Enabled by recent advances in symmetry and electronic structure, researchers have observed signatures of unconventional threefold degeneracies in tungsten carbide, challenging a longstanding paradigm in nodal semimetals.

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The grain contamination by Aspergillus spp. has been a serious issue. This study exhibited the excellent antifungal effects of the essential oil compounds (EOCs) geraniol and citral against common grain pathogens (A. flavus and A. ochraceus) in vitro and in situ. The inhibitory mechanisms were also evaluated from the perspective of cell membrane permeability, reactive oxygen species (ROS) generation, and Aspergillus spp. growth-related gene expression. Meanwhile, the combined effects of EOCs in the vapor phase and modified atmosphere packaging (MAP) were examined to find an alternative preservation method for controlling Aspergillus spp. The results indicated that citral exhibited the antifungal activity mainly by downregulating the sporulation- and growth-related genes for both pathogens. Geraniol displayed inhibitory effectiveness against A. flavus predominantly by inducing the intracellular ROS accumulation and showed toxicity against A. ochraceus principally by changing cell membrane permeability. Furthermore, the synthetic effects of EOCs and MAP (75% CO2 and 25% N2) induced better grain quality than the current commercial fumigant AlP. These findings reveal that EOCs have potential to be a novel grain preservative for further application.

Metal organic framework (MOF) derivatives, porous N-doped carbons (CN), can be used as catalyst carriers owing to their excellent structural properties. The microstructures of MOF-derived carbon materials are affected considerably by the atmosphere in which the parent MOFs are pyrolyzed. In this study, a hierarchically porous N-doped carbon hybrid of carbon nanotubes and a porous carbon framework (denoted CN-H) was fabricated by pyrolysis in a H2/Ar atmosphere followed by acid etching, and subsequently, a Pd@CN-H catalyst was synthesized by the addition of Pd nanoparticles on the porous N-doped carbon support. The pyrolysis atmosphere and etching treatment significantly affected the morphology, specific surface area, meso/macropore ratio, and composition of the porous N-doped carbon materials, as well as the catalytic properties of the Pd@CN catalysts for the selective hydrogenation of phenol to produce cyclohexanone. Nitrogen adsorption–desorption measurements and inductively coupled plasma atomic absorption spectroscopy analyses confirmed that pyrolysis in a H2/Ar atmosphere and acid etching significantly increased the number of meso/macropores in Pd@CN-H, thus enhancing the Pd loading and phenol adsorption. As a result of the increased porosity, Pd loading, and phenol adsorption, the cyclohexanone selectivity and phenol conversion were improved. Furthermore, the as-fabricated Pd@CN-H catalyst displayed good reusability in recycling tests. These results provide insights into the synthesis of MOF-derived hybrid carbon materials and their possible utilization in catalysis.

Covalent organic frameworks (COFs) have emerged as an excellent support for heterogeneous catalysis due to their regular pore structure and high specific surface area. Herein, a series of porous TpPa-1 with different morphologies and structures were achieved by adjusting the ratio of water to acetic acid in the solvent-thermal process,

No abstract

Zeolite imidazolate frameworks (ZIFs) derivatives, porous N-doped carbon (CN) materials, show outstanding performance when used as catalyst supports. The characteristics of ZIFs affect significantly the microstructure of CN. In this work, a series of CN materials were fabricated through direct pyrolysis of Zn/Co-ZIFs and Pd@ CN catalysts were achieved by loading Pd nanoparticles. The results underline that the Co content in Zn/Co-ZIFs influences considerably the properties of CN and the catalytic activity of Pd@CN for the phenol hydrogenation to cyclohexanone. N 2 adsorption−desorption, CO 2 -TPD, and ICP analyses confirm that the increase of Co in ZIFs can enhance significantly the mesoporous ratio of CN for improving the loading and dispersion of Pd and increase the basic sites of CN materials for improving the phenol adsorption. As a result, significantly enhanced phenol conversion with similar cyclohexanone selectivity is achieved. These findings provide deep insights for the fabrication of ZIF-derived CN materials and their applications in catalysis.

For the first time, few-layer Ti3C2T x (FL-Ti3C2T x ) supporting highly dispersed nano-Ni particles with an interconnected and interlaced structure was elaborated through a self-assembly reduction process. FL-Ti3C2T x not only acts as a supporting material but also self-assembles with Ni2+ ions through the electrostatic interaction, assisting in the reduction of nano-Ni. After ball milling with MgH2, Ni30/FL-Ti3C2T x (few-layer Ti3C2T x supported 30 wt % nano-Ni via self-assembly reduction) shows superior catalytic activity for MgH2. For example, MgH2-5 wt % Ni30/FL-Ti3C2T x can release approximately 5.83 wt % hydrogen within 1800 s at 250 °C and absorb 5 wt % hydrogen within 1700 s at 100 °C. The combined effects of finely dispersed nano-Ni in situ-grown on FL-Ti3C2T x , large specific area of FL-Ti3C2T x , multiple-valence Ti (Ti4+, Ti3+, Ti2+, and Ti0) derived from FL-Ti3C2T x , and the electronic interaction between Ni and FL-Ti3C2T x can explain the superb hydrogen storage performance. Our results will attract more attention to the elaboration of the metal/FL-Ti3C2T x composite via self-assembly reduction and provide a guideline to design high-efficiency composite catalysts with MXene in hydrogen storage fields.