Catalysis Communications最新文献

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.

The 2,4-dichlorophenoxyacetic acid (2,4-D) is an agrochemical used to remove weeds in paddy fields. Due to the toxicity associated, 2,4-D containing water needs treatment. Thus, herein, a sunlight-responsive ZrO₂-Bi₂O₃ photocatalyst was prepared by green synthesis using cow urine and tested for its efficiency in degrading 2,4-D. The prepared ZrO₂-Bi₂O₃ was then characterized in detail. The experimental results showed that 40% ZrO₂-Bi₂O₃ showed the best photocatalytic activity and stable even after five cycles of reuse. Furthermore, the sustainability of the studied technique that was analysed by the newly developed “weightage-based ranking method” showed that the present work addressed 14 of 17 SDGs.

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.

The study explored the simultaneous use of peroxydisulfate (PS) and hydrogen peroxide (H₂O₂) in the electrocoagulation process for efficient removal of direct red 89 (DR89) from aqueous solutions. The study examined the effect of various parameters, including electrode type, electrolyte type and dosage, initial pH, current density, PS and H₂O₂ dosage, and initial DR89 concentration. The highest efficiency was achieved in acidic conditions using AL-Fe electrodes and Na₂SO₄ as a supporting electrolyte and applying the highest studied current density (20 mA/cm²). The study found that DR89 removal followed second-order reaction kinetics, and singlet oxygen played a significant role in DR89 degradation.

The current study explores the hydrodeoxygenation (HDO) of pine sawdust derived pyrolysis bio-oil and co-processing of raw bio-oil with Vacuum Gas Oil (VGO) in a micro-activity testing (MAT) unit. The catalytic performance of mono- and bi-metallic catalysts were tested for bio-oil upgrading. Notably, FeCo (2:1)/Al₂O₃ catalysts exhibited superior HDO activity compared to their mono-metallic counterparts. Co-processing of raw bio-oil (2–10 wt%) with VGO led to a notable increase in gasoline yield of ∼48% with a 6 wt% blend. Maximum conversion was achieved with 8 wt% blend, further increasing the proportion, conversion decreased significantly affecting the product distribution.

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 present work reports for the first time the use of Decaschistia trilobata Wight. as a reducing agent for synthesis of silver nanoparticles (AgNPs). D. trilobata is an endemic shrub and grows seasonally in dry tropical biome, evergreen forests in hilly terrain of western ghats. One of the most fascinating metallic nanoparticles utilized in biological applications is AgNPs. In present work green synthesis of stable silver nanoparticles using Decaschistia trilobata (Dt-AgNPs) leaves extract as well as quantitative analysis of phytochemicals. The synthesized Dt-AgNPs were characterized and evaluated for their antioxidant anti-inflammatory, antibacterial and dye reduction.

Photocatalytic hydrogen generation is a viable option among strategies to mitigate the energy crisis. This study investigates visible-light-driven H₂ generation using Ag-doped twin crystal Cd_xZn_1-xS photocatalysts synthesized through a solvothermal process. Ag nanoparticles induce Surface Plasmon Resonance (SPR), enhancing photo-response. Twin crystal 1 wt% Ag-doped Cd_0.5Zn_0.5S photocatalyst exhibits significant H₂ evolution at 2458 μmol/g_cat.h under visible light. Enhanced performance is attributed to dual-function Ag nanoparticles: SPR-enhanced light absorption, efficient electron transfer to the Cd_0.5Zn_0.5S conduction band, and the twin crystal structure facilitating electron-hole pair separation. Emphasis on optimal Ag loading and the crucial role of SPR in elevating photocatalyst efficiency.

We report the recent advances in heterogeneous catalysis with emphasis on electron configurations as driving forces of the catalytic reactions. Several descriptors, including size, shape, surface area, oxygen vacancies, hydrogen spill-over, and porosity have been extensively reported. Whereas most catalysis researchers avoid studying the effect of electronic property due to the difficulty in elucidating its effects in heterogeneously catalyzed reactions. Although this topic is extensively explored in homogeneous systems, there is no unifying paradigm for heterogeneous systems. We focus on the progress made and draw the reader's attention to the possibility that electron manipulation could be used to improve catalysis.