Post synthesis alumination of KIT-6 materials with Ia3d symmetry and their catalytic efficiency towards multicomponent synthesis of 1H-pyrazolo[1,2-]phthalazine-5,10-dione carbonitriles and carboxylates

Encapsulation of Imidazole into Ce-Modified Mesoporous KIT-6 for High Anhydrous Proton Conductivity

Imidazole molecules entrapped in porous materials can exhibit high and stable proton conductivity suitable for elevated temperature (>373 K) fuel cell applications. In this study, new anhydrous proton conductors based on imidazole and mesoporous KIT-6 were prepared. To explore the impact of the acidic nature of the porous matrix on proton conduction, a series of KIT-6 materials with varying Si/Al ratios and pure silica materials were synthesized. These materials were additionally modified with cerium atoms to enhance their Brønsted acidity. TPD-NH3 and esterification model reaction confirmed that incorporating aluminum into the silica framework and subsequent modification with cerium atoms generated additional acidic sites. UV-Vis and XPS identified the presence of Ce3+ and Ce4+ in the KIT-6 materials, indicating that high-temperature treatment after cerium introduction may lead to partial cerium incorporation into the framework. EIS studies demonstrated that dispersing imidazole within the KIT-6 matrices resulted in composites showing high proton conductivity over a wide temperature range (300-393 K). The presence of weak acidic centers, particularly Brønsted sites, was found to be beneficial for achieving high conductivity. Cerium-modified composites exhibited conductivity surpassing that of molten imidazole, with the highest conductivity (1.13 × 10-3 S/cm at 393 K) recorded under anhydrous conditions for Ce-KIT-6. Furthermore, all tested composites maintained high stability over multiple heating and cooling cycles.

Importance of the polarity on nanostructured silica materials to optimize the hydrolytic condensation with molecules related to CO2 adsorption

The present work reports the changes for the mesoporous materials SBA-15 and KIT-6 associated with the structural, textural, and chemical properties when they are subjected to thermo-alkaline treatment. Despite the fact that the silica supports have not a strong affinity for CO₂ adsorption, the adsorption enthalpy profiles (ΔH_ads) reported that the substrates subjected to the thermo-alkaline treatment (S15H and K6H) have a greater energetic affinity towards CO₂ capture if compared to the precursory solids (S15 and K6). The ΔH_ads is - 26.7 kJ mol^-1 at 0.15 mmol g^-1 by supported S15H and K6H while the ΔH_ads is - 20. 7 kJ mol^-1 and - 18.7 kJ mol^-1 by K6 and S15, respectively, at the same CO₂ coverage. Furthermore, the CO₂ adsorption performances by the hydrolytic condensation between silica supports and the N´- (3-trimethoxysilylpropyl)diethylenetriamine (NAEPTES) or 3-aminopropiltriethoxysilane (APTES) are presented and it can be seen that the best performer for CO₂ adsorption is reported for the S15HN since it is able to absorb 0.93 mmol at 0.15 atm at 318 K. Thereby, the outcomes show that the effects of porous curvature and the magnitude of the amine species are parameters to be considered, as well as the thermo-alkaline treatment, in order to improve the subsequent surface reactions on silica supports. The materials were characterized by XRD, TEM, and N₂ adsorption at 77 K, NIR, and pyridine thermodesorption using Fourier Transform Infrared Spectroscopy (FTIR-Py), NMR for ²⁹Si and ¹³C, DSC, and CO₂ adsorption.

Lipase-mediated multicomponent synthesis of 1H-Pyrazolo[1,2-b]phthalazine-5,10-dione derivatives in a binary solvent medium

A new method for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives via lipase from the Aspergillus niger-catalyzed multicomponent reaction of aldehydes, malononitrile, and phthalhydrazide is reported herein for the first time. This novel method holds several advantages, including its efficiency, environmental friendliness, simple workup procedure, and good yield (70-86%). The effects of temperature, organic solvents, and water content were investigated. This protocol has the potential to replace traditional chemical synthesis routes for the synthesis of nitrogen-containing heterocyclic compounds.

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

Heterocycles have been found to be of much importance as several nitrogen- and oxygen-containing heterocycle compounds exist amongst the various USFDA-approved drugs. Because of the advancement of nanotechnology, nanocatalysis has found abundant applications in the synthesis of heterocyclic compounds. Numerous nanoparticles (NPs) have been utilized for several organic transformations, which led us to make dedicated efforts for the complete coverage of applications of metal nanoparticles (MNPs) in the synthesis of heterocyclic scaffolds reported from 2010 to 2019. Our emphasize during the coverage of catalyzed reactions of the various MNPs such as Ag, Au, Co, Cu, Fe, Ni, Pd, Pt, Rh, Ru, Si, Ti, and Zn has not only been on nanoparticles catalyzed synthetic transformations for the synthesis of heterocyclic scaffolds, but also provide an inherent framework for the reader to select a suitable catalytic system of interest for the synthesis of desired heterocyclic scaffold.

Kinetics of Fischer–Tropsch Synthesis in a 3-D Printed Stainless Steel Microreactor Using Different Mesoporous Silica Supported Co-Ru Catalysts

Fischer–Tropsch (FT) synthesis was carried out in a 3D printed stainless steel (SS) microchannel microreactor using bimetallic Co-Ru catalysts on three different mesoporous silica supports. CoRu-MCM-41, CoRu-SBA-15, and CoRu-KIT-6 were synthesized using a one-pot hydrothermal method and characterized by Brunner–Emmett–Teller (BET), temperature programmed reduction (TPR), SEM-EDX, TEM, and X-ray photoelectron spectroscopy (XPS) techniques. The mesoporous catalysts show the long-range ordered structure as supported by BET and low-angle XRD studies. The TPR profiles of metal oxides with H2 varied significantly depending on the support. These catalysts were coated inside the microchannels using polyvinyl alcohol and kinetic performance was evaluated at three different temperatures, in the low-temperature FT regime (210–270 °C), at different Weight Hourly Space Velocity (WHSV) in the range of 3.15–25.2 kgcat.h/kmol using a syngas ratio of H2/CO = 2. The mesoporous supports have a significant effect on the FT kinetics and stability of the catalyst. The kinetic models (FT-3, FT-6), based on the Langmuir–Hinshelwood mechanism, were found to be statistically and physically relevant for FT synthesis using CoRu-MCM-41 and CoRu-KIT-6. The kinetic model equation (FT-2), derived using Eley–Rideal mechanism, is found to be relevant for CoRu-SBA-15 in the SS microchannel microreactor. CoRu-KIT-6 was found to be 2.5 times more active than Co-Ru-MCM-41 and slightly more active than CoRu-SBA-15, based on activation energy calculations. CoRu-KIT-6 was ~3 and ~1.5 times more stable than CoRu-SBA-15 and CoRu-MCM-41, respectively, based on CO conversion in the deactivation studies.

An efficient copper catalyzed 3D mesoporous aluminosilicate for the synthesis of dibenzodiazonines in the Ullmann cross-coupling reaction

CuO distribution in the aluminosilicate framework and acidic sites play a multifunctional role in the reaction. 13H-Dibenzo[1,4]diazonine has been synthesized by using a 6 wt% CuO/Al-KIT-6 catalyst using ethanol as solvent.

Preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones using ZrO2 nanoparticles as a catalyst under solvent-free conditions

Zirconium oxide nanoparticles are an efficient catalyst for the preparation of 1

Rh/Ni wet-impregnated Ia3d mesostructured aluminosilicate and r-GO catalysts for hydrodeoxygenation of phenoxybenzene

Rh/Ni bimetallic supported bifunctional 3D porous aluminosilicate and Rh/Ni supported reduced graphene oxide (r-GO) catalysts were synthesised and their structural properties evaluated by XRD, BET-surface area, FT-IR, NH₃-TPD, H₂-TPR, ICP-OES, HRTEM-EDAX and XPS analysis.

Synthesis and characterization of dicationic 4,4′-bipyridinium dichloride ordered mesoporous silica nanocomposite and its application in the preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives

Application of SBA@BiPy²⁺ 2Cl⁻ nanocomposite as a novel environmentally safe heterogeneous nanoreactor for the one-pot solvent-free synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives.

Nano Brönsted solid acid containing double-charged diazoniabi-cyclo[2.2.2]octane chloride supported on nano rice husk silica: an efficient catalyst for the one-pot synthesis of phthalazine compounds

In the present work, amorphous silica nanoparticles were synthesized from low-cost rice husk ash (RH–SiO₂).

Enhanced catalytic performance for metathesis reactions over ordered tungsten and aluminum co-doped mesoporous KIT-6 catalysts

W-Al-KIT-6 (Si/Al = 10) with high dispersion of active W species and moderate acidity shows highest activity and selectivity to propene.

Efficient One‐Pot Solvent‐Free Synthesis of 1H‐Pyrazolo[1,2‐b]phthalazine‐5,10‐diones Catalyzed by Sulfonic Acid Functionalized Nanoporous Silica (SBA‐Pr‐SO3H)

A green protocol has been developed for the synthesis of 1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐diones by one‐pot cyclocondensation reaction of phthalhydrazide, aromatic aldehydes, and malononitrile or ethyl cyanoacetate using sulfonic acid functionalized SBA‐15 (SBA‐Pr‐SO3H) as a heterogeneous solid acid catalyst under solvent‐free conditions.

Progress of the synthesis of condensed pyrazole derivatives (from 2010 to mid-2013)

Condensed pyrazole derivatives are important heterocyclic compounds due to their excellent biological activities and have been widely applied in pharmaceutical and agromedical fields. In recent years, numerous condensed pyrazole derivatives have been synthesized and advanced to clinic studies with various biological activities. In this review, we summarized the reported synthesis methods of condensed pyrazole derivatives from 2010 until now. All compounds are divided into three parts according to the rings connected to pyrazole-ring, i.e. [5, 5], [5,F 6], and [5, 7]-condensed pyrazole derivatives. The biological activities and applications in pharmaceutical fields are briefly introduced to offer an orientation for the design and synthesis of condensed pyrazole derivatives with good biological activities.

The enhanced adsorption of sulfur compounds onto mesoporous Ni-AlKIT-6 sorbent, equilibrium and kinetic analysis

High performance nickel supported on mesoporous AlKIT-6 (Si/Al=15, 25, 50, 100) sorbents were prepared by incipient wetness impregnation (IWI) with ultrasonic aid for adsorptive desulfurization of commercial diesel and simulated fuels. The sorbents were characterized by N2 adsorption-desorption, XRD, NH3-TPD, Py-FT-IR, HRTEM, SEM and atomic absorption spectroscopy techniques. The analysis results confirmed that Aluminum atoms entered the framework and 20%Ni-AlKIT-6(15) can still retain three dimensional structure of AlKIT-6(15) and Ni is highly dispersed in the support. The kinetic pseudo second-order model and Langmuir isotherm are shown to exhibits the best fits of experimental data for the adsorption of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over AlKIT-6 and 5-30%Ni-AlKIT-6. Intraparticle diffusion and steric hindrance were the rate controlling step of the adsorption of T and DBT over AlKIT-6(15) and 20%Ni-AlKIT-6(15) as verified through the intraparticle diffusion model. The characterization of regenerated 20%Ni-AlKIT-6(15) revealed that three-dimensional cubic Ia3d symmetric structure was maintained in the sorbent after 6 successive desulfurization-regeneration cycles.