3D Nanoporous FeAl-KIT-5 with a cage type pore structure: a highly efficient and stable catalyst for hydroarylation of styrene and arylacetylenes

A novel bimetallic nanoporous FeAl-KIT-5 catalyst with a cage type porous structure and a high surface area has been prepared for the hydroarylation of styrene and arylacetylenes to afford 1,1-diarylalkanes and 1,1-diarylalkenes, respectively. The catalyst was found to be highly active, and selective, affording a high yield of substituted alkanes and alkenes. The catalyst also showed much higher activity as compared to those of other nanoporous catalysts such as AlSBA-15, AlKIT-5, and FeKIT-5, and can be reused several times without much loss of its activity

Immobilization of chiral amide derived from (1R,2S)-(-)-norephedrine over 3D nanoporous silica for the enantioselective addition of diethylzinc to aldehydes

Chiral amide synthesized from (1R,2S)-(-)-norephedrine has been successfully immobilized onto three dimensional Ia3d cubic nanoporous material. The immobilization of the chiral amide has been confirmed by using various physiochemical techniques. The immobilized ligand has been screened for its catalytic activity in the enantioselective addition of diethylzinc to aromatic aldehydes. The immobilized catalyst was found to be highly active and selective, affording the final product chiral alcohols in 92% yield with a 95% ee at room temperature. The enantioselectivity of the immobilized catalyst is much higher than that of the homogenous catalyst (40% ee) at room temperature. In addition, the catalyst was stable and found to be purely heterogeneous and recyclable. The activity of the immobilized catalyst has been also investigated for the aromatic aldehydes with different electron donating and withdrawing groups. In addition, the electronic and steric effects of the substrates affecting the activity and the enantioselectivity of the catalysts were discussed in detail

Microwave-assisted synthesis of highly crystalline mesoporous hydroxyapatite with a rod-shaped morphology

Mesoporous hydroxyapatite (MHA) with a rod-shaped morphology has been successfully synthesized for the first time employing cetyltrimethylammonium bromide (CTAB) as a template and CaCl 2 and K 2HPO 4 as the precursors for hydroxyapatite under alkaline medium at the reaction temperature of 120°C via microwave method. The obtained material exhibits a disordered mesoporous structure with a high crystallinity and highly uniform rod-like morphology with an average size of ca. 25 nm in width and 100 nm in length

Ordered Mesoporous C-70 with Highly Crystalline Pore Walls for Energy Applications

Mesoporous materials with carbon framework structure can offer distinctive functionalities with tunable electronic or catalytic properties. Many synthetic routes including hard or soft templating approaches are developed for the fabrication of various ordered mesoporous carbon based materials which have demonstrated unique catalytic and energy storage properties. So far, most of these techniques deliver only mesoporous carbon with amorphous wall structures which limit their performance in many applications. Fullerenes exhibit unique structure and significant properties including superconductivity, electrochemical stability, and heat resistance. Herein, for the first time, the preparation of highly ordered mesoporous fullerene C-70 materials with tunable porous structure and controlled rod-shaped morphology through the thermal oligomerization of fullerene C-70 molecules inside the mesopore channels of SBA-15 silica as a hard template with the help of chlorinated aromatics, wherein the solubility of fullerenes is high, is reported. It is demonstrated that these metal-free mesoporous fullerene C-70 framework with a high surface area and bimodal pores with multifunctionality exhibit excellent performance in the oxygen reduction reaction for fuel cells and supercapacitors. This simple strategy can also be extended to other fullerene nanostructures with different carbon atoms which can exhibit interesting physicochemical properties and find applications in catalysis and energy storage

Direct synthesis and characterization of highly ordered cobalt substituted KIT-5 with 3D nanocages for cyclohexene epoxidation

Highly ordered cobalt incorporated KIT-5 silica (Co-KIT-5) with different Co contents and a well-ordered three-dimensional cage type porous structure were prepared for the first time by using Pluronic F127 as structure directing agent at different molar water to hydrochloric acid (nHO/) ratio. The amount of Co content in the silica framework of KIT-5 can be finely controlled with a simple adjustment of the nHO/ ratio as it controls the concentration of the H ions in the synthesis gel. It has been found that the nHO/ ratio of 463 is the best condition to obtain Co-KIT-5 with a high Co content. The obtained materials were characterized by various techniques such as powder X-ray diffraction (XRD), N adsorption studies, field emission high resolution scanning electron microscopy (FE-HRSEM), high resolution transmission electron microscopy (HRTEM), ultraviolet-visible diffused reflectance (UV-Vis DRS), electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS). Characterization results revealed that Co atom can be introduced in the silica framework without affecting the structural order and the textural parameters of the samples. ESR, XPS and UV-Vis DR spectra confirmed that the Co atoms are indeed occupy the tetrahedral coordination with the silica framework of KIT-5. The catalytic performance of Co-KIT-5 with different Co contents in the cyclohexene epoxidation has been investigated using TBHP/HO as oxidants and acetonitrile as a solvent. Co-KIT-5 exhibited a high catalytic performance with TBHP as oxidant and remained inactive when HO was used. The effect of various reaction parameters such as reaction time, reaction temperature, and reactant feed ratio and oxidant, affecting the catalytic activity of Co-KIT-5 has also been studied. Among the catalysts studied, Co-KIT-5-0.90 was found to be the best catalyst, affording a high conversion of cyclohexene. In addition, the catalyst was found to be highly stable and can be reused several times without affecting its catalytic activity under the optimized reaction conditions

Highly ordered iron oxide-mesoporous fullerene nanocomposites for oxygen reduction reaction and supercapacitor applications

In this study, we report a facile synthetic strategy to embed ultra-small iron oxide nanoparticles within the channels of highly ordered mesoporous fullerene (C-60) (Fe-MFC60-T, where T denotes the temperature of the template synthesis). The present work is judicially designed to form the hematite phase of iron oxide (alpha-Fe2O3) nanoparticles (NPs) through the subsequent calcination of Fe-MFC60-T. The Fe-MFC60-T materials were analysed comprehensively for obtaining their physico-chemical properties. Among the materials studied, Fe-MFC60-150 exhibits a unique doughnut-shaped morphology with a high specific surface area ( 598 m(2) g(-1)), crystalline wall structure, and well-ordered porosity. The Fe-MFC60-150 displays an adequate oxygen reduction reaction (ORR) activity with a positive onset potential at 0.85 V (vs RHE) and half wave potential at 0.78 V (vs RHE), low Tafel slope (66 mV per decade), high exchange current density (1.2 x 10(-10) A cm(-2)), and good tolerance towards methanol crossover. We also demonstrate that Fe-MFC60-150 is capable of delivering a specific capacitance of 112.4 F g(-1) at 0.1 A g(-1). The electrochemical performance of Fe-MFC60-150 towards ORR and super capacitor can be ascribed to the synergistic coupling effects between the active sites of alpha-Fe2O3 and MFC60