Synthesis of High-silica CHA Zeolite from FAU Zeolite in the Presence of Benzyltrimethylammonium Hydroxide

Abstract

A highly crystalline and pure high-silica chabazite zeolite with a Si/Al ratio of ca. 17 was obtained by the hydrothermal conversion of FAU zeolite used as a crystalline Si/Al source in benzyltrimethylammonium hydroxide media.

Hydrothermal conversion of FAU zeolite into LEV zeolite in the presence of non-calcined seed crystals

“…The rotor was spun at 4 kHz for 13 C CP/MAS and 29 Si MAS NMR, and at 6 kHz for 27 Al MAS NMR. The spectra were acquired using 6.0 ms pulses, a 25 s recycle delay, and 1000 scans for 13 …”

“…Recently, our group has also investigated the potential of interzeolite conversion, and succeeded in the synthesis of several types of zeolites such as *BEA, RUT, CHA, LEV, MTN, and OFF using FAU zeolite as the starting material in the presence of various OSDAs [11][12][13][14][15][16]. Among the zeolites synthesized, LEV zeolite, which belongs to the chabazite (CHA) zeolite group, has attracted considerable interest because of its structure with eight-membered ring pores (4.8 Â 3.6Å) and because it shows a shape specific selectivity for the conversion of methanol or ethanol into light olefins such as ethylene and propylene.…”

Influence of starting zeolite on synthesis of RUT type zeolite by interzeolite conversion method

“…First, in order to investigate the potential of interzeolite conversion of n BEA type zeolites into RUT type zeolites, we attempted the hydrothermal conversion of n BEA type zeolites using TMAOH, BTMAOH, and choline hydroxide, which were previously reported to be effective for interzeolite conversion of FAU type zeolites [16][17][18][19][20][21]. The synthesis conditions and products obtained are listed in Table 1.…”

“…Kubota et al [14] and Ahedi et al [15] also succeeded in the interconversion of Al-n BEA and Ti-n BEA into Al-SSZ-31 and Ti-SSZ-24, respectively. Very recently, we also succeeded in synthesizing n BEA, CHA, MTN, LEV, OFF, and RUT type zeolites using FAU type zeolite as the starting zeolite in the presence of a variety of SDAs such as tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), benzyltrimethylammonium hydroxide (BTMAOH), and choline hydroxide [16][17][18][19][20][21]. In the hydrothermal conversion of FAU type zeolite, it was found that when SDA is also employed as an alkali source, the use of FAU type zeolite as a starting material shows the enhanced crystallization rate zeolite as compared to amorphous silica/alumina, which are usually used as starting materials for the conventional zeolite synthesis.…”

The synthesis of SSZ-13 with mixed template and it's catalytic performance for methanol to olefins reaction

“…As synthesized zeolite without or with cheaper SDA is more competitive in commercial field [11,12], a lots efforts have been applied to generating improved methods for the synthesis CHA-type zeolite by using a small amount of TMADA + or other unexpensive SDAs. Very recently, there are a few of papers published related with the synthesis of SSZ-13, in which benzyl trimethyl ammonium cation (BTMA + ) instead of a typical SDA [13,14]. We have tried many times to synthesis SSZ-13 only used BTMA + as SDA and result with an impure phase of CHA zeolite.…”