Vapor phase aldol condensation over fully ion-exchanged montmorillonite-rich catalysts

Azzouz, Abdelkrim; Messad, D.; Nistor, Ileana Denisa; Catrinescu, Cezar; Zvolinschi, Anita; Asaftei, Simona

doi:10.1016/s0926-860x(02)00524-0

Cited by 46 publications

(36 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The surface basicity and hydrophilic character were assessed via thermal programmed desorption measurements (TPD) in a tubular glass reactor [31][32][33]. The later was coupled to a Li-840A dual CO 2 /H 2 O Gas Analyzer.…”

Section: Gas Adsorption and Desorption Testsmentioning

confidence: 99%

Properties of SBA-15 modified by iron nanoparticles as potential hydrogen adsorbents and sensors

Ouargli

Nousir

Slama

et al. 2015

Journal of Physics and Chemistry of Solids

View full text Add to dashboard Cite

Section: Gas Adsorption and Desorption Testsmentioning

confidence: 99%

Properties of SBA-15 modified by iron nanoparticles as potential hydrogen adsorbents and sensors

Ouargli

Nousir

Slama

et al. 2015

Journal of Physics and Chemistry of Solids

View full text Add to dashboard Cite

“…The clay catalysts were prepared by thorough purification using an optimized procedure fully described elsewhere [23]. This procedure includes repeated settlings, controlled calcinations (loss on calcinations of ca.…”

Section: Catalyst Preparationmentioning

confidence: 99%

“…ozone] mixture throughput = 5 mg min -1 ; Catalyst amount = 1 g of dry ion-exchanged montmorillonite; Initial concentration of oxalic acid = 2.5 9 10 -3 M, Reaction mixture volume = 500 mL; T = 298 K lower ozonation. A possible explanation is that excessively acidic surfaces may hinder adsorption of oxalic acid, by attenuating or shading the base character of the oxygen atoms surrounding the exchangeable cation that act as adsorption sites [23].…”

Section: Effect Of the Surface Aciditymentioning

confidence: 99%

Ozonation of oxalic acid catalyzed by ion-exchanged montmorillonite in moderately acidic media

Azzouz

Kotbi

Niquette

et al. 2010

Reac Kinet Mech Cat

View full text Add to dashboard Cite

Ion-exchanged montmorillonite-rich materials (ca. 96% purity) like NaMt, Fe(II)Mt, Co(II)Mt, Ni(II)Mt and Cu(II)Mt showed catalytic activity in the ozonation of oxalic acid in water at room temperature, in the pH range 3.4-6.0. The conversion of oxalic acid exceeds 95% after 180 min of ozone bubbling in the presence of Fe(II)Mt. The oxalic acid removal efficiency was found to increase swiftly with the acid character of the clay surface up to a certain level, but decreases gently with excessive surface acidity. The pH exerts a strong influence on the catalyst efficiency, because it induces changes in the composition of both the liquid media and catalyst. The synergic action of ozone and clay catalysts at acidic pH seems to involve ozone adsorption and interaction between cation and adsorbed oxalate. The negative effect of increasing pH between 3.44 and 6.0 is discussed in terms of a decrease in the amount and mobility of the cation in the vicinity of the clay surface, and of a decay in the clay surface area available to ozonation.

show abstract

“…This was achieved according to a procedure fully described elsewhere. 46,47 Measurements were achieved using organo-Mts in the powder The retention capacity of CO 2 (CRC) and water (WRC) was assessed for all adsorbents by thermal programmed desorption of carbon dioxide (CO 2 -TPD) according to a procedure fully described elsewhere. 46,47 Results and discussion…”

Section: Thermal Desorption Measurementsmentioning

confidence: 99%

Improved carbon dioxide storage over clay-supported perhydroxylated glucodendrimer

et al. 2017

View full text Add to dashboard Cite

Low-cost biosourced hybrid microporous adsorbents with improved affinity towards carbon dioxyde (CO2) were prepared through the incorporation of various amounts of glucosylated dendrimer into bentonite- and montmorillonite-rich composite materials. Characterization by nitrogen adsorption–desorption isotherms, surface specific and pore size analyses (BET and BJH), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) revealed changes in the interlayer spacing and textural structure of the materials. Thermal programmed desorption measurements (TPD) showed significant improvements of the retention capacity of CO2 (CRC) and water (WRC). This was explained in terms of enhancement of both surface basicity and hydrophilic character due to the incorporation of terminal polyhydroxyl groups. The CRC was found to vary according to the previous saturation time with CO2 and the carrier gas throughput. CO2 was totally released upon temperature not exceeding 80 °C or even at room temperature upon strong carrier gas stream, thus providing evidence that CO2 capture involves almost exclusively physical interaction with the OH groups of the dendrimer. This result opens promising prospects for the reversible capture of carbon dioxide with easy release without thermal regeneration, more particularly when extending this concept to biosourced dendrimers.

show abstract

Vapor phase aldol condensation over fully ion-exchanged montmorillonite-rich catalysts

Cited by 46 publications

References 27 publications

Properties of SBA-15 modified by iron nanoparticles as potential hydrogen adsorbents and sensors

Properties of SBA-15 modified by iron nanoparticles as potential hydrogen adsorbents and sensors

Ozonation of oxalic acid catalyzed by ion-exchanged montmorillonite in moderately acidic media

Improved carbon dioxide storage over clay-supported perhydroxylated glucodendrimer

Contact Info

Product

Resources

About