Sulfonic-based precursors (SAPs) for silica mesostructures: Advances in synthesis and applications

Sulfonic acid-based precursors (SAP) play an important role in tailoring mesoporous silica’s and convert them to a solid acid catalyst with a Bronsted-type nature. These kinds of solid acids contribute to sustainable and green chemistry by their heterogeneous, recyclable, and high efficiency features. Therefore, knowing the properties and reactivity of SAPs can guide us to manufacture a sulfonated mesostructures compatible with reaction type and conditions. In the present review, some of the important SAPs, their reactivity and mechanism of functionalization are discussed

Silica-Supported Co3O4 Nanoparticles as a Recyclable Catalyst for Rapid Degradation of Azodye

In this paper, silica nanoparticles with particle size of ~ 10-20 nm were selected as a support for the synthesis of Co3O4 nanoparticles by impregnation of silica nanoparticles in solution of Co(II) in a specific concentrations and then calcination to 800 oC. This nanocomposite was then, used as a catalyst for oxidative degradation of methyl orange (MO) with ammonium persulfate in aqueous media. Effect of pH, temperature, contact time, amount of oxidant and catalyst were studied in the presence of manuscript. Scanning electron microscope (SEM), electron dispersive spectroscopy (EDS), FT-IR, and ICP-AES analyses were used for analysis of silica-supported Co3O4 (Co3O4/SiO2). Treating MO with ammonium persulfate in the presence of Co3O4/SiO2 led to complete degradation of MO under the optimized conditions. Also, the catalyst exhibited recyclability at least over 10 consecutive runs.

In silico Investigation on the Inhibiting Role of Nicotine/Caffeine by Blocking the S Protein of SARS-CoV-2 Versus ACE2 Receptor

In this paper, we studied the in silico interaction of angiotensin-converting enzyme 2 (ACE2) human receptor with two bioactive compounds, i.e., nicotine and caffeine, via molecular dynamic (MD) simulations. The simulations reveal the efficient blocking of ACE2 by caffeine and nicotine in the exposure to the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have selected the two most important active sites of ACE2-S protein, i.e., 6LZG and 6VW1, which are critically responsible in the interaction of S protein to the receptor and thus, we investigated their interaction with nicotine and caffeine through MD simulations. Caffeine and nicotine are interesting structures for interactions because of their similar structure to the candidate antiviral drugs. Our results reveal that caffeine or nicotine in a specific molar ratio to 6LZG shows a very strong interaction and indicate that caffeine is more efficient in the interaction with 6LZG and further blocking of this site against S protein binding. Further, we investigated the interaction of ACE2 receptor- S protein with nicotine or caffeine when mixed with candidate or approved antiviral drugs for SARS-CoV-2 therapy. Our MD simulations suggest that the combination of caffeine with ribavirin shows a stronger interaction with 6VW1, while in case of favipiravir+nicotine, 6LZG shows potent efficacy of these interaction, proposing the potent efficacy of these combinations for blocking ACE2 receptor against SARS-CoV-2

The Isocyanurate-Carbamate-Bridged Hybrid Mesoporous Organosilica: An Exceptional Anchor for Pd Nanoparticles and a Unique Catalyst for Nitroaromatics Reduction

Hybridisation of mesoporous organosilicas (MO) to reinforce the surface capability in adsorption and stabilisation of noble metal nanoparticles is of great attention in generating/supporting noble metal within their matrices and transforming them into efficient heterogeneous catalysts. Here, we used a unique hybrid of organic-inorganic mesoporous silica in which pore profile pattern was similar to the well-known mesoporous silica, SBA-15 for catalysis. This hybrid mesoporous organosilica was further engaged as a support in the synthesis and stabilisation of Pd nanoparticles on its surface, and then, the obtained Pd-supported MO was employed as a heterogeneous green catalyst in the conversion of aqueous p-nitrophenol (PNP) to p-aminophenol (PAP) at room temperature with efficient recyclability

Silica-Supported Co3O4 Nanoparticles as a Recyclable Catalyst for Rapid Degradation of Azodye

In this paper, silica nanoparticles with particle size of ~ 10-20 nm were selected as a support for the synthesis of Co3O4 nanoparticles by impregnation of silica nanoparticles in solution of Co(II) in a specific concentrations and then calcination to 800 oC. This nanocomposite was then, used as a catalyst for oxidative degradation of methyl orange (MO) with ammonium persulfate in aqueous media. Effect of pH, temperature, contact time, amount of oxidant and catalyst were studied in the presence of manuscript. Scanning electron microscope (SEM), electron dispersive spectroscopy (EDS), FT-IR, and ICP-AES analyses were used for analysis of silica-supported Co3O4 (Co3O4/SiO2). Treating MO with ammonium persulfate in the presence of Co3O4/SiO2 led to complete degradation of MO under the optimized conditions. Also, the catalyst exhibited recyclability at least over 10 consecutive runs. Copyright © 2016 BCREC GROUP. All rights reserved Received: 12nd December 2015; Revised: 27th January 2016; Accepted: 27th January 2016 How to Cite: Baghban, A., Doustkhah, E., Rostamnia, S., Aghbash, K.O. (2016). Silica-Supported Co3O4 Nanoparticles as a Recyclable Catalyst for Rapid Degradation of Azodye. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3): 284-291 (doi:10.9767/bcrec.11.3.568.284-291) Permalink/DOI: http://doi.org/10.9767/bcrec.11.3.568.284-29

Exfoliated graphene-based 2d materials: Synthesis and catalytic behaviors

Because graphene-based materials have a high surface area in interlayer space, there is a high tendency toward elimination of interlayer interactions through several methods. There are three distinct path-ways to overcome the interlayer interaction: intercalation, pillaration, and exfoliation. In exfoliation, there is the least interaction between the layers. By increasing exfoliation strength, we can tune and increase the catalytic activity. In this book chapter, we will study the effect of interface and interlayer interactions on the catalytic feature of graphene-based materials. Furthermore, we will show how we can exfoliate graphene (oxide) and how it is working in the catalysis of an organic transformation. Also, we will discuss and compare the catalytic activity coming from pillaration and exfoliation

Pd Thickness Optimization on Silicate Sheets for Improving Catalytic Activity

Abstract Maximizing surface‐to‐body ratio demands ever smaller metallic palladium (Pd) nanoparticles for catalytic applications. The quest for miniaturization is now reaching the single‐atom limit. However, if the supported Pd is below a critical size, the Pd hybridization with the supporting material can detrimentally reduce the labile electrons that facilitate the catalytic reactions. Thus, the smallest attainable size, i.e., single‐atom Pd, may not offer the best efficiency. Here, it is demonstrated that Pd with at least six atomic layers (or thickness of ≈1 nm) on the silicate sheets, synthesized via the partial exfoliation of a layered silicate, exhibits a metallic‐like electronic property, yielding an excellent catalytic activity (e.g., turnover frequency) for dehydrogenating formic acid higher than both isotropic Pd nanoparticles and single‐atom Pd

Tandem aldol condensation-Diels–Alder-aromatization sequence of reactions: a new pathway for the synthesis of 2-tetralone derivatives

A series of new polysubstituted derivatives of 2-tetralones possessing two ester groups were synthesized via a tandem aldol condensation-Dielsâ Alder-aromatization sequence of reactions. All the three steps took place in one pot and in the presence of aminofunctionalized silica coated Fe3O4 nanoparticles as the catalyst. In situ formed dienes reacted with diethyl acetylenedicarboxylate at room temperature and the process was followed by spontaneous aromatization of the cycloadducts to produce high yields of the final tetralone products. Further studies suggest that the process goes through an initial aldol condensation-cycloaddition sequence followed by oxidation and rearrangement steps. After completion of the reactions, the catalyst could be recycled and reused efficiently in next reactions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author