Precisely Engineering Architectures of Co/C Sub-Microreactors for Selective Syngas Conversion

Water-participated mild oxidation of ethane to acetaldehyde

The direct conversion of low alkane such as ethane into high-value-added chemicals has remained a great challenge since the development of natural gas utilization. Herein, we achieve an efficient one-step conversion of ethane to C2 oxygenates on a Rh1/AC-SNI catalyst under a mild condition, which delivers a turnover frequency as high as 158.5 h-1. 18O isotope-GC-MS shows that the formation of ethanol and acetaldehyde follows two distinct pathways, where oxygen and water directly participate in the formation of ethanol and acetaldehyde, respectively. In situ formed intermediate species of oxygen radicals, hydroxyl radicals, vinyl groups, and ethyl groups are captured by laser desorption ionization/time of flight mass spectrometer. Density functional theory calculation shows that the activation barrier of the rate-determining step for acetaldehyde formation is much lower than that of ethanol, leading to the higher selectivity of acetaldehyde in all the products.

Precise solid-phase synthesis of CoFe@FeOx nanoparticles for efficient polysulfide regulation in lithium/sodium-sulfur batteries

Complex metal nanoparticles distributed uniformly on supports demonstrate distinctive physicochemical properties and thus attract a wide attention for applications. The commonly used wet chemistry methods display limitations to achieve the nanoparticle structure design and uniform dispersion simultaneously. Solid-phase synthesis serves as an interesting strategy which can achieve the fabrication of complex metal nanoparticles on supports. Herein, the solid-phase synthesis strategy is developed to precisely synthesize uniformly distributed CoFe@FeOx core@shell nanoparticles. Fe atoms are preferentially exsolved from CoFe alloy bulk to the surface and then be carburized into a FexC shell under thermal syngas atmosphere, subsequently the formed FexC shell is passivated by air, obtaining CoFe@FeOx with a CoFe alloy core and a FeOx shell. This strategy is universal for the synthesis of MFe@FeOx (M = Co, Ni, Mn). The CoFe@FeOx exhibits bifunctional effect on regulating polysulfides as the separator coating layer for Li-S and Na-S batteries. This method could be developed into solid-phase synthetic systems to construct well distributed complex metal nanoparticles.

Cu(BF4)2/AC-Catalyzed Synthesis of N-Substituted Anilines, N-Substituted 1,6-Naphthyridin-5(6H)-one, and Isoquinolin-1(2H)-one

Herein, we report practical Cu(BF₄)₂/activated carbon-catalyzed amination of various anilines, isoquinolinone, and naphthyridinone with aryl boronic acids. The ultrasonic and rotary evaporation treatment of the mixture of aq. Cu(BF₄)₂ and activated carbon in methanol afforded a novel Cu(II)-catalyst, which is air-stable and can be effectively applied in the Chan-Lam coupling reaction. The products of N-arylation were isolated in good to excellent yields at low catalytic loading. And Cu(BF₄)₂/AC also showed good reusability.

Hierarchical HCF@NC/Co Derived from Hollow Loofah Fiber Anchored with Metal-Organic Frameworks for Highly Efficient Microwave Absorption

Hierarchical electromagnetic wave (EMW) absorption materials with a dielectric-magnetic dual-loss mechanism are promising candidates for highly efficient EMW attenuation. Herein, hierarchical dielectric-magnetic composite hollow carbon fiber@nitrogen-doped carbon/Co (HCF@NC/Co) was successfully synthesized via in situ growth of two-dimensional (2D) Co metal-organic framework (MOF) (ZIF-67) nanosheets on the surface of hollow loofah fiber (HLF), followed by a calcination process, where the aggregation of carbonized MOFs was effectively avoided to construct a homogeneous hierarchical one-dimensional structure. Based on the advantages of the carbon/Co dielectric-magnetic dual-loss mechanism that results in good impedance matching and multiple polarization loss arising from the extensive heterointerfaces (e.g., HCF-NC/Co, air-carbon, nitrogen-carbon, and Co-carbon interfaces), dipole active sites (e.g., doped N, Co particle, and crystalline defects in graphitic carbon), and hierarchical porous structures, optimal EMW absorption performance of HCF@NC/Co is achieved through regulating the calcination temperature and filler content, where the HCF@NC/Co calcinated at 700 °C exhibits a minimum reflection loss (RL_min) value of -50.14 dB with only 14% filler loading and 2.25 mm thickness, and the maximum effective absorption bandwidth (EAB_max) also reaches 7.36 GHz. Meanwhile, adjustable EAB can also be achieved by optimizing the sample thickness, making it applicable in a wider frequency region. It is expected that our prepared HCF@NC/Co might shed light on designing lightweight and highly efficient EMW MOF-derived EMW absorbing materials.

An electrochemical immunosensor for the detection of carcinoembryonic antigen based on Au/g-C3N4 NSs-modified electrode and CuCo/CNC as signal tag

Carcinoembryonic antigen levels in the human body reflect the conditions associated with a variety of tumors and can be used for the identification, development, monitoring, and prognosis of lung cancer, colorectal cancer, and breast cancer. In this study, an amperometric immunosensor with CuCo/carbon nanocubes (CuCo/CNC) as the signal label is constructed. The bimetal-doped carbon skeleton structure has a high specific surface area and exhibits good electrocatalytic activity. In addition, Au/g-C₃N₄ nanosheets (Au/g-C₃N₄ NSs) are used to modify the substrate platform, facilitating the loading of more capture antibodies. The reaction mechanism was explored through electrochemical methods, X-ray powder diffraction, X-ray photoelectron spectroscopy, and other methods. Kinetic studies have shown that CuCo/CNC have good peroxidase-like activity. In addition, the electrocatalytic reduction ability of CuCo/CNC on hydrogen peroxide can be monitored using amperometric i-t curve (- 0.2 V, vs. SCE), and the response current value is positively correlated with the CEA antigen concentration. The prepared electrochemical immunosensor has good selectivity, precision, and stability. The dynamic range of the sensor was 0.0001-80 ng/mL, and the detection limit was 0.031 pg/mL. In addition, the recovery and relative standard deviation in real serum samples were 97.7-103 % and 3.25-4.13 %, respectively. The results show that the sensor has good analytical capabilities and can provide a new method for the clinical monitoring of CEA.

Towards the development of the emerging process of CO2 heterogenous hydrogenation into high-value unsaturated heavy hydrocarbons

The emerging process of CO₂ hydrogenation through heterogenous catalysis into important bulk chemicals provides an alternative strategy for sustainable and low-cost production of valuable chemicals, and brings an important chance for mitigating CO₂ emissions. Direct synthesis of the family of unsaturated heavy hydrocarbons such as α-olefins and aromatics via CO₂ hydrogenation is more attractive and challenging than the production of short-chain products to modern society, suffering from the difficult control between C-O activation and C-C coupling towards long-chain hydrocarbons. In the past several years, rapid progress has been achieved in the development of efficient catalysts for the process and understanding of their catalytic mechanisms. In this review, we provide a comprehensive, authoritative and critical overview of the substantial progress in the synthesis of α-olefins and aromatics from CO₂ hydrogenation via direct and indirect routes. The rational fabrication and design of catalysts, proximity effects of multi-active sites, stability and deactivation of catalysts, reaction mechanisms and reactor design are systematically discussed. Finally, current challenges and potential applications in the development of advanced catalysts, as well as opportunities of next-generation CO₂ hydrogenation techniques for carbon neutrality in future are proposed.