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The mechanism of a solvent consisting of choline chloride and glycerol (ChCl/GLY) for extracting phenolic compounds from coal tar was theoretically studied using density functional theory calculations and molecular dynamics simulations. The thermodynamic properties, interaction essence, and molecular dynamics properties of the extraction system were investigated, as well as the influence of ChCl/GLY on the vibration spectra of phenolic compounds. The results show that the solvation free energy of phenolic compounds in ChCl/GLY is more negative than that in coal tar, leading to the spontaneous transfer of phenolic compounds from coal tar to ChCl/GLY. The electrostatic and dispersion interactions between phenolic compounds and ChCl/GLY have similar significance in the extraction process, with interaction energies ranging from −46 to −53 kJ mol−1. The mixing of phenolic compounds with ChCl/GLY has minimal impact on their internal molecular structure, however, it does reduce the diffusion coefficients of each component in ChCl/GLY and shortens the lifetime of hydrogen bonds in both phenolic compounds and ChCl/GLY. The first shell of each phenolic compound is surrounded by 1.15 chloride ions. Following dissolving in ChCl/GLY, the stretching vibration peaks of phenolic compounds, namely the –OH and C–H/–CH3 regions, undergo a shift. The results enhance comprehension of the extraction process of phenolic compounds by DES. [ABSTRACT FROM AUTHOR]

Attapulgite, as a versatile clay, can be constructed as an integral monolith through a 3D printing strategy to promote practical catalytic applications. Herein, we successfully realized 3D printing of attapulgite monoliths with the superior printing effect via a direct ink writing (DIW) technique. The influence of thermal treatment on DIW attapulgite monoliths was also systematically investigated at different calcination temperatures. Wherein, related characteristic changes of DIW attapulgite monoliths under thermal treatment were examined, including surface morphology, chemical properties, solidification shrinkage, rheological behaviors and compressive strength. Additionally, DIW attapulgite monoliths under thermal treatment were probed for the selective catalytic reduction of NOx with NH3 (NH3-SCR) performance, in which 3D-ATP-400 can exhibit superior low-temperature NH3-SCR activity with almost 100% NOx conversion and N2 selectivity in the range of 40–70 °C. This study can provide a facile strategy for the design and preparation of 3D-printed attapulgite monoliths with superior low-temperature NH3-SCR performance under thermal treatment. [ABSTRACT FROM AUTHOR]

High-entropy crystalline materials are attracting more attention. In principle, high-entropy metal carbides (HMCs) that contain five or more metal ions, possess more negative free energy value during catalysis. But its preparation is challenging because of the immiscibility of multi metal cations in a single carbide solid solution. Here, a rational strategy for preparing HMC is proposed via a coordination-assisted crystallization process in the presence of Br-based poly(ionic liquids). Through this method, Mo0.2W0.2V0.2Cr0.2Nb0.2C nanoparticles, with a single cubic phase structure, incorporated on porous carbon, are obtained (HMC@NC). By combination of well dispersed small particle size (∼4 nm), high surface area (∼270 m2 g−1), and high-entropy phase, HMC@NC can function as a promising catalyst for the dehydrogenation of ethylbenzene. Unexpected activity (EB conv.: 73%) and thermal stability (>100 h on steam) at 450 °C are observed. Such a facile synthetic strategy may inspire the fabrication of other types of HMCs for more specific tasks. [ABSTRACT FROM AUTHOR]

Here, a MoOx-T based catalyst was developed by a simple reduction of MoO3 precursors at different temperatures. Interestingly, a partially reduced MoOx-600 catalyst obtained by reducing the MoO3 precursor at 600 °C shows the co-existence of a mixture of different valence states (0, +4, ∼+6) of Mo, and as a result, provides a superior catalytic activity. [ABSTRACT FROM AUTHOR]

Herein, we designed and initiated a novel mechanochemical self-assembly protocol that realized a rapid and solvent-free construction of a series of highly porous CeWOx oxides with high specific surface areas up to 143 m2 g−1, and their catalytic activities were examined for selective catalytic reduction of NOx with NH3 (NH3-SCR). Experimental results revealed that Ce0.8W0.2Ox exhibited the broadest activity temperature window for NOx abatement (210–440 °C) and excellent resistance to SO2 and H2O poisoning under a high gas hour space velocity (GHSV = 125 000 h−1) on account of its high specific surface area, abundant acid and redox sites, as well as more exposed active sites. DFT calculations unveiled that the amount of W dopant significantly influenced the structure of active sites, and that Ce0.8W0.2Ox exhibited the lowest oxygen vacancy formation energy (0.84 eV) and the strongest NH3 binding ability (−1.55 eV). Furthermore, kinetics experimental results disclosed that the incorporation of mesopores into CeWOx induced the exposure of more active sites, thereby facilitating the access of reactants to more active sites and the adsorption and activation of ammonia species, thereafter promoting the catalytic performance of CeWOx catalysts. Therefore, this work not only introduces a new opportunity for fabricating a number of advanced porous materials, but also provides insight into the crucial role of mesopores and dopants in heterogeneous catalysis reactions. [ABSTRACT FROM AUTHOR]

Herein, we present a facile, sustainable, and highly efficient ionic liquid induced self-assembly protocol to construct a highly porous MnNbOx oxide with exceptionally high catalytic activity for NOx removal at low temperatures and excellent tolerance to H2O and SO2 poisoning. [ABSTRACT FROM AUTHOR]

Mesoporous metal oxides with optimized porosity and active surfaces usually exhibit unexpected performance in many applications. However, sacrificial templates and complicated processes are generally required to generate mesopores. Herein, we discover the bifunctional templating talent of polyoxometalates (POMs) for generating not only mesopores but also reactive surfaces in metal oxides, and a facile, recyclable, and general method is reported. By mechanochemical ion-sharing between metal salts and POMs, metal precursors undergo pyrolysis around large POM clusters, which can incorporate abundant mesopores into metal oxides (e.g., Co3O4, Fe3O4, NiO, La2O3, MnO2, CeO2, ZrO2, and CuO) with ultrahigh specific surface areas (up to 210 m2 g−1) after simply being recycled by water washing. Unexpectedly, the oxidative feature of POMs naturally contributes to the formation of high valence metal cations on the material surface. As an example, the Co3O4 sample with both mesopores and enriched surface Co3+ species was more active than Co3O4 derived from a silica template (T100 = 200 °C) and commercial Co3O4 (T100 = 250 °C), in CO oxidation. The current strategy may provide a promising route for the commercialization of mesoporous metal oxides with preferred surface features. [ABSTRACT FROM AUTHOR]

Mesoporous metal oxides (MOs) have attracted significant interest in heterogeneous catalysis due to their wide pore size distribution and high pore volume. Herein, we present a facile mechanochemical nanocasting strategy using aluminum hydroxide as the mesoporous structure-directing agent, which overcomes the drawbacks associated with wet template-assisted methods. In this procedure, by simply grinding a mixture of commercial aluminum hydroxide and MO precursors, a series of mesoporous MOs with high specific surface areas and narrow pore size distributions have been constructed in a short time (e.g., Fe2O3, 280 m2 g−1; Co3O4, 155 m2 g−1; CeO2, 192 m2 g−1; ZrO2, 170 m2 g−1; CuOx–CeOy, 177 m2 g−1; FeOx–CeOy, 170 m2 g−1; CoOx–CuOy–CeOz, 154 m2 g−1; CoOx–FeOy–CeOz, 133 m2 g−1). It is expected that this strategy may open up new opportunities for fabricating a number of advanced porous materials with abundant porosity in the near future. [ABSTRACT FROM AUTHOR]

Herein, we present a facile, sustainable, and highly efficient ionic liquid induced self-assembly protocol to construct a highly porous MnNbOx oxide with exceptionally high catalytic activity for NOx removal at low temperatures and excellent tolerance to H2O and SO2 poisoning. [ABSTRACT FROM AUTHOR]

Here, a MoO x -T based catalyst was developed by a simple reduction of MoO 3 precursors at different temperatures. Interestingly, a partially reduced MoO x -600 catalyst obtained by reducing the MoO 3 precursor at 600 °C shows the co-existence of a mixture of different valence states (0, +4, ∼+6) of Mo, and as a result, provides a superior catalytic activity.

Herein, we present a facile, sustainable, and highly efficient ionic liquid induced self-assembly protocol to construct a highly porous MnNbOx oxide with exceptionally high catalytic activity for NOx removal at low temperatures and excellent tolerance to H2O and SO2 poisoning.