Improvement of hydrothermal stability of zeolitic imidazolate frameworks

The metal-organic framework ZIF-8, which undergoes hydrolysis under hydrothermal conditions, is endowed with high water-resistance after a shell-ligand-exchange-reaction. The stabilized ZIF-8 retains its structural characteristics with improved application performances in adsorption and membrane separation. © 2013 The Royal Society of Chemistry

Hydrothermal synthesis of uniform and dense NaA zeolite membrane in the electric field

Uniform and dense NaA zeolite membranes were prepared on the tubular porous alpha-AI(2)O(3) supports in the electric field, where the charged zeolite particles attracted and transported to the support surface for membrane preparation homogeneously. The membranes properties were characterized by XRD, SEM and pervaporation for dehydration of 95 wt% isopropanol/water mixture at 343 K, respectively. The applied potential had great effect on membrane morphology, membrane thickness and separation performance. Under the action of the applied electric field, the negatively charged zeolite particles could migrate to the support surface homogenously and rapidly, facilitating to form uniform and dense membranes in a short time. Most zeolite particles transported to the support surface for membrane formation in the electric field, which increased the percentage of the product contained in the support surface and thus fully utilized the zeolite particles. High-quality NaA zeolite membrane, i.e., with a separation factor (water/isopropanol) of 3281 and a flux of 1.24 k g/(M-2 h), could be prepared with the electrical potential of 1.0 V. (C) 2006 Elsevier Inc. All rights reserved

Microwave synthesis of LTA zeolite membranes without seeding

A new method called "in-situ aging-microwave synthesis" was developed for zeolite membrane synthesis. High quality LTA zeolite membranes were successfully microwave-synthesized without seeding by this method. It was found that the formed zeolite layer was composed of sphere grains with undefined crystal facets. The necessity of in-situ aging was discussed. The effects of synthesis parameters including in-situ aging temperature, time and microwave heating time, on the characteristics and separation performance of the as-synthesized membranes were investigated. It was found that in-situ aging temperature and microwave heating time had the most significant influences on the synthesis. LTA zeolite membranes synthesized by "in-situ aging-microwave heating" method showed superior gas permeation properties (permeance of H-2 = 1.71 x 10(-7) mol m(-2) s(-1) pa(-1), permselectivities for H-2/N-2 and H-2/C3H8 were 5.60 and 9.17, respectively). Through this method, LTA zeolite membranes with excellent pervaporation performance were prepared with high reproducibility. This convenient and effective method paved a promising way toward mass production of LTA zeolite membranes. (c) 2005 Elsevier B.V. All rights reserved

MOF基膜反应器中生物质催化转化

Catalytic Biomass Conversion in MOF-based Membrane Reacto

具有优异的透氧性能的双相膜反应器用于合成气生产

DUAL-PHASE MEMBRANE REACTOR FOR SYNGAS PRODUCTION WITH IMPROVED OXYGEN PERMEABILIT

mixedconductoroxygenpermeablemembranereactors

This article reviews the catalytic reactions in mixed conductor oxygen permeable membrane reactors. A basic principle of oxygen permeation through the membranes is first introduced, followed by a discussion on the properties of membrane materials including their structure, composition, and the sorts of inorganic membrane reactors and their benefits. The main part of this review gives an intensive discussion on the partial oxidation of methane in mixed conductor membrane reactors and the development of membrane materials for this reaction. Several reactions, such as oxidative coupling of methane, oxidative dehydrogenation of ethane, hydrogen production from water splitting, and decomposition of carbon dioxide, in mixed conductor membrane reactors are summarized