Zeolites and related crystalline molecular sieves are utilised in a wide range of reactions and processes due to their regular microporous structure, strong acidity, shape selectivity and ion-exchange properties. However, their practical applications can be limited by the small size of the channels and cavities of the microporous structures, and therefore, a great deal of effort has been devoted to enhancing the transport of large-sized molecules in the host pores. Several commercially available zeolites, including faujasite (FAU), mordenite (MOR), beta (BEA), ZSM-5 (MFI) and zeolite L (LTL), have been exposed to a variety of acid and base treatments in the presence of a surfactant (cetyltrimethyl ammonium bromide, CTAB), which led to the controlled introduction of intracrystalline mesoporosity. The detailed characterisation of the obtained mesostructured zeolites has been carried out using FTIR spectroscopy, high resolution TEM, XRD, N2 adsorption, 29Si and 27Al MAS NMR. This work demonstrates a successful application of the supramolecular templating approach for generating tuneable mesoporosity in a range of zeolites possessing 12-membered ring channels, which has been applied to zeolite L for the first time, thus producing hierarchical meso-microporous materials with improved accessibility of active sites and enhanced catalytic performance in dealkylation of tri-isopropylbenzene.

/pdf/synthesis-of-nanostructured-catalysts-by-surfactant-20jf5rdcgg.pdf

Synthesis of nanostructured catalysts by surfactant-templating of large-pore zeolites

Effects of the zeolite concentration on the microstructure of high internal phase emulsions stabilized by surfactant-coated zeolite particles

Getting the Most out of Parahydrogen-Induced Signal Enhancement for MRI of Reacting Heterogeneous Systems

Electrochemical analysis provides a convenient way to screen active materials for thermocatalytic processes involving implicit electrochemical redox mechanisms. Here, we show how a combinatorial method based on scanning electrochemical microscopy (SECM) rapidly screens multiple catalysts for hydrogen peroxide direct synthesis reaction by independently analyzing their hydrogen oxidation and oxygen reduction reactivities on the same chip. We present a reproducible and quantifiable procedure to fabricate catalyst spot array samples using photolithography and microdispensing. This procedure enables the exploration of up to 10 catalysts with three replicates each on one chip, allowing us to study 30 compositions to identify reactive trends in a vast compositional space. SECM imaging with linear sweep voltammetry improved the accuracy and efficiency of data collection. Kinetic parameters of both half-reactions for each catalyst were extracted from experimental data with the help of established analytical theory and finite element analysis simulation. A library of AuxPty catalysts with a range of Au/Pt ratios from 1200:1 to 120:12 were examined. For the synthesized AuxPty catalysts, the rate constants of oxygen reduction and hydrogen reduction increase as Pt content increases and then level off beyond Au120Pt7. Therefore, to achieve the highest activity while keeping the cost low, Au120Pt7 would be a promising composition to further investigate. We believe this SECM-based technique will expedite the catalyst design and discovery process for classes of thermochemical reactions involving underlying heterolytic electrochemical mechanisms, thus assisting in the synthesis and utilization of sustainable fuels and commodity chemicals. 

Electrochemical Screening of Au/Pt Catalysts for the Thermocatalytic Synthesis of Hydrogen Peroxide Based on Their Oxygen Reduction and Hydrogen Oxidation Activities Probed via Voltammetric Scanning Electrochemical Microscopy

A method of producing a hierarchical zeolite composite catalyst is provided. The method includes dissolving, in an alkaline solution and in the presence of a surfactant, a catalyst precursor comprising mesoporous zeolite to yield a dissolved zeolite solution, where the mesoporous zeolite comprises large pore ZSM-12 and medium pore ZSM-5. The method also includes condensing the dissolved zeolite solution to yield a solid zeolite composite from the dissolved zeolite solution and heating the solid zeolite composite to remove the surfactant. The method further includes impregnating the solid zeolite composite with one or more active metals selected from the group consisting of platinum, rhenium, rhodium, molybdenum, nickel, tungsten, chromium, ruthenium, gold, and combinations thereof to yield impregnated solid zeolite composite and calcining the impregnated solid zeolite composite to produce the hierarchical zeolite composite catalyst. The hierarchical zeolite composite catalyst has a mesostructure comprising at least one disordered mesophase and at least one ordered mesophase.

Composite hierarchical zeolite catalyst for heavy reformate conversion to xylenes

n-Hexadecane hydroconversion has been investigated in a series of bifunctionnal metal/acid catalysts featuring distinct well-defined pore architectures. The acidic components were prepared from dealuminated Y zeolites with Si/Al of 15 and 30 post treated in alkaline medium to generate ordered or non-ordered secondary networks of mesopores and from aluminated ordered mesoporous materials MCM-41, MCM-48, KIT-6 type materials and amorphous silica gel. Activity relates linearly to the strength and number of strong Bronsted acid sites, while selectivity, more precisely the yield in isomerization products, scales directly with the mesopore volume of the catalyst. The architecture of the mesoporous network, namely the ordering, interconnectivity, homogeneity of the mesopores, affects little catalytst behavior. Confrontation of catalytic data with diffusion measurements suggests the existence of an optimal mesopore size above which the number of strong Bronsted sites and the mesopore volume are the only parameters governing catalytic performance.

/pdf/impact-of-pore-architecture-on-the-hydroconversion-of-long-1dv1zmk8uz.pdf

Impact of Pore Architecture on the Hydroconversion of Long Chain Alkanes over Micro and Mesoporous Catalysts

A mesoporous zeolitic material possessing an ordered mono-dimensional (1D) or two-dimensional (2D) network of micropores (ie pores < 2nm in diameter) containing mesopores (pores with diameters in the range 2- 50 nm) connected to the microporores, the mesopores being characterized by an aspect ratio (length to width) higher than 2, a ratio of the volume of the intracrystalline mesopores to the volume of the micropores in the range 0.1 to 2 and an orientation of the mesopores in the direction of the micropores.

Mesoporous Zeolitic Material, Method for Making the Same and Use

A method to remove silica from a silica containing material characterized in that it comprises (i) contacting said silica containing material with a first metal ion carbonate, to obtain a first composition, and (ii) heating said first composition in a vessel at a temperature sufficient to increase the pressure above the atmospheric pressure in said vessel or at a pressure of at least 2 bara and at a temperature of at least 80°C, preferably 100°C wherein said pressure is preferably autogeneously generated, wherein the total amount of water of said first composition originating from (a) the silica containing material and from (b) the first metal ion carbonate is greater or equal to 4 mol of water per mol of metal ion carbonate, and wherein the first composition obtained at step (i) is not a suspension in water and is under solid state at standard temperature and pressure (STP), before the performance of step (ii) and wherein said silica containing material is a zeolite

Method for preparing a mesoporous material, material obtained thereof and use

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Laura Vaugon

Author Tools

Chat about Author

Papers

Impact of Pore Architecture on the Hydroconversion of Long Chain Alkanes over Micro and Mesoporous Catalysts

Mesoporous Zeolitic Material, Method for Making the Same and Use

Method for preparing a mesoporous material, material obtained thereof and use