Description of the preferential transport of monovalent salts through Na–mordenite membrane: Physico-chemical aspects

Limousy, Lionel; Dutournié, Patrick; Chevereau-Landais, E

doi:10.1016/j.micromeso.2012.01.025

Cited by 6 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pt@H-ZSM-5 has a BAS density of 204 μmol g –1 , due to the complete replacement of Na + with protons. The two bands at 1444 and 1595 cm –1 attributable to pyridine adsorbed on Na cations ,,− are absent for Pt@H-ZSM-5, confirming the complete ion exchange of Na + with H + . A band centered at 1454 cm –1 assigned to pyridine bound on Lewis acid sites (LAS) appears in the spectrum of Pt@H-ZSM-5 (Figure a). − ,, Two types of Al-based LAS exist in zeolites: i.e., extraframework Al (Al EF ) LAS and framework Al (Al FR ) LAS. , 27 Al MAS NMR spectra reveal that the majority of Al atoms are incorporated into the zeolite framework, as evidenced by a strong band at 50–60 ppm (Figure b). , Two 27 Al resonance bands at ∼0 and ∼30 ppm, attributable to octacoordinated Al EF LAS and pentacoordinated Al EF LAS, respectively, , are barely above the detection limit in the spectra.…”

Section: Resultsmentioning

confidence: 78%

Selectivity Control in Tandem Catalytic Furfural Upgrading on Zeolite-Encapsulated Pt Nanoparticles through Site and Solvent Engineering

Cho

Kim

2020

ACS Catal.

View full text Add to dashboard Cite

Selectivity control is a pressing challenge in developing selective tandem catalytic processes. In this work, we demonstrate that tailoring types of acid sites of zeolite-encapsulated Pt nanoparticles (NPs) and choosing solvents provide a compelling strategy to manipulate product distribution in tandem catalysis. The model tandem furfural conversion with acetone and ethanol (EtOH) is investigated in cyclohexane and EtOH solvents. Pt NPs encapsulated in ZSM-5 with Brønsted acid sites (BAS) only located in intracrystalline mesopores selectively mediate the tandem aldol condensation and subsequent hydrogenation of furfural and acetone by limiting the access of furfural to Pt sites and promoting the aldol condensation. A combined yield of 69% toward hydrogenated aldol adducts is achieved. In contrast, furfural hydrogenation to valeric acid (VA) and ethyl valerate (EV) dominates with a combined yield of 80% on Pt NPs encapsulated in ZSM-5 with Lewis acid sites (LAS) and BAS in both zeolitic micropores and intracrystalline mesopores. The concentration of EtOH in the reaction system is identified as another key parameter in selectivity control: (1) low EtOH concentrations (EtOH to furfural ratio of <5) suppress the catalytic transfer hydrogenation pathway and favor the formation of 2methylfuran (MF) from furfural, as most hydrogenation and hydrogenolysis steps occur on Pt NPs, (2) modest EtOH concentrations (EtOH to furfural ratio of 5−10) favor VA/EV by enabling the catalytic transfer hydrogenation pathway in zeolitic micropores and exposing intermediates to BAS prior to Pt NPs, and (3) high EtOH concentrations (EtOH to furfural ratio of >10) suppress the production of VA/EV by excessive water formation via acid-catalyzed etherification of EtOH. Therefore, tailoring the nature of active sites and changing the solvent composition are both effective strategies in manipulating the product distribution in tandem catalysis.

show abstract

Section: Resultsmentioning

confidence: 78%

Selectivity Control in Tandem Catalytic Furfural Upgrading on Zeolite-Encapsulated Pt Nanoparticles through Site and Solvent Engineering

Cho

Kim

2020

ACS Catal.

View full text Add to dashboard Cite

show abstract

“…Membrane processes, low cut-off ultrafiltration and nanofiltration, are effective separation techniques at low-consumption, and avoid or limit the resort to chemical treatments [31,32].…”

Section: -Introductionmentioning

confidence: 99%

Synthesis of mono- and bi-layer MFI zeolite films on macroporous alumina tubular supports: Application to nanofiltration

Said

Limousy

Nouali

et al. 2015

Journal of Crystal Growth

View full text Add to dashboard Cite

“…Na-mordenite was then produced by seeded hydrothermal synthesis at 155°C for 42 h in an autoclave. The elemental composition of the Na-mordenite is Na 8 Al 8 Si 40 O 96 nH 2 O (Limousy et al 2013).…”

Section: Mordenite Synthesis and Copper Exchange Protocolsmentioning

confidence: 99%

Study of the antimicrobial and antifouling properties of different oxide surfaces

Blel

Limousy

Dutournié

et al. 2016

Environ Sci Pollut Res

Self Cite

View full text Add to dashboard Cite

Membrane separation processes find applications in an array of fields as they use far less energy and chemical agents than competing processes. However, a major drawback of membrane technology is that biofilm formation alters membrane performances. Preventing biofilm formation is thus a pivotal challenge for larger-scale development of membrane processes. Here, we studied the comparative antibacterial activities of different inorganic membranes (ceramic and zeolite-coated ceramic with or without copper exchange) using several bacterial strains (Escherichia coli, Staphylococcus aureus, and Bacillus subtilis). In static conditions, alumina plates coated with Cu-exchanged zeolite showed significant bactericidal activity. In dynamic mode (circulation of a contaminated nutrient medium), there was no observable bacterial adhesion at the surface of the Cu-exchanged material. These results confirm the antifouling properties of the Cu-mordenite layer due to both the increased hydrophilicity and antibacterial properties of the active layer.Tests performed with tubular filtration membranes (without copper exchange) showed a significant decline in membrane hydraulic properties during filtration of culture media containing bacteria, whereas copper-exchanged membranes showed no decline in hydraulic permeability. Filtration tests performed with concentrated culture media containing spores of B. subtilis led to a significant decrease in membrane hydraulic permeabilities (but less so with Cu-exchanged membranes). The surfaces showed less effective global antifouling properties during the filtration of a concentrated culture medium due to competition between bacterial growth and the bactericidal effect of copper. Analyses of copper leached in solution show that after a conditioning step, the amount of copper released is negligible.

show abstract

Description of the preferential transport of monovalent salts through Na–mordenite membrane: Physico-chemical aspects

Cited by 6 publications

References 19 publications

Selectivity Control in Tandem Catalytic Furfural Upgrading on Zeolite-Encapsulated Pt Nanoparticles through Site and Solvent Engineering

Selectivity Control in Tandem Catalytic Furfural Upgrading on Zeolite-Encapsulated Pt Nanoparticles through Site and Solvent Engineering

Synthesis of mono- and bi-layer MFI zeolite films on macroporous alumina tubular supports: Application to nanofiltration

Study of the antimicrobial and antifouling properties of different oxide surfaces

Contact Info

Product

Resources

About