AI Article Synopsis
- Zeolites are crystalline materials made of silica and alumina that have unique properties, making them useful in industries as catalysts, adsorbents, and ion-exchangers.
- The performance of zeolites is significantly influenced by their silicon-to-aluminum (Si/Al) ratios and the arrangement of aluminum within their structure.
- The review covers methods for adjusting these ratios and distributions, various characterization techniques to analyze them, and discusses their effects on zeolite performance, along with future challenges in refining their properties.
Article Abstract
Zeolites are typically a class of crystalline microporous aluminosilicates that are constructed by SiO and AlO tetrahedra. Because of their unique porous structures, strong Brönsted acidity, molecular-level shape selectivity, exchangeable cations, and high thermal/hydrothermal stability, zeolites are widely used as catalysts, adsorbents, and ion-exchangers in industry. The activity, selectivity, and stability/durability of zeolites in applications are closely related to their Si/Al ratios and Al distributions in the framework. In this review, we discussed the basic principles and the state-of-the-art methodologies for regulating the Si/Al ratios and Al distributions of zeolites, including seed-assisted recipe modification, interzeolite transformation, fluoride media, and usage of organic structure-directing agents (OSDAs), The conventional and newly developed characterization methods for determining the Si/Al ratios and Al distributions were summarized, which include X-ray fluorescence spectroscopy (XRF), solid state Si/Al magic-angle-spinning nuclear magnetic resonance spectroscopy (Si/Al MAS NMR), Fourier-transform infrared spectroscopy (FT-IR), The impact of Si/Al ratios and Al distributions on the catalysis, adsorption/separation, and ion-exchange performance of zeolites were subsequently demonstrated. Finally, we presented a perspective on the precise control of the Si/Al ratios and Al distributions of zeolites and the corresponding challenges.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9945477 | PMC |
| http://dx.doi.org/10.1039/d2sc06010h | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exploring a Novel Adsorbent for CO Capture and Gas Separation.
ACS Appl Mater Interfaces
January 2025
Université de Caen Normandie, ENSICAEN, CNRS, LCS, Laboratoire Catalyse et Spectrochimie, Caen 14000, France.
The urgent need to mitigate carbon emissions has spurred research into small-pore zeolites as cost-effective options for CO capture by solid adsorbents, particularly in postcombustion and biogas separation applications. In this study we investigate levyne (LEV-type) zeolite, a largely unexplored material for CO adsorption, as a novel adsorbent for CO capture and gas separation. Using seed-assisted synthesis approaches and different synthesis conditions, nanosized and micron-sized LEV zeolites were synthesized and characterized in terms of synthesis pathways, morphology, crystal size, and chemical composition.
View Article and Find Full Text PDFAdsorption of Eu and Gd on high-charge micas as inner-sphere complexes.
J Colloid Interface Sci
January 2025
Departamento QUIPRE, Universidad de Cantabria, Avda. Los Castros 46 39005 Santander, Spain; Grupo de Nanomedicina, IDIVAL, Avda. Cardenal Herrera Oria s/n, 39011 Santander, Spain. Electronic address:
High-charge micas exhibit improved adsorption properties and are a promising alternative clay material for the engineered barrier in deep geological repositories. When combined with Eu cations, they serve as an in situ luminescent probe for tracking the physical-chemical changes occurring in this engineered barrier over the long term. Therefore, a better understanding of the local environment of the lanthanide is highly desirable to comprehend the specific behavior of these systems.
View Article and Find Full Text PDFFrom 2D kaolinite to 3D amorphous cement.
Sci Rep
January 2025
Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117546, Singapore.
Kaolinite is a single 2D layer of kaolin or metakaolin (MK), common clays that can be characterized as layered 3D materials. We show that because of its chemical composition, kaolinite can be converted into an amorphous 3D material by chemical means. This dimensional transformation is possible due to the large surface to volume ratio and chemical reactivity of kaolinite.
View Article and Find Full Text PDFMechanical properties and mechanisms of soda residue and fly ash stabilized soil.
Sci Rep
January 2025
School of Civil and Ocean Engineering, Jiangsu Ocean University, Jiangsu, 222005, China.
To improve the utilization rates of soda residue (SR) and fly ash (FA), reduce environmental pollution, and enhance the mechanical properties of marine clay (MC), this study proposes mixing SR, FA, and MC with cement and /or lime to prepare soda residue-fly ash stabilized soil (SRFSS). Using an orthogonal design for the proportions, the study analyzes the compaction performance, unconfined compressive strength (UCS), and shear strength of SRFSS. The influence of various factors on the mechanical properties of SRFSS was investigated through range and variance analyses.
View Article and Find Full Text PDFAntimicrobial and Oxidative Activities of Different Levels of Silver-Exchanged Zeolites X and ZSM-5 and Their Ecotoxicity.
Pharmaceuticals (Basel)
November 2024
Faculty of Physics, Sofia University "St. Kliment Ohridski", 5 James Bourchier Blvd, 1164 Sofia, Bulgaria.
Objectives: The antimicrobial, oxidative activities, and ecotoxicity of synthesized silver-loaded zeolites (X and ZSM-5(MFI), Si-to-Al ratios 12 and 25) were studied, linking antimicrobial properties to material structure and released active silver species.
Methods: The materials were characterized by SEM, EDX, TEM, and XRPD. All materials, with a silver content of 1-3%wt for the Ss and about 35%wt for the X-zeolites, were tested against and .
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!