogravimetric (TGA), inductively coupled plasma (ICP), and elemental (CHN) techniques. Oxidation of some olefins was evaluated with tert‑butyl hydroperoxide (TBHP) in acetonitrile in the presence of Co-BDC (2) (activated Co-BDC (1)) as a heterogeneous catalyst. Among the substrates used for the oxidation reaction, desirable conversions of 97 %, 81.6 %, and 76 % were obtained for cyclooctene, 1-hexene, and norbornene, respectively. Finally, the catalyst was recycled and reused (four times) without a remarkable decrease in the catalytic activity.

Preparation and properties of bimetallic Co/Cu ZIF-67 for electrochemical application

Efforts to enhance the electrochemical properties of materials have become the focus of numerous studies because these properties are essential in various fields of application. Zeolitic imidazole framework-67 (ZIF-67) is a type of metal-organic framework (MOFs) expected to demonstrate excellent performance in electrochemical applications due to its numerous distinct properties. Consequently, various strategies and techniques have been developed to improve the electrochemical performance of ZIF-67. In this study, we employed bimetallic ZIF-67 constructed with cobalt (Co) and copper (Cu) metal ions within the imidazole frameworks. The use of bimetal is expected to increase conductivity and fine-tune the physicochemical properties of ZIF-67. Using coprecipitation methods, we synthesized both single-metal and bimetallic ZIF-67 and compared their characterizations. The addition of Cu metal ions does not alter the materials phase, ensuring compatibility with the single-metal ZIF-67 structure. However, the rhombic dodecahedron morphology of ZIF-67 shifts from a smooth to a concave and rough surface in Co/Cu ZIF-67. Furthermore, Co/Cu ZIF-67 exhibits higher peak current on their cyclic voltammetry (CV) curve by 46.15 µA. The results effectively illustrate the advantages of bimetal on ZIF-67 properties and performance. Finally, this study succesfully briefly demonstrate the potential development of Co/Cu-based ZIF-67 for various electrochemical applications.

Recycling potential of cobalt metal from end-of-life new energy passenger vehicles in China.

The growing demand for new energy vehicles (NEVs) has resulted in a corresponding increase in demand for cobalt as a critical material. It is crucial to estimate the cobalt resource recycling potential of China's NEV industry to ensure a balance between the supply and demand for cobalt metal minerals. This article is based on using the historical data of the new energy passenger vehicle (NEPV) sales volume from 2013 to 2022 to estimate the NEPV sales volume from 2023 to 2035. On this basis, the Weibull distribution was used to analyse the different sales scenarios (low sales and high sales) of NEPVs in China, and the recycling potential of cobalt metal in NEPVs was evaluated under three battery life scenarios (8, 10 and 12 years) from 2023 to 2035. Based on the above scenarios, in 2035, the greatest recycling potential of cobalt is predicted to be 166.9 kilotonnes, with economic values of CNY 49.01-94.60 billion. Moreover, the extent to which the recycling potential of cobalt can cover the market demand for NEPVs was analysed. Our analysis concluded that recycling cobalt as a secondary supply has emerged as a necessary solution to supplement the primary supply, which can make a significant contribution to alleviating the pressure of the supply and demand.

Amorphous Metallic Cobalt-Based Organophosphonic Acid Compounds as Novel Photocatalysts to Boost Photocatalytic CO2 Reduction

Photocatalytic carbon dioxide conversion is a promising method for generating carbon fuels, in which the most important thing is to adjust the catalyst material to improve the photocatalytic efficiency and selectivity to conversion products, but it is still very challenging. In order to enhance the efficiency of CO2 photoreduction, it is important to develop an appropriate photocatalyst. The present study focuses on developing a simple and effective hydrothermal reaction treatment to improve the catalytic efficiency of transition metal cobalt (Co) and organophosphonates. Photoexcited charge carriers are separated and transferred efficiently during this treatment, which enhances CO2 chemisorption. Under visible light exposure, the best performing catalyst, CoP-4, showed 2.4 times higher activity than Co3O4 (19.90 μmol h−1 g−1) for reducing CO2 into CO, with rates up to 47.16 μmol h−1 g−1. This approach provides a viable route to enhancing the efficiency of CO2 photoreduction.

Controllable Assembly of Highly Oxidized Cobalt on Graphdiyne Surface for Efficient Conversion of Nitrogen into Nitric Acid

AbstractThe manufacture of nitric acid (HNO3) consumes large amounts of energy and causes serious environmental pollution. Electrochemical synthesis is regarded as a key way to eliminate carbon emissions from the chemicals industry. The selective electrosynthesis of HNO3 from nitrogen was achieved by controllable assembly of cobalt metal on graphdiyne surface using a powerful tool of electrochemistry at ambient conditions. As an advanced material, graphdiyne (GDY) has a large conjugated structure on its surface and is rich in sp‐C triple bond skeleton, which can achieve strong interaction with metal atoms, resulting in incomplete charge transfer between graphdiyne and cobalt atoms. The experimental and theoretical calculation results show that the highly oxidized cobalt on graphdiyne (HOCo/GDY) can selectively and efficiently activate and convert the nitrogen into the key intermediate *NO, which promotes the efficient overall conversion performance of nitrogen to nitric acid. Thus, the highest nitric acid yield (192.0 μg h−1 mg−1) and Faradaic efficiency (21.5 %) were achieved at low potentials.

Controllable Assembly of Highly Oxidized Cobalt on Graphdiyne Surface for Efficient Conversion of Nitrogen into Nitric Acid.

The manufacture of nitric acid (HNO3 ) consumes large amounts of energy and causes serious environmental pollution. Electrochemical synthesis is regarded as a key way to eliminate carbon emissions from the chemicals industry. The selective electrosynthesis of HNO3 from nitrogen was achieved by controllable assembly of cobalt metal on graphdiyne surface using a powerful tool of electrochemistry at ambient conditions. As an advanced material, graphdiyne (GDY) has a large conjugated structure on its surface and is rich in sp-C triple bond skeleton, which can achieve strong interaction with metal atoms, resulting in incomplete charge transfer between graphdiyne and cobalt atoms. The experimental and theoretical calculation results show that the highly oxidized cobalt on graphdiyne (HOCo/GDY) can selectively and efficiently activate and convert the nitrogen into the key intermediate *NO, which promotes the efficient overall conversion performance of nitrogen to nitric acid. Thus, the highest nitric acid yield (192.0 μg h-1 mg-1 ) and Faradaic efficiency (21.5 %) were achieved at low potentials.

Toxic textiles: Potential health risks associated with toxic chemicals in clothing

Toxic textiles: Potential health risks associated with toxic chemicals in clothing Maria A. Muñoz and Pamela J. Lein from the University of California, Davis, focus on the potential health risks associated with toxic chemicals in clothing. In 2011, approximately 800 of 3,000 Alaska Airlines attendants began reporting various symptoms, including skin rashes, itchy eyes, and coughing. These complaints coincided with the introduction of new uniforms earlier that year and would continue until February 2014, when the clothing was recalled. Laboratory analyses of the attendants’ uniforms detected various toxic chemicals, including metals (lead, chromium, and cobalt) and known skin irritants, such as toluene, tributyl phosphate, and dimethyl fumarate, in the cloth used to make the uniforms.

Dual interfacing with metallic cobalt boosts the electron shuttle of CdS-carbide nanoassemblies

Harnessing accelerated interfacial redox, thus boosting charge separation, is of great importance in photocatalytic solar hydrogen generation. In effect, nanoassembling non-noble metallic phases in CdS-based systems and elucidating their role in photocatalysis hold the key to eventually boosting electron shuttle in the field. Here we combine an efficient in-situ exsoluted metallic Co0 nanoparticles on a carbides matrix (CMG) with CdS (CdS@CoCMG) for photogeneration of hydrogen. The metallic cobalt phase exhibits strong binding at the CdS-carbide dual interfaces, forming the accelerated “electron converter” mechanism validated by charge transfer kinetics and achieving two orders of magnitude faster hydrogen production (44.42 mmol g−1 h−1) relative to CdS (0.43 mmol g−1 h−1). We propose that the unique catalyst configuration enable the directional electron-relay photocatalysis via harnessing interfaces between Co0 phase, carbides, and CdS clusters, which eventually boosts the redox process and charge separation of the integrated system, leading to high H2 production rates in the suspension.

Atomic-scale understanding of the impact of CoO phase in cobalt-catalyzed Fischer-Tropsch synthesis: A combined computational and experimental study

In cobalt-catalyzed Fischer-Tropsch synthesis (FTS), the active metallic cobalt phase always suffers from oxidation under FTS reaction conditions, leading to the coexistence of metallic cobalt and cobalt oxide (CoO) phases. However, there still exist contradictory views on the impact of CoO phase in FTS. Some researchers proposed that the oxidation of metallic Co to CoO causes the deactivation of cobalt-based FTS catalysts, while some held the view that CoO phase could act as the potential active phase in FTS. In this study, by combining theoretical calculations and experiments, we systematically investigated the fundamental FTS reactions including CO adsorption and activation, C-C coupling, and CxHy hydrogenation on CoO phase, and compared them with those on metallic cobalt phase, aiming at identifying the exact role of CoO, understanding how CoO influences the activity and selectivity, and unraveling the intrinsic mechanism that determines the catalytic behaviors of CoO phase in FTS. The results reveal that the CoO(200) crystal facet is the dominantly exposed surface structure for CoO phase under FTS reaction conditions. The d-band center of CoO(200) surface shifts downward in comparison with that of active metallic Co surface, which causes difficulties in adsorbing and activating CO and gives rise to high energy barriers for the dissociation of C-O bond. This determines the inactive nature of CoO phase in FTS reaction. As for the product selectivity, the CoO(200) surface restricts the C-C chain growth due to its higher barriers for C-C coupling, facile desorption ability for light olefins, and lower energy barrier for CH4 formation compared with metallic cobalt, and consequently leads to the loss of selectivity to C5+ hydrocarbons and enhancement of selectivity to light olefins and undesired methane. Moreover, a strong linear relationship between the experimental observed selectivity change and the DFT-calculated energy difference of CoO and metallic cobalt phases was found, validating the DFT-calculated results. This study provides a comprehensive understanding of the nature and intrinsic catalytic behaviors of CoO phase in cobalt-catalyzed FTS.

CO2 hydrogenation over Fe-Co bimetallic catalysts with tunable selectivity through a graphene fencing approach

Tuning CO2 hydrogenation product distribution to obtain high-selectivity target products is of great significance. However, due to the imprecise regulation of chain propagation and hydrogenation reactions, the oriented synthesis of a single product is challenging. Herein, we report an approach to controlling multiple sites with graphene fence engineering that enables direct conversion of CO2/H2 mixtures into different types of hydrocarbons. Fe-Co active sites on the graphene fence surface present 50.1% light olefin selectivity, while the spatial Fe-Co nanoparticles separated by graphene fences achieve liquefied petroleum gas of 43.6%. With the assistance of graphene fences, iron carbides and metallic cobalt can efficiently regulate C-C coupling and olefin secondary hydrogenation reactions to achieve product-selective switching between light olefins and liquefied petroleum gas. Furthermore, it also creates a precedent for CO2 direct hydrogenation to liquefied petroleum gas via a Fischer-Tropsch pathway with the highest space-time yields compared to other reported composite catalysts.

High-performance Ni-free sustainable cathode Na0.67Mg0.05Fe0.1Mn0.85O2 for sodium-ion batteries.

Having in mind the remarkable economic and environmental issues involved in the presence of nickel and cobalt metals in electrode compositions, new Na0.67Mg0.05Fe0.1NixMn0.85-xO2 (x=0.0, 0.05, 0.1, 0.15) with a P2 type layered structure, are synthesized to be essayed as positive electrodes in sodium-ion batteries. The sol-gel route here proposed favors the obtention of highly pure and crystalline samples with a homogeneous distribution of the constituting elements. Both galvanostatic and voltammetric tests reveal a superior electrochemical behavior for the Ni-free sample, which delivers 94 mA h g-1 at 5C. This excellent performance is associated with a good kinetic response in terms of low charge and discharge hysteresis, high Na+ diffusivity, and low cell resistance. Ex-situ measurements evidenced the combined contribution of both the reversible electrolyte insertion and the formation of peroxo species. These advantageous properties allow this electrode to reach a remarkable behavior when is cycled either to low temperatures or high rates.

Oxidative response to accumulation of trace metals in tissue of two bivalves, the Asian green mussel Perna viridis and the blood cockle Tegillarca granosa, living in Pattani Bay, Thailand.

Using bivalves to indicate aquatic pollutants was favorable for discerning the negative effects of high levels of metal accumulation in tissue. We investigated the correlation between trace metal accumulation and the tissue oxidative response of two bivalves. The Asian green mussel Perna viridis and the blood cockle Tegillarca granosa were sampled along with seawater and sediments from three locations around Pattani Bay, Thailand. Accumulation of nine trace metals (cadmium, cobalt, copper, chromium, nickel, manganese, iron, zinc, and lead) in seawater, sediments, and tissue and the oxidative tissue response were evaluated. Metal bioaccumulation factor, biota-sediment accumulation factor, and histopathology were also indicated. The present study found that P. viridis and T. granosa were macroconcentrators and bioaccumulative of cadmium, and their tissue accumulation of cadmium was strongly related to lipid peroxidation activation. Perna viridis exhibited a higher oxidative response than T. granosa, as indicated by malondialdehyde, catalase, and reduced glutathione levels. The present study indicated that P. viridis and T. granosa were macroconcentrators and bioaccumulative of cadmium, and their tissue accumulation of cadmium was strongly related to lipid peroxidation activation. Research has shown discernible negative effects of a high level of metal accumulation in tissue, and deformed and damaged tissues were present in the gills, digestive glands, intestines, and feet of P. viridis and T. granosa.

Two-mode sensing strategies based on tunable cobalt metal organic framework active sites to detect Hg2+

Heavy metal pollution poses a major threat to human health, and developing a user-deliverable heavy metal detection strategy remains a major challenge. In this work, two-mode Hg2+ sensing platforms based on the tunable cobalt metal-organic framework (Co-MOF) active site strategy are constructed, including a colorimetric, and an electrochemical assay using a personal glucose meter (PGM) as the terminal device. Specifically, thymine (T), a single, adaptable nucleotide, is chosen to replace typical T-rich DNA aptamers. The catalytic sites of Co-MOF are tuned competitively by the specific binding of T-Hg2+-T, and different signal output platforms are developed based on the different enzyme-like activities of Co-MOF. DFT calculations are utilized to analyze the interaction mechanism between T and Co-MOF with defect structure. Notably, the two-mode sensing platforms exhibit outstanding detection performance, with LOD values as low as 0.5 nM (colorimetric) and 3.69 nM (PGM), respectively, superior to recently reported nanozyme-based Hg2+ sensors. In real samples of tap water and lake water, this approach demonstrates an effective recovery rate and outstanding selectivity. Surprisingly, the method is potentially versatile and, by exchanging out T-Hg2+-T, can also detect Ag+. This simple, portable, and user-friendly Hg2+ detection approach shows plenty of promise for application in the future.

Synthesis, сharacterization, and сatalytic properties of GdCoO3 for dry reforming of methane

Perovskite oxides (ABO3) due to their high thermal stability and the ability to control the physico-chemical properties are considered as an alternative to traditional catalysts containing noble and transition metals. Herein, the recent research breakthroughs of GdCoO3 catalysts in experimental studies are summarized in detail. First, the perovskite-type GdCoO3 complex oxides were obtained by co-precipitation method with the various precipitators and were characterized by X-ray diffraction (XRD), low temperature nitrogen adsorption and IR spectroscopy. Physical and chemical analysis showed that the choice of precipitant doesn?t significantly affect the phase composition of the perovskites. The catalytic performance of gadolinium cobaltites was discussed. It was found that the use of cobaltites obtained by co-precipitation leads to the inhibition of the side reaction of the reverse steam reforming of carbon monoxide. Finally, the investigation of the used catalysts demonstrated the formation of Gd2O2CO3 and metallic cobalt, which indicates the nature of active centres: gadolinium is the centre of CO adsorption, while hydrogen chemisorption occurs on cobalt-sites.

Исследование механизма совместного электровосстановления ионов Dy3+ и Co2+ в эвтектическом расплаве KCl-NaCl-CsCl при 823 К

The kinetic patterns of the electroreduction of the Co2+ ion in the eutectic melt KCl-NaCl-CsCl at 823 K have been determined. It has been established that the release potentials of metallic cobalt and dysprosium on an inert tungsten electrode in the molten KCl-NaCl-CsCl system differ by approximately 1.5 V. It has been shown that with the combined content of Co2+ and Dy3+ ions in the eutectic KCl-NaCl-CsCl melt, a certain depolarization of the electroreduction of dysprosium ions takes place on the metal cobalt pre-precipitated on the tungsten electrode with the formation of intermetallic phases of different compositions based on cobalt and dysprosium. The dissolution potentials of DyxCoy intermetallic phases of different compositions were determined using switch-off chronopotentiometry.