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Electrocatalytically reducing CO2 into value-added products is a challenging but promising process. Catalysts have been proposed to reduce the potential necessary for the reaction to occur, among which single-atom alloys (SAAs) are particularly promising. Here, we employ density functional theory calculations and the computational electrode model to predict whether silver-based SAAs have the potential to be effective electrocatalysts to convert CO2 into C1 products. We take into account surface defects by using the Ag(211) surface as a model. We also verify whether the proposed materials are prone to OH poisoning or enhance the competing hydrogen evolution reaction. Our calculations predict that these materials show weak mixing between the host and the dopant, characterized by a sharp peak in the density of states near the Fermi energy, except when copper (also a coinage metal) is used as the dopant. This affects the adsorption energy of the different intermediate molecules, yielding different reaction profiles for each substrate. As non-doped silver, copper-doped SAA tends to spontaneously desorb carbon monoxide (CO) instead of proceeding with its reduction. Other elements of the fourth period (Fe, Co, and Ni) tend to bind to the CO molecule but do not favor more reduced products. These metals also tend to enhance the hydrogen evolution reaction. On the contrary, we show that the Ir and Rh dopants have significant potential as electrocatalysts, which favors the reduction of CO over its desorption while also suppressing the hydrogen evolution reaction at potentials lower than those required by copper. They have also been shown to not be prone to poisoning by OH radicals. [ABSTRACT FROM AUTHOR]

Photoredox properties of several earth-abundant light-harvesting transition metal complexes in combination with cobalt-based proton reduction catalysts have been investigated computationally to assess the fundamental viability of different photocatalytic systems of current experimental interest. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations using several GGA (BP86, BLYP), hybrid-GGA (B3LYP, B3LYP*), hybrid meta-GGA (M06, TPSSh), and range-separated hybrid (ωB97X, CAM-B3LYP) functionals were used to calculate relevant ground and excited state reduction potentials for photosensitizers, catalysts, and sacrificial electron donors. Linear energy correction factors for the DFT/TD-DFT results that provide the best agreement with available experimental reference results were determined in order to provide more accurate predictions. Among the selection of functionals, the B3LYP* and TPSSh sets of correction parameters were determined to give the best redox potentials and excited states energies, ΔEexc, with errors of ∼0.2 eV. Linear corrections for both reduction and oxidation processes significantly improve the predictions for all the redox pairs. In particular, for TPSSh and B3LYP*, the calculated errors decrease by more than 0.5 V against experimental values for catalyst reduction potentials, photosensitizer oxidation potentials, and electron donor oxidation potentials. Energy-corrected TPSSh results were finally used to predict the energetics of complete photocatalytic cycles for the light-driven activation of selected proton reduction cobalt catalysts. These predictions demonstrate the broader usefulness of the adopted approach to systematically predict full photocycle behavior for first-row transition metal photosensitizer–catalyst combinations more broadly. [ABSTRACT FROM AUTHOR]

[Display omitted] Nonaqueous Li − O 2 battery (LOB) is considered one of the most promising energy storage system due to its ultrahigh theoretical specific capacity (3500 Wh kg−1). Introducing vacancies in CoMn 2 O 4 catalysts is regarded as an effective strategy to enhance the electrochemical performances of LOB. However, the relation between vacancy types in CoMn 2 O 4 and catalytic performances in the LOB remains ambiguous. Herein, ordered porous CoMn 2 O 4 with oxygen and metal vacancies is obtained via solvothermal reaction followed by temperature-controlled calcination using polystyrene spheres as templates. The increase in treatment temperature reduces the content of oxygen vacancies while increasing that of the metal vacancies. Notably, experimental results and theoretical calculations show that oxygen vacancies in CoMn 2 O 4 have a greater influence than metal vacancies in modulating the LiO 2 adsorption during the reaction processes and reducing the overpotential. CoMn 2 O 4 synthesized at 500 ℃ (CoMnO-500) with higher oxygen vacancies exhibits stronger adsorption onto the LiO 2 , facilitating the formation of film-like Li 2 O 2. Therefore, an LOB with the CoMnO-500 catalyst presents the lowest overpotential of 1.2 V and longest cycle lifespan of 286 cycles at a current density of 200 mA g−1. This study offers insights into the effect of CoMn 2 O 4 vacancies on the formation pathway of Li 2 O 2 discharge products. [ABSTRACT FROM AUTHOR]

[Display omitted] The design and development of high-performance and long-life Pt-free catalysts for the oxygen reduction reaction (ORR) is of great important with respect to metal-air batteries and fuel cells. Herein, a new low-cost covalent organic frameworks (COFs)-derived Co N C single-atoms catalyst (SAC) is fabricated and compared with the engineered nanoparticle (NP) counterpart for ORR activity. The ORR performance of the SAC catalyst (Co SA @NC) surpasses the NP counterpart (Co NP -NC) under the same operation condition. Co SA @NC also achieves improved long-term durability and better methanol tolerance compared with the Pt/C. The zinc-air battery assembled by the Co SA @NC cathode delivers a higher power density and energy density than that of commercial Pt/C catalyst. Molecular dynamics (MD) is performed to explain the spontaneous evolution from clusters to single-atom metal configuration and density functional theory (DFT) calculations find that Co SA @NC possesses lower d -band center, resulting in weaker interaction between the surface and the O-containing intermediates. Consequently, the reductive desorption of OH*, the rate-determine step, is further accelerated. [ABSTRACT FROM AUTHOR]

ABSTRACT One‐pot synthesis of acetamides, benzimidazoles, and benzothiazoles are central reactions for synthesizing pharmaceuticals and fine chemicals. Despite tremendous progress in heterogeneous catalysis, the synthesis of these nitrogen‐containing compounds still remains challenging. Here, we report an efficient, simple, and cost‐effective nitrogen‐doped CeO2‐supported Co single‐atom catalyst (SAC) (Co/N‐CeO2) enabled synthesis of acetamides, benzimidazoles, and benzothiazoles. As far as we know, this is the first to report that SACs catalyze the synthesis of acetamides, benzimidazoles, and benzothiazoles. Detailed spectroscopic characterization revealed the structure of catalytic center. Harnessing the catalytic activity of SACs, the work offers promising routes for future synthesis of heterocycles. [ABSTRACT FROM AUTHOR]

This research examines how varying cobalt particle sizes and support pore sizes affect CO diffusion in Fischer-Tropsch synthesis (FTS). It explores cobalt catalysts deposited on perlite (P) and its modified version (S) with weight loadings ranging from 5% to 20%. N 2 adsorption-desorption, BET analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H 2 -TPR), hydrogen temperature-programmed desorption (H 2 -TPD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR) analyses were utilized for characterization. The results designate that higher cobalt loading on the modified support (S) decreases CH 4 selectivity while enhancing selectivity towards C 5+ hydrocarbons. Despite larger cobalt particles in 15CP compared to 15CS, 15CP exhibits higher CH 4 selectivity and reduced C 5+ selectivity because of CO diffusion limitations and smaller pore size. DFT calculations reveal product selectivity depends on FTS mechanism and cobalt cluster size influences reaction pathways, with smaller clusters favoring CO insertion and larger clusters favoring carbide mechanisms. [Display omitted] • Perlite is a novel support for cobalt-based catalysts in FTS. • As the cobalt particle size increases, the methane selectivity decreases. • The cluster size influences the Fischer-Tropsch synthesis mechanism. • Both CO insertion and carbide mechanisms co-occur on large cobalt clusters. • On small cobalt clusters, only one mechanism takes place. [ABSTRACT FROM AUTHOR]

Thermo‐catalytic co‐pyrolysis of paulownia wood and polypropylene mixture were carried out in a fixed bed horizontal reactor system. The biochar obtained from pyrolysis of paulownia wood was activated by steam at 700°C. Activated biochar supported magnesium oxide, nickel oxide and cobalt oxide catalysts were prepared by incipient miosture impregnation and were used to upgrade the bio‐oil. Catalytic pyrolysis reduced the amount of bio‐oil compared with non‐catalytic pyrolysis (59.5% of bio‐oil). The results indicate that the production of aromatic compounds increased from 40.35% to 65.93, 62.12 and 61.56% using Ni, Co and Mg catalysts, respectively. For all three catalysts, the production of furan compounds decreased. It was found that bio‐char based catalysts are suitable for use in the co‐pyrolysis process to improvement the biofuel production. [ABSTRACT FROM AUTHOR]

With the ever‐growing global demand for sustainable energy solutions, hydrogen has garnered significant attention as a clean, efficient, and renewable energy source. In the field of hydrogen production, catalyst research stands out as one of the foremost areas of focus. In recent years, the preparation of electrocatalysts using ionic liquids (ILs) and deep eutectic solvents (DESs) has attracted widespread attention. ILs and DESs possess unique physicochemical properties and are recognized as green media as well as functional materials. Cobalt‐based catalysts have proven to be efficient electrocatalysts for water splitting. Incorporating ILs or DESs into the preparation of cobalt‐based catalysts offers a remarkable advantage by allowing precise control over their structural design and composition. This control directly influences the adsorption properties of the catalyst's surface and the stability of reaction intermediates, thereby enabling enhanced control over reaction pathways and product selectivity. Consequently, the catalytic activity and stability of cobalt‐based catalysts can be effectively improved. In the process of preparing cobalt‐based catalysts, ILs and DESs can serve as solvents and templates. Owing to the good solubility of ILs and DESs, they can efficiently dissolve raw materials and provide a special nucleation and growth environment, obtaining catalysts with novel‐structures. The main focus of this review is to provide a detailed introduction to metal cobalt and its oxide/hydroxide derivatives in the field of water splitting, with a particular emphasis on the research progress achieved through the utilization of IL and DES. The aim is to assist readers in designing and synthesizing novel and high‐performance electrochemical catalysts. [ABSTRACT FROM AUTHOR]

Cobalt catalysts have recently gained considerable attention as alternatives to catalysts based on precious transition metals such as Rh and Ir. Recently, Co/photoredox cooperative catalysis has emerged as a powerful tool that enables versatile transformations, including cycloaddition reactions of unsaturated compounds. In particular, 1,6‐diyne derivatives are fascinating substrates for these reactions because the corresponding exocyclic 1,3‐diene products can be further transformed into sp3‐rich carbocycles and heterocycles via functionalization of the diene moiety. The dual catalytic system can facilitate not only the cycloaddition based on the activation of the π‐bond only, such as alkyne cyclotrimerization, but also the cycloaddition involving σ‐bond activation. This Concept highlights the recent advances in Co/photoredox cooperative‐catalysis‐enabled cycloaddition reactions, focusing on the reactions of 1,6‐diyne substrates, which are difficult to perform when well‐defined cationic CoI catalysis is employed. [ABSTRACT FROM AUTHOR]

Herein, it is demonstrated that a chemical waste from the silicon industry, namely polymethylhydrosiloxane (PMHS), is a suitable hydrosilane source for the challenging, selective aerobic oxidation of olefins into methyl ketones under cobalt catalysis: a first row, abundant in the Earth's crust and cheap metal with low toxicity. The catalytic system operates under unprecedented, stoichiometric amounts of hydrosilane while the cobalt catalyst loading is kept at a very low 1 mol% with the reactions being finished in less than 1 hour with very high turnover numbers (1,340) and record‐breaking turnover frequency values up to 530 h−1. Mechanistic studies highlight the key role of the porphyrin ligand for stabilizing the active cobalt species that does follow a radical‐based reaction pathway under these particular conditions. These results are relevant for replacing the expensive and scarce palladium catalyst, traditionally used for Wacker‐type oxidations, by first‐row, Earth‐abundant transition metals under green conditions including the efficient valorization of a chemical waste such as PMHS. [ABSTRACT FROM AUTHOR]

The reduction of dioxygen to produce selectively H2O2 or H2O is crucial in various fields. While platinum‐based materials excel in 4H+/4e− oxygen reduction reaction (ORR) catalysis, cost and resource limitations drive the search for cost‐effective and abundant transition metal catalysts. It is thus of great importance to understand how the selectivity and efficiency of 3d‐metal ORR catalysts can be tuned. In this context, we report on a Co complex supported by a bisthiolate N2S2‐donor ligand acting as a homogeneous ORR catalyst in acetonitrile solutions both in the presence of a one‐electron reducing agent (selectivity for H2O of 93 % and TOFi=3 000 h−1) and under electrochemically‐assisted conditions (0.81 V <η<1.10 V, selectivity for H2O between 85 % and 95 %). Interestingly, such a predominant 4H+/4e− pathway for Co‐based ORR catalysts is rare, highlighting the key role of the thiolate donor ligand. Besides, the selectivity of this Co catalyst under chemical ORR conditions is inverse with respect to the Mn and Fe catalysts supported by the same ligand, which evidences the impact of the nature of the metal ion on the ORR selectivity. [ABSTRACT FROM AUTHOR]

The rising demand and financial costs of noble transition metal catalysts have emphasized the need for sustainable catalytic approaches. Over the past few years, base‐metal catalysts have emerged as ideal candidates to replace their noble‐metal counterparts because of their abundance and easiness of handling. Despite the significant advancements achieved with precious transition metals, earth‐abundant cobalt catalysts have emerged as efficient alternatives for allylic substitution reactions. In this review, allylic alkylations at sp3‐carbon centers mediated by cobalt will be discussed, with a special focus on the mechanistic features, scope, and limitations. [ABSTRACT FROM AUTHOR]

Aliovalent substitution reduces the oxygen vacancy formation energy and generates more oxygen vacancies to facilitate the catalytic reaction. [Display omitted] Developing cost-effective monolith catalyst with superior low-temperature activity is critical for oxidative efficacious removal of industrial volatile organic compounds (VOCs). However, the complexity of the industrial flue gas conditions demands the need for high moisture tolerance, which is challenging. Herein, CoMn–Metal Organic Framework (CoMn–MOF) was in situ grown on Ni foam (NiF) at room temperature to synthesize the cost-effective monolith catalyst. The optimized catalyst, Co1Mn1/NiF, exhibited excellent performance in toluene oxidation (T 90 = 239 °C) due to the substitution of manganese into the cobalt lattice. This substitution weakened the Co–O bond strength, creating more oxygen vacancies and increasing the active oxygen species content. Additionally, experimentally and computationally evidence revealed that the mutual inhibiting effect of three typical aromatic hydrocarbons (benzene, toluene and m–xylene) over the Co1Mn1/NiF catalyst was attributed to the competitive adsorption occurring on the active site. Furthermore, the Co1Mn1/NiF catalyst also presents outstanding water resistance, particularly at a concentration of 3 vol%, where the activity is even enhanced. This was attributed to the lower water adsorption and dissociation energy derived from the interaction between the bimetals. Results demonstrate that the dissociation of water vapor enables more reactive oxygen species to participate in the reaction which reduces the formation of intermediates and facilitates the reaction. This investigation provides new insights into the preparation of oxygen vacancy–rich monolith catalysts with high water resistance for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] In the present study, the catalyst modified with alkaline oxide can enhance the selectivity to primary amines. However, the addition of alkaline oxide inevitably reduces catalytic activity. In this study, NiCo-NC@BaO-MFC catalyst derived from zeolitic imidazolate framework-67, Ba(CH 3 COO) 2 , and melamine formaldehyde (MF) resin was prepared and used for the hydrogenation of adiponitrile (ADN) to hexamethylene diamine (HDMA). The carbon layer obtained from the MF resin effectively prevents the interaction between barium (Ba) and the active center, thus improving target product selectivity without decreasing catalytic activity. The results of the density functional theory (DFT) calculation and characterization indicated that the effect of synergy between nickel (Ni) and cobalt (Co) bimetals induces an electron density growth on the Ni surface, bringing the d-band center toward the Fermi surface. Meanwhile, the high electron density of the active center compensates for the electron-deficient state of the carbon atom in –C N, thus improving the catalytic activity. Furthermore, it was found that the introduction of Ba promotes the formation of nucleophilic hydrogen anions, which facilitates the hydrogenation of 6-aminohexylimine (AHIM) to HDMA and inhibits the intramolecular condensation of AHIM, hence improving the selectivity to HDMA. The NiCo-NC@BaO-MFC catalyst gives 98.6 % ADN conversion and 97.2 % selectivity to HDMA in an alkali-free system. [ABSTRACT FROM AUTHOR]

The selective conversion of unsaturated compounds has emerged as a crucial method in chemical synthesis, enabling the synthesis of functional organic molecules. In recent decades, transition metal‐catalyzed hydrosilylation has emerged as a highly successful exemplar of industrialization within the realm of organic chemistry for the production of organosilanes, which have a pivotal role in organic chemistry and materials science. Precious metal complexes are typically employed as catalysts in most industrial hydrosilylation processes. The exploration of Earth‐abundant alternatives has emerged as a focal point of considerable research attention due to the high cost, poor selectivity, and many side reactions reported for precious metal catalysts. Ligand skeleton construction, selectivity, and mechanism research are areas where cobalt catalysts have more potential than iron and nickel. This review discusses the recent advances in cobalt‐catalyzed hydrosilylation across carbon‐carbon, carbon‐oxygen, and carbon‐nitrogen multiple bonds from 2019 to 2023. [ABSTRACT FROM AUTHOR]

Sustainable alternatives for the energy intensive synthesis of H2O2 are necessary. Molecular cobalt catalysts show potential but are typically restricted by undesired bimolecular pathways leading to the breakdown of both H2O2 and the catalyst. The confinement of cobalt porphyrins in the PCN‐224 metal‐organic framework leads to an enhanced selectivity towards H2O2 and stability of the catalyst. Consequently, oxygen can now be selectively reduced to hydrogen peroxide with a stable conversion for at least 5 h, illustrating the potential of catalysts confined in MOFs to increase the selectivity and stability of electrocatalytic conversions. [ABSTRACT FROM AUTHOR]

Studying the interactions between CO2 sorbents and electrocatalysts for the electrochemical CO2 reduction reaction (e-CO2RR) can offer viable strategies to advance the development of the Reactive Capture of CO2 (RCC). In this report we studied the effect of amines on the performance of the [Co(PDI-Py)] catalyst for the e-CO2RR. The presence of amines shifts the onset potential for the e-CO2RR more positive and increases the catalytic activity while maintaining the high Faradaic efficiency (≥90%) for CO production. [ABSTRACT FROM AUTHOR]

In this study, Co3O4 nanoparticles were used as nanocatalyst for two different series of nitrogen-containing heterocyclic compounds, including pyrrole (Pyo) derivatives and pyrano [2, 3-c]pyrazole (Pya[2, 3-c]Pyz) derivatives. In the synthesis of derivatives, using 15 mol% and 10 mol% of the catalyst for Pyo derivatives and Pya[2, 3-c]Pyz derivatives, respectively, an efficiency between 83% and 96%, were observed. In addition, novel derivatives of Pyo and Pya[2,3- c]Pyz were synthesized and their structures were confirmed. In general, the advantages of using cobalt nanoparticles compared to previous reports include the synthesis of new derivatives, lower temperature used in the synthesis of derivatives, shorter synthesis time and high efficiency. The biological properties of the synthesized products, such as antibacterial, antifungal, and antioxidant properties, were tested and investigated. In antibacterial and antifungal tests, IZD, MIC, MBC, and MFC were measured and reported. In antioxidant activity, IC50 was calculated and reported. High reusability, green and environmentally friendly, synthesis of new derivatives and synthesis of products with higher efficiency and shorter time were the important benefits of using cobalt nanoparticles as a catalyst. In antioxidant tests, the IC50 for synthesized Pyo derivatives and Pya[2, 3-c] Pyz derivatives were between 12.2 and 13.71 μg/mL, and 16.18--17.75 μg/mL, respectively. In antimicrobial testes, the MIC for synthesized Pyo derivatives and Pya[2, 3-c]Pyz derivatives were between 2 and 4,096 μg/mL, and 2--2048 μg/mL, respectively. The results showed that the antioxidant property of Pyo derivatives were more than Pya[2, 3-c] Pyz derivatives, but the antimicrobial effect of Pya[2,3-c] Pyz derivatives were more than Pyo derivatives. The antioxidant results proved that the activity of Pyo derivatives and Pya[2, 3-c] Pyz derivatives does not depend on the substitutions of the derivatives and is close to each other. Therefore, based on this, a proposed mechanism for stability of DPPH by Pyo derivatives and Pya[2, 3-c] Pyz derivatives were suggested. Finally, based on the more stable resonance structures of Pyo derivatives, compared to Pya[2, 3-c] Pyz derivatives, its high antioxidant property was justified. Pya[2, 3-c] Pyz derivatives has two heterocyclic rings connected together pyrano and pyrazole, but Pyo derivatives has only one heterocyclic ring (pyrrole). So high antimicrobial property of Pya[2, 3-c] Pyz derivatives compared to Pyo derivatives can be attributed to having two bioactive heterocyclic rings. [ABSTRACT FROM AUTHOR]

This document is a contents list for the New Journal of Chemistry, a publication by The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. It includes titles and authors of various articles covering topics such as hydrogenation products of fatty acids, macrocycles obtained from condensation reactions, and the characteristics of copper(II) Schiff base complexes as antimicrobial agents. Other papers mentioned in the document discuss catalytic hydrogenation, drug encapsulation, and the removal of pollutants from water. The document includes three papers and a correction, covering topics such as the synthesis of diaminoacetylene, the Z-scheme of 2D structured BCN and Ti MOF heterojunctions for photocatalytic hydrogen evolution, and the crafting of flexible film photocatalysts for formic acid production from CO2 and cyclization of thioamides. [Extracted from the article]

Co3O4 was prepared as a precursor for Co catalysts for hydrodeoxygenation of n-octanoic acid, with four precipitants applied to modulate the surface acidity distribution. It was observed that medium acidity facilitated esterification, medium–strong acidity promoted partial hydrogenation to alcohols, and strong acidity produced alkanes with one carbon loss. [ABSTRACT FROM AUTHOR]

Cobalt carbides have been recognized as an active phase for the production of light olefins and alcohols in Fischer–Tropsch synthesis. In this study, in situ X-ray diffraction experiments were performed to investigate the stability and catalytic performance over a single-phase Co3C catalyst under reaction conditions. The in situ X-ray diffraction results indicated that the Co3C phase remained stable with no significant changes until the temperature reached 300 °C. The high stability can be attributed to the twinning structure of the single-phase Co3C catalyst. The catalytic evaluation results showed that the single-phase Co3C catalyst had higher activity with high selectivity to long-chain products due to the unique surface structure of Co3C. This work provides guidance for the rational design of efficient cobalt carbide catalysts for Fischer–Tropsch synthesis reactions. [ABSTRACT FROM AUTHOR]

Developing high‐performance, high‐stability, and low‐cost nonprecious metal catalysts to enhance the performance of zinc–air batteries (ZABs) holds significant importance. A bifunctional catalyst consisting of cobalt oxide (CoO) nanocrystals on nitrogen‐doped reduced graphene oxide nanoribbons (N‐rGONR) as a novel substrate is successfully synthesized in this work. This synthesized bifunctional catalyst exhibits mesoporous structure, and remarkable synergistic effects between CoO nanocrystals and N‐rGONR, demonstrating excellent activity and durability in both oxygen reduction reactions and oxygen evolution reactions. Notably, the resulting aqueous electrolyte ZABs show a high discharge peak power density of 196 mW cm−2, a high specific capacity of 615.9 mAh g−1, and long‐time stability for 648 h. Furthermore, the assembly of 1D and 2D flexible solid‐state ZABs fabricated using this bifunctional catalyst exhibits stable electrochemical performance, even under severe deformation. These results underscore the considerable promise of implementing the CoO@N‐rGONR catalyst structure in next‐generation advanced energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

In the quest for sustainable lignin valorization, the development of efficient catalytic systems for hydrogenolysis of lignin-derived compounds remains a pivotal focus. Utilizing sub-nanometer cobalt catalysts, we achieved the successful hydrogenolysis of model lignin molecules, including 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)ethanone and 2-(2,6-dimethylphenoxy)-1-(3,4-dimethoxyphenyl), resulting in the formation of highly efficient catalytic species characterized by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Our catalyst exhibited remarkable recyclability over five cycles. Additionally, we conducted hydrogenolysis tests on authentic lignin samples, shedding light on the promising potential of this approach for sustainable lignin valorization. [ABSTRACT FROM AUTHOR]

Single-crystal-to-single-crystal (SCSC) transformations provide more avenues for phase transitions, which have piqued great interest in crystal engineering. In this work, a 3D Co(II)-based coordination polymer (CP), {Co2(OH2)8(btec)}·4H2O (1), (where (btec)4− = 1,2,4,5-benzenetetracarboxylate) undergoes SCSC transition upon heating at 180 °C to afford an anhydrous phase [Co2(btec)] (1′). Room-temperature water-vapour induced semi-reversible SCSC transformation of 1′ involves condensation of two water molecules coordinating to the metal cluster, yielding a new framework [Co2(OH2)2(btec)] (2). These SCSC transitions were accomplished through a sequential bond breaking and new bond formation process which was accompanied by colour changes from orange (1) → violet (1′) → pink (2). All materials were structurally elucidated by single-crystal X-ray diffraction (SCXRD) and further established by various analytical techniques. According to SCXRD data, all the frameworks possess octahedral geometries around the cobalt(II) sphere. SCXRD studies further revealed that 1 is a polymeric architecture with a binodal 4-c sql topology while 1′ and 2 possess (3,6)-c kgd and (4,6)-c scu 3D nets, respectively. By virtue of multitopicity exhibited by the tetracarboxylate, the coordination number of the linker around the Co(II) sphere increased from four (in 1) to eight (in 1′) and then decreased to six (in 2). Most interestingly, permanent porosity could be observed for the dihydrate 2, originated from potential void space as substantiated by dinitrogen (N2) sorption isotherm. These porous frameworks were active catalysts for the aerobic epoxidation of the model substrate cyclohexene using molecular oxygen (O2) as the final oxidant in the presence of the sacrificial i-butyraldehyde (IBA) reductant. For using the dihydrous phase 2, cyclohexene and various other olefins were catalytically oxidised to their corresponding epoxides with up to 38.5% conversion and 99.0% selectivity. The catalyst 2 can be expediently recycled in four runs without significant loss of activity. This research demonstrates that a little innovation in the active-site-engineered organic–inorganic hybrid materials can significantly enhance the catalytic performance and selectivity of coordination polymer-derived heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Herein we report the catalytic ethanol decomposition over cobalt catalyst synthesized using conventional solution combustion synthesis (SCS). The reaction pathway proposed in-situ DRIFT analysis shows that the decomposition reaction proceeds through the formation of surface ethoxy intermediates that transformed into acetates and aldehydes which further decompose to releases CH 4 , H 2 and CO 2 with some deposition of carbon on the catalyst surface. The catalytic reaction shows 100 % ethanol conversion at 420 °C, with high selectivity of H 2 in the output. The structural transformation of the catalyst and deposited carbon was analyzed using high-resolution transmission electron microscope (HRTEM). Presence of small Co nanoparticles (size <30 nm) surrounded with graphene and larger metal nanoparticles trapped inside MWCNTs was visible during a stability run over 50 h that motivates in proposing the reaction mechanism of the fluctuating metal nanoparticle along with carbon on the catalyst surface. Moreover, this work opens up the possibility of synthesizing highly dispersed Co nanoparticles in an efficient way without any complex experimental procedures and equipment that can further be used as effective catalysts in many industrial reactions. • Catalytic reaction shows 100 % ethanol conversion at 420 °C on cobalt catalyst. • Transformation on particle and carbon structure during stability run is seen. • Co nanoparticles between 10 and 30 nm with graphene layer were observed. • Metal nanoparticles trapped inside MWCNTs after 50 h of ethanol conversion. • Proposed mechanism describes the metal nanoparticle fluctuation with carbon structure. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of carbon dioxide (CO2) or carbon monoxide (CO) to valuable multi-carbon (C2+) products like acetate is a promising approach for a sustainable energy economy. However, it is still challenging to achieve high activity and selectivity for acetate production, especially in neutral electrolytes. Herein, a bioinspired hemin/Cu hybrid catalyst was developed to enhance the surface *CO coverage for highly efficient electroreduction of CO to acetate fuels. The hemin/Cu electrocatalyst exhibits a remarkable faradaic efficiency of 45.2% for CO-to-acetate electroreduction and a high acetate partial current density of 152.3 mA cm−2. Furthermore, the developed hybrid catalyst can operate stably at 200 mA cm−2 for 14.6 hours, producing concentrated acetate aqueous solutions (0.235 M, 2.1 wt%). The results of in situ Raman spectroscopy and theoretical calculations proved that the Fe–N4 structure of hemin could enhance the CO adsorption and enrich the local concentration of CO, thereby improving C–C coupling for acetate production. In addition, compared to the unmodified Cu catalysts, the Cu catalysts functionalized with cobalt phthalocyanine with a Co–N4 structure also exhibit improved acetate performance, proving the universality of this bioinspired molecule-enhanced strategy. This work paves a new way to designing bioinspired electrolysis systems for producing specific C2+ products from CO2 or CO electroreduction. [ABSTRACT FROM AUTHOR]

NaBH4 is an attractive candidate for closed-loop hydrogen generation in small practical applications owing to its ambient condition hydrogen release mechanism, non-toxic byproduct, ability to regenerate, and stability at ambient conditions. The hydrolysis of NaBH4 requires a catalyst to accelerate the hydrogen generation process and cobalt oxide is one such promising catalyst in this reaction. The surface species and crystalline phases of cobalt oxide catalysts play an important role in determining the hydrogen generation rate and overall hydrolysis process. In this study, cobalt oxide nanoparticles are synthesized by a thermal plasma route. The two crystalline phases, namely c-CoO and Co3O4, are tuned using thermal plasma operating conditions. The catalysts so obtained have been thoroughly characterized using analytical techniques like XRD, XPS, HR-TEM, etc. Furthermore, the catalyst was used for hydrogen production in the hydrolysis process of NaBH4. The ex situ X-ray photoelectron spectra recorded at different stages of the hydrolysis process have been extensively used to understand surface modifications occurring at the surface of the catalyst. The Co+3/Co+2 ratio and attachment of other species during hydrolysis analyzed using XPS are correlated with the overall hydrolysis reaction before and after catalysis. It was concluded that the presence of the c-CoO (i.e. initial Co+2 species presence) phase brings stability to hydrogen production in that cycle. [ABSTRACT FROM AUTHOR]

NaBH4 is an attractive candidate for closed-loop hydrogen generation in small practical applications owing to its ambient condition hydrogen release mechanism, non-toxic byproduct, ability to regenerate, and stability at ambient conditions. The hydrolysis of NaBH4 requires a catalyst to accelerate the hydrogen generation process and cobalt oxide is one such promising catalyst in this reaction. The surface species and crystalline phases of cobalt oxide catalysts play an important role in determining the hydrogen generation rate and overall hydrolysis process. In this study, cobalt oxide nanoparticles are synthesized by a thermal plasma route. The two crystalline phases, namely c-CoO and Co3O4, are tuned using thermal plasma operating conditions. The catalysts so obtained have been thoroughly characterized using analytical techniques like XRD, XPS, HR-TEM, etc. Furthermore, the catalyst was used for hydrogen production in the hydrolysis process of NaBH4. The ex situ X-ray photoelectron spectra recorded at different stages of the hydrolysis process have been extensively used to understand surface modifications occurring at the surface of the catalyst. The Co+3/Co+2 ratio and attachment of other species during hydrolysis analyzed using XPS are correlated with the overall hydrolysis reaction before and after catalysis. It was concluded that the presence of the c-CoO (i.e. initial Co+2 species presence) phase brings stability to hydrogen production in that cycle. [ABSTRACT FROM AUTHOR]

Porphyrin‐based metal‐organic frameworks (MOFs) have received great attention for solar photochemistry applications. Manipulating the direction of energy (exciton) migration plays an essential role in boosting the light‐harvesting efficiency of porphyrin‐based MOFs. Here, based on the time‐dependent exciton‐exciton annihilation rate, an optical control of directional exciton migration is demonstrated in cobalt‐porphyrin surface‐supported MOF nanofilms (Co‐TCPP SURMOFs). Utilizing photocarrier densities or lattice temperature as the control knob, the dynamic form of exciton migration in Co‐TCPP SURMOFs can be switched between the nearest‐neighbor 1D interaction and the quasi‐isotropic 2D interaction, which is well explained using a diffusion model of exciton‐exciton scattering. This results provide an optical approach to regulating exciton migration in MOFs, which enhances understanding of the excitonic behavior in artificial light harvesters. [ABSTRACT FROM AUTHOR]

Cobalt single atom catalysts (SACs) have exhibited promising performance in both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), positioning them as potential dual‐functional catalysts for Zn‐air battery. However, the long‐standing challenge lies in achieving satisfactory dual‐functionality and stability of these SACs. In this study, to optimize the 4e‒ ORR performance, boron (B) atoms are employed with low electronegativity to regulate the structure of the Co–N–C catalytic center. This resulted in the formation of an asymmetrically coordinated Co metal center catalyst (Co‐N3B). Compared to the Co‐N4, Co‐N3B exhibited lower free energy for ORR and stronger adsorption energy toward *O species, effectively suppressing the 2e‒ ORR pathway at the cobalt site and preventing catalyst corrosion induced by hydrogen peroxide (H2O2) in ORR reactions, thereby enhancing catalyst stability. In situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) further validated excellent interaction between Co active centers and O intermediates. Furthermore, the self‐made rechargeable zinc‐air battery demonstrated remarkable discharge peak power density (≈253 mW cm‒2), energy density (≈819 mAh g‒1), and cyclic stability exceeding 110 h. This study provides new insights into constructing catalysts with atomic‐level precision and offers strong references for practical applications in energy storage and convension electrocatalysts. [ABSTRACT FROM AUTHOR]

In this study, the applicability of a Co2+-doped catalyst [(Co-Ver) cat ] fabricated from clay vermiculite ore for the synthesis of hydrogen from sodium borohydride was investigated. FT-IR, XRD, SEM, Brunauer-Emmett-Teller (BET) analysis, and X-ray fluorescence (XRF) studies were used to characterize the synthesized (Co-Ver) cat. After activation with 1 M HCl, 0.15 g the 30% Co2+-doped catalyst (7% NaOH, 2.5% NaBH 4 , 30 °C process temperature) produced the maximum catalytic activity. Under these conditions, the hydrogen generation rate of 1991,39 ml g Co −1 min−1was achieved with the (Co-Ver) cat. The NaBH 4 hydrolysis reaction had an activation energy of 43.58 kJ mol−1 and a reaction rate order (n) of 0.18. It was also determined that the prepared (Co-Ver) cat exhibited good reusability. The reusability of the (Co-Ver) cat prepared from vermiculite ore was high, and 91.78% of the expected hydrogen amount was obtained as a result of its 10th use. • A cobalt doped catalyst was prepared from raw vermiculite ore for NaBH 4 hydrolysis. • The hydrogen generation rate was calculated as 1991.39 ml g Co −1 min−1 at 30 °C. • The activation energy for NaBH 4 hydrolysis was founded 43.58 kJ mol−1 [ABSTRACT FROM AUTHOR]

To address the substantial energy needs of the quickly evolving modern civilization, efforts are still needed to provide sustainable renewable energy sources. The electrocatalytic Oxygen evolution reaction (OER) is one of the essential technologies used in the various hydrogen production techniques. ZIF‐67 nanocubes (ZIF‐67 NCs) were synthesized in an aqueous solution and used as sacrificial templates. Cobalt nitrate hexahydrate was added under water bath conditions, resulting in the evolution of numerous small layered layers of cobalt hydroxide. This ultimately led to the formation of multilayered, three‐dimensionally crosslinked Co‐LDH with a porous networked cubic morphology. Hydrolysis of Co2+ at different concentrations produces different degrees of weak acidic environments, and the loose LDH on the cubic structure of the best catalyst, Co‐LDH‐1, exposes more active cobalt sites for the OER, which results in a high electrochemically active surface area, with an overpotential of 354 mV and a Tafel slope of 79.06 mV dec−1 at a current density of 10 mA cm−2, and good stability and low activation under alkaline condition also has good stability and low activation energy. It provides us an easy and practical plan for logically creating ZIF‐derived hydroxide materials, leading to the development of affordable and effective electrocatalysts. [ABSTRACT FROM AUTHOR]

The oxidative carbonylation of methanol to synthesize dimethyl carbonate (DMC) has been extensively studied over Cu‐based catalysts, but the activity and selectivity are not high. The Co catalysts exhibit high DMC selectivity, but the difficulty in recycling homogeneous Co catalyst and the low conversion of heterogeneous Co catalyst limit the application of Co catalysts. Here, the core–shell ZIFs materials were synthesized and carbonized to obtain solid core–shell cobalt catalysts, and then the catalytic performance for methanol conversion to DMC was investigated. The CoNC@NC catalyst, carbonized from Z67@Z8 with Z67 as the core and Z8 as the shell, shows that the carbonized NC shell effectively suppressed the aggregation of Co NPs and the Co NPs were only 15.4 nm, which was much smaller than those of NC@CoNC (34.5 nm) and CoNC (48.1 nm) catalysts. Compared with the CoNC catalyst, CoNC@NC significantly improved the pulse chemisorption of CH3OH and CO, leading to a significant increase in methanol conversion from 6.9% to 17.1%. Furthermore, the deactivation rate of the CoNC@NC catalyst (22.8%) was much lower than that of CoNC (59.4%) after five reaction cycles. The results of this work provide a new strategy for the design and preparation of solid cobalt catalysts for the oxidative carbonylation of methanol to DMC. [ABSTRACT FROM AUTHOR]

Co-based catalysts have shown great promise for propane dehydrogenation (PDH) reactions due to their merits of environmental friendliness and low cost. In this study, ordered mesoporous molecular sieve-supported CoOx species (CoOx/Al-SBA-15 catalyst) were prepared by one-step organometallic complexation. The catalysts show worm-like morphology with regular straight-through mesoporous pores and high external specific surface area. These typical features can substantially enhance the dispersion of CoOx species and mass transfer of reactants and products. Compared with the conventional impregnation method, the 10CSOC (10 wt.% Co/Al-SBA-15 prepared by the organometallic complexation method) sample presents a smaller CoOx size and higher Co2+/Co3+ ratio. When applied to PDH reaction, the 10CSOC delivers higher propane conversion and propylene selectivity. Under the optimal conditions (625 °C and 4500 h−1), 10CSOC achieves high propane conversion (43%) and propylene selectivity (83%). This is attributed to the smaller and better dispersion of CoOx nanoparticles, more suitable acid properties, and higher content of Co2+ species. This work paves the way for the rational design of high-performance catalysts for industrially important reactions. [ABSTRACT FROM AUTHOR]

Hydrogenation of N‐heteroarenes to saturated N‐heterocycles is an important reaction in organic synthesis. Hydrogen is a green reducing reagent and has been widely applied in industrial production. The development of an appropriate catalyst to realize hydrogenation at low pressure and temperature is desired. In this study, we developed a cobalt‐based catalyst derived from ZIF‐67 that exhibits high activity for N‐heteroarene hydrogenation under 5–20 bar hydrogen, which is a relatively low pressure as compared to reported catalytic systems. This nano‐cobalt catalyst shows broad substrate scope and can be reused without obvious activity loss. [ABSTRACT FROM AUTHOR]

Direct conversion of carbon monoxide into fuel through Fischer–Tropsch synthesis (FTS) is economically and environmentally beneficial as an alternative clean energy source. However, the activity and product selectivity need further investigation. In this work, a Co-MOF-71 (Co(1,4-BDC) (DMF)) was prepared solvothermally and pyrolyzed under nitrogen flow at low pyrolysis temperature to obtain a highly mesoporous Co@C-500 catalyst. The obtained catalyst exhibits high cobalt loading (53 wt%), high reducibility, optimum nanoparticle size (10.49 nm), and well-dispersed active sites. The catalytic activity of the catalyst was tested under different reaction conditions using a stainless steel fixed-bed reactor. The optimal performance showed a high CO conversion (82.7%), high C5+ selectivity (82.77%) with C5–C12 gasoline range hydrocarbons (71.9%), low C2–C4 selectivity (13%), and low methane selectivity (3.7%). Furthermore, the catalyst has a high C5+ yield of 68%, with the gasoline fraction (C5–C12) being the main product (59.1% yield). The catalyst shows superior FTS performance compared with other reported Co-containing catalysts, especially after being tested for more than 120 h without deactivation. Therefore, this work could contribute to the design of high-efficiency MOF-derived Co-FTS catalysts that could be used in the production of green and sustainable transportation fuel (gasoline). [ABSTRACT FROM AUTHOR]

Hydrogen production by H2S catalytic thermal decomposition was studied using Co mesostructured catalysts, directly synthesized by the Evaporation-Induced Self-Assembly method with molar ratios Co/Si of 0.01, 0.05, and 0.10. Cobalt was incorporated into the tetracoordinate silica structure, and lesser amounts of cobalt were left outside the structure in the spinel species of Co3O4. The H2S decomposition reaction was conducted at 400–800 °C under atmospheric pressure and continuous flow. The catalytic activity of catalysts was increased with the rising of temperature, reaching H2 maximum conversions at 800 °C; the conversion at this temperature for 0.01Co–SBA-15 was 28.4%, 0.05Co–SBA-15 was 29.5%, and 38.0% for 0.10Co–SBA-15. All catalysts showed high stability during the reaction without apparent deactivation, and the best activity was for 0.10Co–SBA-15, with a reaction rate of 0.63 mol h−1 g−1 and an energy activation of 51 kJ mol−1. During the reaction, cobalt oxidized phases were transformed into the sulphurated phase CoS by simultaneous reduction and sulphuration processes, which are due to the stream of H2S and the temperature. On the other hand, the sulfur formed was condensed as a yellow solid in the reactor outlet. The results showed that the experimental approach is an efficient alternative for synthesizing Co catalysts under soft conditions, with high activity and stability in H2 and sulfur production using a problematic gas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pt-NiCoMnO 4 catalysts are firstly prepared for FA oxidation in air. • 1 %Pt-NiCoMnO 4 achieves 100 % FA conversion at RT (GHSV: 5,964 h−1). • FA is converted into CO 2 with diverse forms of intermediates, e.g., DOM and HCOO–. • FA and O 2 are adsorbed preferably on the Pt and nearby Ni sites, respectively. • Platinum-nickel sites offer favorable electronic structures for FA oxidation. Formaldehyde (FA), a carcinogenic oxygenated volatile organic compound, is present ubiquitously in indoor air. As such, it is generally regarded as a critical target for air quality management. The oxidative removal of FA under dark and room-temperature (RT) conditions is of practical significance. A series of ternary nickel–cobalt-manganese oxide–supported platinum catalysts (Pt/NiCoMnO 4) have been synthesized for FA oxidative removal at RT in the dark. Their RT conversion values for 50 ppm FA (X FA) at 5,964 h−1 gas hourly space velocity (GHSV) decrease in the following order: 1 wt% Pt/NiCoMnO 4 (100 %) > 0.5 wt% Pt/NiCoMnO 4 (25 %) > 0.05 wt% Pt/NiCoMnO 4 (14 %) > NiCoMnO 4 (6 %). The catalytic performance of 1 wt% Pt/NiCoMnO 4 has been examined further under the control of various process variables (e.g., catalyst mass, flow rate, relative humidity, FA concentration, time on stream, and molecular oxygen content). The catalytic oxidation of FA at low temperatures (e.g., RT and 60 °C) is accounted for by Langmuir–Hinshelwood mechanism (single-site competitive-adsorption), while Mars van Krevelen kinetics is prevalent at higher temperatures. In situ diffuse-reflectance infrared Fourier-transform spectroscopy reveals that FA oxidation proceeds through a series of reaction intermediates such as DOM, HCOO–, and CO 3 2–. Based on the density functional theory simulations, the unique electronic structures of the nearest surface atoms (platinum and nickel) are suggested to be responsible for the superior catalytic activity of Pt/NiCoMnO 4. [ABSTRACT FROM AUTHOR]

[Display omitted] The optimization of the adsorption of oxygen-containing intermediates on platinum (Pt) sites of Pt-based electrocatalysts is crucial for the oxygen reduction reaction process. Currently, a large amount of researches mainly focus on modifying the bulk structure of the electrocatalysts, however, the vital role of solvent effect on the phase interfaces is often overlooked. Here, we successfully developed an electrocatalyst in which the ordered PtCo alloy anchors on the cobalt (Co) single-atoms/clusters decorated support (Co 1,n N C) and its surface is further optimized using hydrophobic ionic liquid (IL). Experimental studies and theoretical calculations indicate that compressive stress on Pt lattice contributed by intrinsic structure and the local hydrophobicity caused by IL on the surface can suppress the stabilization of *OH on Pt. This synergistic effect affords outstanding catalytic performance, exhibiting a half-wave potential (E 1/2) of 0.916 V vs. RHE and a mass activity (MA) of 1350.3 mA mg Pt −1 in 0.1 mol/L perchloric acid (0.1 M HClO 4) electrolyte, much better than the commercial Pt/C (0.849 V vs. RHE and 145.5 mA mg Pt −1 for E 1/2 and MA, respectively). Moreover, the E 1/2 of IL-PtCo/Co 1,n N C only lost 5 mV after 10,000 cyclic voltammetry (CV) cycles due to a strong and synergistic contact of the intermetallic PtCo alloy with the Co 1,n N C support and IL. This research provides an effective method for designing efficient electrocatalysts by combining intrinsic structure and surface modification. [ABSTRACT FROM AUTHOR]

L-Cysteine is a semi-essential and proteinogenic amino acid, with the formula HO2CCH (NH2) CH2SH. L-cysteine is mostly found in protein-rich foods. In this study, catalysts consisting of cobalt (Co) supported on carbon nanotubes (CNTs) were prepared using the sodium borohydride (NaBH4) reduction method. These catalysts were characterized by means of energy-dispersive x-ray (EDX) with scanning electron microscopy (SEM), temperature-programmed reduction (TPR), and temperature-programmed oxidation (TPO) techniques. Characterization results confirmed the successful preparation of the desired catalyst. After preparing the Co/CNT catalysts, a highly efficient and sensitive electrochemical sensor was developed using a glassy carbon electrode (GCE) modified with the Co/CNT catalysts. The electrochemical behavior of the bare GCE and Co/CNT-modified GCE electrodes was investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) in 0.1 M phosphate buffer solution (PBS) + L-cysteine. Electrochemical results showed that the Co/CNT-modified GCE electrode exhibited high sensitivity and selectivity compared to the bare GCE, with sensitivity of 0.0046 µA/µM, limit of detection of 0.2 µM, and limit of quantification of 0.6 µM. Furthermore, this electrode showed higher sensitivity values than those reported in the literature. Further interference studies were performed using CV and EIS to investigate interfering species in the serum environment, such as D-glucose, uric acid, L-tyrosine, and L-tryptophan. In conclusion, the results suggest that the Co/CNT-modified GCE electrode is a promising catalyst for the sensitive detection of L-cysteine. [ABSTRACT FROM AUTHOR]

A Zn-air battery-driven SOR||HER coupling system based on a trifunctional P-CoMoO 4 /NF catalyst has been developed for self-powered synchronous sulfur recovery and hydrogen production. [Display omitted] • The self-driven SOR/HER hybrid electrolysis system was assembled for the first time. • P-CoMoO 4 /NF electrocatalysts were designed as three-dimensional catalyst for HER, SOR and ORR. • The sulfur-containing waste water can be recycled and H 2 generation occurs spontaneously. • The electrolysis can be realized without external energy consumption. This study introduces a self-driven system that effectively achieves synchronized sulfur recovery and hydrogen production using a Zn-air battery. The system ingeniously integrates the sulfur oxidation reaction (SOR) and the hydrogen evolution reaction (HER) into a single, efficient process. Central to this system is the trifunctional phosphorus-doped cobalt molybdate catalyst (P-CoMoO 4 /NF), which exhibits superior performance in both HER (η j = 100 = 0.13 V) and SOR (η j = 100 = 0.30 V) with remarkable stability (∼360 h), reaching 0.64 V at 100 mA cm−2 for simultaneous sulfur ion degradation and hydrogen production. Through density functional theory simulations and extensive characterizations, it has been shown that phosphorus doping in the cobalt molybdate catalyst facilitates electron redistribution, enhancing the catalyst's conductivity, generating more oxygen vacancies, and promoting improved mass and electron transfer. This modification also lowers the energy barrier for adsorbing reaction intermediates, thus increasing the hydrogen production rate and sulfur oxide conversion in this self-powered system. In summary, this research marks a substantial advancement in the development of trifunctional catalysts and proposes an eco-friendly, cost-effective strategy for integrated reaction systems, paving the way for sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are a significant source of environmental pollution, posing threats to human safety. With growing concerns about environmental degradation, catalytic oxidation technology emerges as a paramount and widely adopted approach for VOC elimination, renowned for its operational simplicity, energy efficiency, and environmental friendliness. As a representative transition metal catalyst, cobalt‐based catalysts have garnered widespread use in VOC catalytic oxidation due to their cost‐effectiveness, versatility, and distinctive physicochemical properties. This paper provides a detailed exposition of the construction strategies and structure‐activity relationship of Co3O4‐based catalysts in VOCs oxidation reaction, encompassing both monometallic Co3O4 and multimetallic cobalt‐based catalysts. Furthermore, it offers a comprehensive summary and discussion of the latest research progress concerning Co3O4‐based catalysts in practical applications. Concluding with a meticulous analysis, the paper addresses the technical challenges inherent in developing Co3O4‐based catalysts for VOCs degradation. Additionally, it proposes research directions aimed at overcoming these challenges, contributing to the ongoing discourse on environmental sustainability. [ABSTRACT FROM AUTHOR]

The reductive catalytic fractionation (RCF) of lignocellulose, considering lignin valorization at design time, has demonstrated the entire utilization of all lignocellulose components; however, such processes always require catalysts based on precious metals or high‐loaded nonprecious metals. Herein, the study develops an ultra‐low loaded, atomically dispersed cobalt catalyst, which displays an exceptional performance in the RCF of lignocellulose. An approximately theoretical maximum yield of phenolic monomers (48.3 wt.%) from lignin is realized, rivaling precious metal catalysts. High selectivity toward 4‐propyl‐substituted guaiacol/syringol facilitates their purification and follows syntheses of highly adhesive polyesters. Lignin nanoparticles (LNPs) are generated by simple treatment of the obtained phenolic dimers and oligomers. RCF‐resulted carbohydrate pulp are more obedient to enzymatic hydrolysis. Experimental studies on lignin model compounds reveal the concerted cleavage of Cα–O and Cβ–O pathway for the rupture of β‐O‐4 structure. Overall, the approach involves valorizing products derived from lignin biopolymer, providing the opportunity for the comprehensive utilization of all components within lignocellulose. [ABSTRACT FROM AUTHOR]

The functionalization of silica supports with isonicotinamide (NIC) facilitated the stabilization of small (3.5 nm), spherical cobalt nanoparticles (CoNPs) used in catalytic hydrogenation. Various silica matrices, including amorphous, mesoporous, and non‐porous ones, were synthesized and post‐grafted with NIC to serve as ligands for stabilizing CoNPs. Comprehensive characterization techniques were employed to fully analyze the prepared materials, which were then utilized in the catalytic hydrogenation of acetophenone, serving as a benchmark reaction to assess the impact of different silica supports on catalysis. The porosity and surface nature of the silica matrices played crucial roles in anchoring the amide ligand, and the presence of the ligand was essential for stabilizing the nanoparticles. Among the catalysts tested, CoNPs@SBA‐15/NIC exhibited the highest catalytic activity and demonstrated excellent performance in the hydrogenation of alkenes, nitriles, ketones, and quinoline under relatively mild conditions. No significant alteration in catalyst morphology or leaching of metal was observed after the reaction. Notably, this catalytic system achieved turnover numbers comparable to those of homogeneous cobalt catalysts. Additionally, one‐pot tandem reductive amination reactions starting from aldehydes and involving both amines and nitrobenzene yielded secondary and tertiary amines in good yields, highlighting the robustness and versatility of the catalyst. [ABSTRACT FROM AUTHOR]

The development of efficient non-noble metal electrocatalysts for the oxygen evolution reaction (OER) under acidic conditions remains a critical challenge. Herein, we report a N-doped carbonaceous component-engineered Co3O4 (NCEC) catalyst synthesized via the sol-gel method. Dopamine hydrochloride (DA)-derived nitrogen-doped carbonaceous components were found to boost the OER performance of Co3O4. The optimized catalyst can reach an overpotential as low as 330 mV in 1 M H2SO4 at a current density of 10 mA cm-2 and maintains a good long-term stability of 60 hours. In particular, we found that the thermodynamic overpotential was inversely proportional to the content of oxidized N and pyridinic N, whereas it was directly proportional to the pyrrolic-N content. Our experiments and density functional theory (DFT) calculations confirm that the optimized catalyst exhibits enhanced charge transfer and the oxidized N species on Co3O4 is responsible for the high catalytic activity. Our study suggests that the performance of NCEC in acidic media can be further optimized by enhancing the content of oxidized N species. [ABSTRACT FROM AUTHOR]

Both, aluminum doped zinc oxide (AZO) and vertically aligned carbon nanotubes (VACNT) have outstanding properties and promising applications in the future, however, there is little information in the scientific literature on whether this is feasible. In this study, we investigated the effects of catalyst layer deposition parameters and the synthesis parameters by using a simple and cost-effective dip coating method to form alumina support layer and iron and cobalt bimetal catalyst layer on the AZO surface thereafter performing synthesis via catalytic chemical vapor deposition technique at 650 °C. In order to gain useful information about the structure of the VACNTs, several parameters were varied during both catalyst layer preparation (e.g. catalyst ink concentration) and CCVD synthesis (e.g. water vapor gas feed, the presence of hydrogen gas). The resulting samples were investigated by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results indicated that the length and structure of CNTs were strongly affected by the catalyst ink concentration and water vapor. [ABSTRACT FROM AUTHOR]

New bifunctional cobalt catalysts for combined Fischer–Tropsch synthesis and hydroprocessing of hydrocarbons containing Pt were developed. To prepare catalysts in the form of a composite mixture, the FT synthesis catalyst Co-Al2O3/SiO2 and ZSM-5 zeolite in the H-form were used as metal and acid components, respectively, with boehmite as a binder. The catalysts were characterized by various methods, such as XRD using synchrotron radiation, SEM, EDS, TEM and TPR. The effect of the Pt introduction method on the particle size and conditions for cobalt reduction was studied. The testing of catalysts in Fischer–Tropsch synthesis was carried out at a pressure of 2.0 MPa, a temperature of 240 and 250 °C, an H2/CO ratio of 2 and a synthesis gas volumetric velocity of 1000 h−1. It is shown that the method of introducing a hydrogenating metal by adjusting the nano-sized spatial structure of the catalyst determined the activity in the synthesis and group and fractional composition of the resulting products. It is established that the presence of Pt intensified the processes of synthesis and hydrogenation, including isomeric products, and reduced the content of unsaturated hydrocarbons. The application of Pt by impregnation onto the surface of the metal component of the catalysts provided the highest productivity for C5+ hydrocarbons, and for the acidic component, it enabled maximum cracking and isomerizing abilities. [ABSTRACT FROM AUTHOR]