A hollow void catalyst of Co@C(Z-d)@void@CeO2 for enhancing the performance and stability of the Fischer-Tropsch synthesis

To enhance the catalyst performance of Fischer-Tropsch synthesis (FTS), removing the mass-transfer restriction in the catalysis synthesis is essential. Although the core-shell nanostructures can improve the activity and stability of the catalyst, they can restrict the reactants' diffusion towards the active sites and the transfer of the products from these sites in FTS. Creating an adequate porosity between the core and the outer shell of the catalyst structure can tackle this issue. In this work, the synthesized cobalt-based nano-catalyst is encapsulated with two shells and a middle porous shell. The first shell is a carbon shell at the core of the catalyst derived from ZIF-67, the second one is the outer shell of ceria, and the middle porous shell is formed by removing the sacrificial silica shell through the etching technique. The characterization and performance tests represent significant evidence of the etching treatment's impact on the FTS catalyst performance. Besides, molecular dynamics simulation is also utilized to clarify its effect. The FTS catalytic performance is enhanced more than 2 times with the etched catalyst versus the catalyst without it at 17.5 bar and a (H2/CO) ratio of 1.2. In addition, not only does the etched catalyst with high porosity play the role of a nanoreactor and intensify its catalytic performance, but it also has higher stability.

Design and synthesis of high performance magnetically separable exfoliated g-C3N4/γ-Fe2O3/ZnO yolk-shell nanoparticles: a novel and eco-friendly photocatalyst toward removal of organic pollutants from water

Herein, a new visible-light active exfoliated g-C3N4/γ-Fe2O3/ZnO yolk-shell nanoparticles (NPs) was synthesized as a magnetically separable photocatalyst. For an in-depth understanding of the magnetic photocatalyst's structural, morphological, and optical properties, the products were extensively characterized with FT-IR, XRD, TEM, HRTEM, FESEM, EDS, EDS-mapping, VSM, DRS, EIS, and photocurrent. The photocatalyst was then utilized to degrade Levofloxacin (LEVO) and Indigo Carmine (IC) by visible light at room temperature. The exfoliated g-C3N4/γ-Fe2O3/ZnO yolk-shell NPs photocatalyst revealed 80% and 95.6% degradation efficiency for Levofloxacin and Indigo Carmine within 25 and 15 min, respectively. In addition, the optimal factors such as concentration, loading of photocatalyst, and pH were also assessed. Levofloxacin degradation mechanistic studies showed that electrons and holes significantly contribute to the photocatalytic process of photocatalyst degradation. In addition, after 5 times regeneration, exfoliated g-C3N4/γ-Fe2O3/ZnO yolk-shell NPs remained as an excellent magnetic photocatalyst for the eco-friendly degradation of Levofloxacin and Indigo Carmine (76% and 90%), respectively. The superior photocatalytic performance of exfoliated g-C3N4/γ-Fe2O3/ZnO yolk-shell nanoparticles (NPs) was mostly ascribed to the synergistic advantages of stronger visible light response, larger specific surface area, and the more effective separation and transfer of photogenerated charge carriers. Based on these results, the highly effective magnetic photocatalyst achieved better results than numerous studied catalysts in the literature. The degradation of Levofloxacin and Indigo Carmine under environmentally friendly conditions can be achieved using exfoliated g-C3N4/γ-Fe2O3/ZnO yolk-shell NPs (V) as an efficient and green photocatalyst. The magnetic photocatalyst was characterized by spectroscopic and microscopic methods, revealing a spherical shape and particle size of 23 nm. Additionally, the magnetic photocatalyst could be separated from the reaction mixture by a magnet without significantly reducing its catalytic activity.

Rice straw ash extract/glycerol: an efficient sustainable approach for Knoevenagel condensation

WERSA/glycerol is described as a powerful combination for the green approach of the Knoevenagel reaction, without any additional catalyst, base or promoter.

Palladium-catalyzed phosphorylation of arylsulfonium salts with P(O)H compounds via C–S bond cleavage

Herein we report a novel palladium-catalyzed phosphorylation of arylsulfonium salts with P(O)H compounds via C–S bond cleavage under mild conditions.

Design of Carbon-carbon and Carbon-heteroatom Bond Formation Reactions under Green Conditions

:

The development of C-C and C-heteroatom (C-N, C-O and C-P) bond reactions is a field of significant interest and has received momentous attention in modern organic chemistry. These reactions have been exploited in the synthesis of pharmaceuticals, agrochemicals and molecules of interest in materials science. With the increasing awareness of global warming and the use of renewable energies, it is of paramount importance to reduce the usage of hazardous chemicals in both industrial and academic research and to achieve a healthier environment through green practices. Green chemistry is a rapidly emerging approach that shows us a path for the sustainable growth of future science and technologies. In the recent past, healthy growth has been recorded in a number of organic reactions in aqueous media, which are environment-friendly and energy conserving. This review documents the literature on the development of green methodologies involving the design of C-C, C-O, C-N and C-P bond formations of coupling and condensed reactions. It emphasizes the exceptional practices and important advances achieved using alternative green tools, such as microwave (MW), high-speed ball milling (HSBM) and ultrasound irradiation techniques, and a variety of reusable catalysts and green solvents, with attention to water.

Magnetic MCM-41 nanoparticles as a support for the immobilization of a palladium organometallic catalyst and its application in C–C coupling reactions

An organometallic catalyst of palladium has been immobilized on magnetic MCM-41 nanoparticles and used for C–C coupling reactions. The products were obtained in high yields and good TOF values which were indicate the high efficiency of this catalyst.

PdII Immobilized on Ferromagnetic Multi-Walled Carbon Nanotubes Functionalized by Aminated 2-Chloroethylphosphonic Acid with S-Methylisothiourea (FMMWCNTs@CPA@SMTU@PdII NPs) Applied as a Highly Efficient and Recyclable Nanostructured Catalyst for Suzuki–Miyaura and Mizoroki–Heck Cross-Coupling Reactions in Solvent-Free Conditions

The new ferromagnetic nanostructured FMMWCNTs@CPA@SMTU@PdII NPs (IV) as an eco-friendly heterogeneous nanocatalyst with a particle size of ~20–30nm reported earlier by our group has been found to be very effective for Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions at ambient temperature. The procedure has been applied for a wide range of aryl halides, arylboronic acids, and alkenes. The magnetic separation by an external magnetic field, mild reaction conditions, and catalyst reusability up to four times without significant decrease in catalytic activity (reduced catalytic activity from 11 to 18% in the fifth, sixth, and seventh cycles) made the present method sustainable and economically viable for C–C cross-coupling reactions.

CoII immobilized on an aminated magnetic metal–organic framework catalyzed C–N and C–S bond forming reactions: a journey for the mild and efficient synthesis of arylamines and arylsulfides

The catalytic activity of Fe₃O₄@AMCA-MIL53(Al)-NH₂-Co^II NPs as a novel and inexpensive catalyst was investigated in the C–N and C–S cross coupling reactions.