synthesis of high-silica aluminosilicate zeolites

[...]... structures identical with those of many high-silica zeolites The preparation methods covered are also confined to direct synthesis methods The preparation of high-silica zeol ites by dealumination methods is not considered Faced with the problem of keeping track of many new zeolites, or claimed as such in the patent literature, with the help of many students and technicians a number of standard recipes have... PTFE-l ined version of these autoclaves is shown in Fig 1.1 Twenty of such autocl aves coul d be mounted together ina furnace and heated while they are being rotated at 50 rpm (rotations per minute) In each autoclave from 10 to 15 g of zeolite on a dry calcined basis can generally be recovered GENERAL PROCEDURE USED FOR THE SYNTHESIS OF HIGH-SILICA ZEOLITES For the synthesis of high-silica zeolites, in most... defined as the weight 4 65 ~I o CO) , ~-:050rpm I" 40 ~I FIGURE 1.1 Technical drawing of the PTFE-lined version of autoclaves used for the synthesis of laboratory-scale amounts of high-silica zeolites Dimensions in millimetres 5 TABLE 1.1 Origin of reactants used in the recipes for the synthesis of high-sil ica zeolites REACTANT ORIGIN GRADE Aeros il-200 Silicic acid Water glass Ludox AS30 Ludox AS40... Al-free ZSM-39 after a synthesis period of 2 days at 433 K The efficiency of this synthesis was 100 %, which indicates that all the sil ica present in the gel was transformed completely into crystalline silica 4 Synthesis of high-silica ZSM-6 with TMA Example 1 of ref 5 has been modified by replacing TMA-Cl with TMA-Br, increasing the synthesis temperature by 30 K and decreasing the synthesis time from... necessarily the most advantageous reactants for the synthesis of bulk amounts of zeolites but their prices are such that the average budget of a university laboratory will permit the synthesis of kilogram amounts of these materials The recipes advanced here are highly reproducible They were checked independently by two laboratory technicians Each synthesis was carried out in home-made stainless-steel... the ZSM-34 showed an Si/A1 2 ratio of 10 The XRD of ZSM-34 looks like the one of offretite materials and possibly the material belongs to the offretite-erionite family 2 Synthesis of ferrierite/ZSM-35-type materials Based on their X-ray diffractograms, ZSM-35, -38 and -21 and ferrierite are not easily distinguishable and therefore belong possibly to the same family of zeolites The distinction made in... SCOPE OF THE WORK This work certainly does not have the pretension to be a complement to the famous books by Breck (ref l ) and Barrer (reL2) and also it was not the authors' aim to write an exhaustive review of high-silica zeolites First of all, the zeolites denoted as high-silica are not well defined, from either a scientific or a compositional point of view Those using this term tacitly assume that high-silica. .. gel with a pH of 12 was transferred into a glass-l ined autoclave and kept at 453 K for 7 days The autoclave was not agitated in this synthesis In this way the following gel : 13 was converted into a crystalline high-silica mordenite The efficiency of the operation was only 60 % 6 Synthesis of ZSM-12 6.a ~?~:!~_~~!~s_I~~ Example 4 of ref 7 was the basis of this recipe Only the nature of the product... + Z.Z g NaOH + Z.7 g A1Z(S04)3.18HZO Synthesis conditions : 473 K for 1 day with agitation The molar composition of the gel was in which R represents piperidine The efficiency was 65 % and the Si/A1 Z ratio of the zeol ite was ZO The modification consisted in the use of Ludox as the silica source and in an increase of the synthesis temperature by 50 K 3 Synthesis of lSM-39 3.a ~t~!b~~!~_2!_~~~:~~_~2!b_e!e~~!92~~_~~_!b~_2~9~~!~_~~!~~!~!... Preparation of Heterogeneous Catalysts Proceedings of the Fourth International Symposium, Louvain-Ia-Neuve, September 1-4,1986 edited by B Delmon P Grange P.A Jacobs and G Poncelet Volume 32 Thin Metal Films and Gas Chemisorption edited by P Wissmann Volume 33 Synthesis of High-silica Aluminosilicate Zeolites by P.A Jacobs and J.A Martens XII XIII TO JAN B UYTTERHOEVEN Who we consider to be the founder of all . 6 1. Synthesis of ZSM-34 6 2. Synthesis of ferrieritejZSM-35-type materials 8 3. Synthesis of ZSM-39 10 4. Synthesis of high-silica ZSM-6 with TMA 11 5. Synthesis of high-silica mordenite 12 6. Synthesis. Synthesis of ZSM-12 13 7. Synthesis of zeolite PHI 15 8. Synthesis of zeolite BETA 16 9. Synthesis of zeolite ZSM-25 17 10. Synthesis of ZSM-5 with TPA 17 11. Synthesis of ZSM-ll 20 12. Synthesis of ZSM-8 21 13 Synthesis of ZSM-5 different from TPA * Synthesis of ZSM-5 * Synthesis of ZSM-5 * The use of various * Synthesis of ZSM-5 * References in the presence of quaternary ammonium cations in the presence of