Catalysis Communications最新文献

Developing high-performance mercury removal catalysts is essential for addressing atmospheric mercury pollution. Notably, conventional mineral adsorbents are ineffective for high-temperature flue gases (>300 °C). In this study, confinement catalysis was utilized to modify CuMn₂O₄. Under the chlorine-free catalytic condition, the temperature window of T₉₅ was widened by 150 °C (for 50–400 °C) toward high-temperature. Mechanistic studies suggest that nanoconfinement effects significantly improve the catalytic performance. Molecular oxygen adsorption and activation capacity were dramatically enhanced, as demonstrated by NAP-XPS. The plentiful grain boundaries effectively adjust the defect species and electronic structure of the catalysts in favor of Hg⁰ catalysis, whereas the porous structure improves the reactant adsorption properties.

It is critical to enhance the photocatalytic performance of BiOBr through appropriate strategies. Two BiOBr samples with different water (W) and ethylene glycol (EG) solvents have been synthesized. BiOBr-EG presents a 3D nest-like morphology composed of nanoplates, prominently emphasizing (110) facets. In contrast, BiOBr-W displays 2D microplates with exposed (102) facets. Notably, BiOBr-EG exhibits a degradation rate 7.4 times faster and removal efficiency of Enrofloxacin (ENR) 2.2 times greater than that of BiOBr-W. Additional investigations reveal that ·O₂⁻ plays a dominant role in the degradation process. Finally, the degradation pathways are explored through DFT calculation and HPLC-MS methods.

The Cu-CuO-ZnO composite catalyst synthesized through the formic acid-assisted method, underwent thorough characterization via XRD, N₂ physisorption, TPR, TPD, TGA, XPS, and TEM. When applied to the selective dehydrogenation of 1,4-butanediol, this catalyst outperformed counterparts prepared through co-precipitation and impregnation methods. The superiority is attributed to the formic acid-assisted method yielding smaller Cu nanoparticles and some CuO species, undergoing in-situ reduction by dehydrogenation-generated H₂. This process results in nascent Cu nanoparticles, enhancing catalytic performance. Notably, the catalyst demonstrated remarkable stability over a 100 h time-on-stream without discrepancies, highlighting the robustness of the formic acid-assisted method for 1,4-butanediol dehydrogenation.

Catalytic ozonation has become one of the most promising technologies for wastewater treatment due to its high efficiency in the removal of organic pollutants. Three carbon materials (carbon nanotubes, graphene oxide and activated carbon) and five pharmaceutical compounds were selected for this study. All tested parent pollutants were easily degraded by single ozonation. In terms of mineralization, the presence of catalyst revealed to be necessary to enhance organic matter removal, and activated carbon (GAC) showing superior performance. To evaluate the effect of the water matrix, experiments were performed with ground water and wastewater and significant degradation of pollutants was achieved.

1,4-cyclohexanedimethanol (CHDM) is used as a high-value polyester monomer. On the basis of the catalysts of RuSn and Pd, the compound catalysts of RuSn and PdCe are prepared by adding the additive Ce to the Pd-based catalyst. The results showed that the yield of CHDM increased by 13.4% after the addition of Ce, indicating that Ce is conducive to the activation of HH and CO thus promoting the hydrogenation of carboxyl groups. Furthermore, the addition of Ce effectively slows down the coverage of the compound on the active component Pd, prolonging the lifespan of the catalyst.

CuO-Bi₂O₃/SiO₂@TiO₂ core-shell structured catalysts were prepared by stepwise precipitation method and used for the synthesis of 1, 4-butynediol (BYD) by the ethynylation of formaldehyde. The characterization results, by XRD, BET, SEM, TEM, TPD etc., revealed the TiO₂ content not only affecting the surface area of the catalysts and the partical size of the loaded CuO, but also affecting the electronic interactions with CuO. The activity tests showed that the catalyst with 20% TiO₂ calcined at 450 °C had a short activation time, with good activity with conversion 91% and BYD yield 73% after 6 h on line. The catalysts still maintained good catalytic activity and stability after 6 repeated uses. ICP data indicate that leaching of Cu active component after reaction is very low.

In this study, Fe₂O₃/C₃N₄/NH₂-MIL-125 ternary composite photocatalysts were synthesized. Their amino groups provided close bonding between these materials, facilitating the effective separation of electrons and holes. Besides, each component of Fe₂O₃/C₃N₄/NH₂-MIL-125 plays a crucial role. NH₂-MIL-125 provided a high surface area, C₃N₄ contributed to the primary photocatalytic activity, and Fe₂O₃ aided in enhancing light absorption, generating additional potential to produce hydroxyl radicals, thereby further enhancing photocatalytic activity. Moreover, the proportion of loaded Fe₂O₃ and C₃N₄ in the ternary material was investigated. It was found that Fe₂O₃/C₃N₄/NH₂-MIL-125 with a 1:1 ratio of Fe₂O₃ and C₃N₄ (FeCN1:1/NM125) exhibited excellent photocatalytic performance, in which RhB degradation reached 100% under visible light irradiation, conforming to first-order kinetics analysis with a reaction rate constant k of 0.0164 min⁻¹. Its efficiency was twice that of the binary catalyst C₃N₄/NH₂-MIL-125 or Fe₂O₃/NH₂-MIL-125, seven times that of the pristine catalyst C₃N₄, and ten times that of the pristine catalyst NH₂-MIL-125. Scavenger experiments showed that the degradation efficiencies were 52.57%, 55.51%, and 63.41%, respectively, indicating that three active species, namely superoxide radicals, holes, and hydroxyl radicals, made significant contributions to photocatalysis.

Molybdenum phosphide (MoP) has attracted increasing attention as a novel catalytic material for CO₂ reforming of methane in virtue of superior coke resistance, but its catalytic reactivity is still relatively low. This work for the first time improved the reforming activity of MoP via ZrO₂ modification. The Zr_0.01MoP catalyst with Zr/Mo molar ratio of 0.01 possessed much higher activity than bare MoP at 800–900 °C. Structural characterizations revealed that the introduction of ZrO₂ would decrease the particle size, modify the electronic structure and change the reducibility property of MoP, which may function together to deliver the higher activity.

Novel palladium based magnetic nanocatalyst was synthesized by the co-precipitation method and coated with silica and tea extract as stabilizing agent. Palladation onto the prepared nanocomposite was done to get ION-SiO₂/TE-Pd(0) catalyst. Our study is one of the limited number of studies reported for the catalytic denitrogenative coupling of arylbromide and arylhydrazine. This led to the construction of important substituted biaryls bearing various substituents with 82–92% yields. The synthesized nanocatalyst was characterized using structural and morphological characterization techniques. It was also observed that only 2 mol% of ION-SiO₂/TE-Pd(0) catalyst was sufficient for the catalysis and reusable upto six cycles.

The CuO-supported MCM-41 catalysts were prepared using a simple incipient wet impregnation method. The catalysts were investigated for hydrogenation of furfural to furfuryl alcohol synthesis. Among all the catalysts, the 2.5% CuO/MCM-41 catalyst shows the best catalytic performance with 92.5% conversion and 89% selectivity of furfuryl alcohol at 210 °C. The catalyst also demonstrated a high turnover frequency (TOF) of 154.4 h⁻¹. The 2.5% CuO/MCM-41 catalyst remained stable for up to 20 h during the time on stream.