Suppressing metal sintering under high‑temperature operating conditions remains a critical challenge for cobalt‑based catalysts applied in the reverse water‑gas shift (RWGS) reaction for CO2 hydrogenation. In this study, the Co‑SiO2 catalyst was synthesized by an organic‑acid‑assisted impregnation method employing citric acid. The incorporation of organic acids effectively enhanced metal‑support interactions and diminished the size of Co3O4 nanoparticles. After reduction at 600 °C, CoO species were stabilized in the organic‑acid‑modified catalysts, while metallic Co0 was generated over the conventional Co–SiO2 reference. Characterizations confirmed that the strengthened Co–SiO2 interfacial interaction restrained the deep reduction of CoO. Compared with the unmodified catalyst, the as‑prepared organic‑acid‑assisted catalyst exhibited improved activity and substantially prolonged catalytic stability during 600 min time‑on‑stream tests at 600 °C. Thermo-gravimetric analysis revealed negligible carbon deposition over the spent catalyst. This work offers a facile synthetic strategy for fabricating robust CoO‑based catalysts toward efficient CO2 conversion via the RWGS reaction.
Photocatalytic technology is a significant approach to addressing environmental pollution, highlighting the strategic importance of developing novel, high efficiency photocatalysts. This study prepares hierarchical PbBiO2Br/Mo2CTx composites via in situ hydrothermal growth of PbBiO2Br nanoflowers on MXene Mo2CTx nanosheets. Morphological and structural characterization confirms that PbBiO2Br nanoflowers encapsulate Mo2CTx nanosheets, forming a three-dimensional porous architecture. Photocatalytic degradation tests show the composite exhibits superior activity to pure PbBiO2Br for ciprofloxacin degradation: the 5 wt% Mo2CTx-loaded sample shows a degradation efficiency 4.3 times that of pristine PbBiO2Br and 9.4 times that of bare Mo2CTx, with a kinetic constant approximately 11.02 times that of pure PbBiO2Br and 25.15 times that of pure Mo2CTx. Steady-state/transient PL, EPR, and photoelectrochemical measurements demonstrate that the composite's photogenerated charge separation and migration efficiency are markedly enhanced. This is attributed to Mo2CTx acting as an electron reservoir to suppress charge recombination, while the unique hierarchical structure promotes interfacial charge transfer and exposes more active sites. A novel photocatalytic mechanism and antibiotic degradation pathway are proposed, providing important references for the development of MXene-based composite photocatalysts and their application in antibiotic degradation.Graphical Abstract The figure intuitively demonstrates the reaction mechanism and the superior photocatalytic performance of 5Mo
Thiazole-5-ones were synthesized using a novel and efficient one-pot three-component reaction involving acetophenones and/or aromatic aldehyde derivatives, ethyl chloroacetate and thiosemicarbazide, facilitated by a newly reported heterogeneous nanocatalyst formulated as Fe3O4/cellulose/Zn-MOF. This protocol yielded the desired products with excellent yields (90-98%) during a simple procedure in the absence of solvent within brief reaction times (10-15 min). The nanocatalyst was easily recovered using an external magnet and retained high catalytic efficiency over five consecutive cycles. The structural integrity of the recovered catalyst was confirmed by FT-IR and XRD analysis, demonstrating its potential for sustainable and green chemical transformations. The combination of high efficiency, excellent product yields, straightforward work-up, catalyst recyclability, and solvent-free conditions highlights the potential of the Fe3O4/cellulose/Zn-MOF nanocatalyst as a practical and sustainable catalytic system for the synthesis of thiazole-5-one derivatives. The structure of the synthesized heterogeneous catalyst was thoroughly characterized using various spectroscopic techniques including SEM, TEM, XRD, EDX/Mapping, VSM, TGA, and FT-IR.
A series of NiFex/CeO2 bimetallic catalysts was prepared by the incipient wetness impregnation method and subsequently applied for CO2 methanation. The CO2 methanation activity of the NiFex/CeO2 catalyst is significantly enhanced by the introduction of an appropriate amount of Fe. At 280 degrees C, 100 kPa and 24,000 mL/(g & centerdot;h), the NiFe0.3/CeO2 catalyst exhibits a CO2 conversion of 88.6%. Characterization of the catalysts was performed by N2 adsorption-desorption, XRD, CO2-TPD, H2-TPR and XPS techniques. The results indicate that the introduction of Fe promotes the reducibility of NiO in the catalyst but decreases the number of surface basic sites. A strong electronic interaction between Fe and Ni is observed: Fe3+ donates electrons to Ni2+ in the calcined catalyst, while after reduction, the formation of a Ni-Fe alloy leads to electron donation from Ni to Fe. The improved catalytic activity of the NiFex/CeO2 catalysts is attributed to the electronic interaction between Fe and Ni, which modifies the charge density of Ni and enhances the intrinsic activity of Ni sites.Graphical Abstract High CO2 methanation activity was achieved over NiFex/CeO2 bimetallic catalyst, in which a strong electronic interaction exists between Fe and Ni.
