Silica aerogel-supported copper catalyst prepared via ambient pressure drying process

Amiri, Taher Yousefi; Moghaddas, Jafarsadegh; Khajeh, S.

doi:10.1007/s10971-015-3892-0

Cited by 15 publications

(1 citation statement)

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“…Silica aerogels are a unique class of highly porous materials (80-99.8%) with large specific surface area (500-1200 m 2 •g −1 ), low thermal conductivity (0.004-0.03 W•m −1 •K −1 ), low density (0.003-0.5 g•cm −3 ), low refraction index (~1.05), and low dielectric constant (1.0-2.0) [1][2][3][4][5][6]. Due to their remarkable properties, silica aerogels have become an object of widespread interest in many branches of industry over the past few years, with particular interest in acoustic barriers [7], adsorbents (for oil and organic liquids) [8], sensors [9], catalyst supports [10], and drug delivery systems [11] or aeronautic and astronautic applications [12,13]. Moreover, silica aerogels (even thin layers) are excellent insulating materials compared to traditional insulations, e.g., mineral wool.…”

Section: Introductionmentioning

confidence: 99%

Effect of Drying Control Agent on Physicochemical and Thermal Properties of Silica Aerogel Derived via Ambient Pressure Drying Process

Pawlik,

Szpikowska-Sroka,

Miros

et al. 2023

Energies

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This paper presents the effect of drying control agents on the physicochemical and thermal properties of hydrophobic silica aerogels derived via the ambient pressure drying (APD) method by a surface silylation using a TMCS/n-hexane mixture. The structural and physicochemical properties of synthesized DMF-modified and unmodified hydrophobic silica aerogels were characterized using Brunauer–Emmett–Teller (BET) analysis, thermo-gravimetric analysis, FT-IR, and Raman spectroscopic techniques. Based on the obtained results, the differences in structure between samples before and after a surface silylation and the effect of drying control agents were documented. The structural measurements confirmed the efficient silylation process (TMCS/n-hexane), as well as the presence of DMF residues of hydrogen bonded with unreacted Si-OH silanol groups within the silica backbone after surface modification. Based on TG analysis, it was found that DMF addition improves thermal resistance (up to 320 °C) and hydrophobic character of prepared aerogel. Modification of the silica aerogel synthesis process by DMF also resulted in a significant increase in BET—the specific surface area, for the unmodified aerogel was ~828 m2/g, and for the DMF-modified aerogel more than 1200 m2/g—much higher than the value of silica aerogels available on the market.

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Section: Introductionmentioning

confidence: 99%

Effect of Drying Control Agent on Physicochemical and Thermal Properties of Silica Aerogel Derived via Ambient Pressure Drying Process

Pawlik,

Szpikowska-Sroka,

Miros

et al. 2023

Energies

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Highly Active and Efficient Cu@SiO₂ Catalyst: Enabled Nucleophilic and Electrophilic Activation of Active Methylene Compounds

2022

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The utility of copper is strikingly afforded due to the variable oxidation state being widely used in various organic reactions. The copper-catalyzed CÀ C bond formation with active methylene compounds are a straightforward approach with widespread uses in synthetic organic chemistry. A significantly lower amount of Cu-supported SiO 2 catalyst was synthesized through sol-gel method. The microscopy analysis reveals the formation of spherical morphology and the uniform distribution of Cu nanoparticles of 2.5 nm size. Furthermore, copper was found in Cu + 2 state by XPS analysis. The NH 3 -TPD analysis estimated the 0.092 mmol/g acidic sites. The synthesized multifunctional catalyst was used for gabapentin intermediates through a series of active methylene compounds through tandem organic reactions. The catalyst gave excellent conversion (99%) and selectivity (99%) of the desired product. The catalyst was found to be highly stable and recycled for six cycles without losing any activity and selectivity to the reaction product.

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Porous SiO₂ supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate

Guo

Tian

et al. 2021

Applied Organom Chemis

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Reducing the thermal decomposition temperature of ammonium perchlorate (AP) is of great significance for its application in composite solid propellants. Here, CuO/SiO 2 nanocomposites were prepared using wet impregnation method with Cu (CH 3 COO) 2 ÁH 2 O as copper precursor followed by a calcination process. The structure and morphology of the prepared samples were characterized with the help of scanning electron microscopy (SEM), Xray diffraction (XRD), and Brunauer-Emmett-Teller (BET), respectively. The outcomes revealed the uniform dispersion of CuO were throughout silica aerogels to prevent agglomeration efficiently. Moreover, results from differential scanning calorimeter (DSC) showed that CuO/SiO 2 nanocomposites could effectively enhance AP's thermal decomposition since they have large specific surface areas, many active reduction sites, and good adsorption capacity. As expected, the high decomposition temperature of AP was reduced from 418.7 C to 341.8 C when the amount of CuO/SiO 2 nanocomposites was 4 wt%. Therefore, silica aerogels were good catalyst supports of CuO for AP's thermal decomposition. It can bring about new potential for application of new materials in high energy as AP-based catalysts propellants which are solid in nature. K E Y W O R D Sammonium perchlorate, CuO/SiO 2 nanocomposites, silica aerogels, the thermal decomposition

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Silica aerogel-supported copper catalyst prepared via ambient pressure drying process

Cited by 15 publications

References 50 publications

Effect of Drying Control Agent on Physicochemical and Thermal Properties of Silica Aerogel Derived via Ambient Pressure Drying Process

Effect of Drying Control Agent on Physicochemical and Thermal Properties of Silica Aerogel Derived via Ambient Pressure Drying Process

Highly Active and Efficient Cu@SiO₂ Catalyst: Enabled Nucleophilic and Electrophilic Activation of Active Methylene Compounds

Porous SiO₂ supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate

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Silica aerogel-supported copper catalyst prepared via ambient pressure drying process

Cited by 15 publications

References 50 publications

Effect of Drying Control Agent on Physicochemical and Thermal Properties of Silica Aerogel Derived via Ambient Pressure Drying Process

Effect of Drying Control Agent on Physicochemical and Thermal Properties of Silica Aerogel Derived via Ambient Pressure Drying Process

Highly Active and Efficient Cu@SiO2 Catalyst: Enabled Nucleophilic and Electrophilic Activation of Active Methylene Compounds

Porous SiO2 supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate

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Product

Resources

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Highly Active and Efficient Cu@SiO₂ Catalyst: Enabled Nucleophilic and Electrophilic Activation of Active Methylene Compounds

Porous SiO₂ supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate