n-Hexane aromatization on synthetic gallosilicates with MFI structure

Structural Characterization of the Gallosilicate TsG-1, K10Ga10Si22O64·5H2O, with the CGS Framework Topology

“…The substitution of Al by Ga is common and has been proposed, for example, as a means to control pore dimension 3,4 and increase para-selectivities for the alkylation of ethylbenzene 5 and for other gallium-promoted catalysis 6 such as the conversion of n-hexane. 7 The modification of existing aluminosilicate frameworks, or the complete substitution of Al with Ga in known aluminosilicate frameworks, is widely reported. 8 There are however few reports of microporous materials unique to gallosilicate chemistry.…”

“…13 TsG-1 has an interpenetrated double 6-ring building unit (4 10 6 3 8 2 ) (Figure 2), which is unique to the CGS framework. 12 This building unit is closely related to the double 6-ring of group 4 zeolites 14 such as CHA, GME, FAU, ZK-5, and AEI, but has not been observed in (11) Crystal structure of TsG-1: K10Ga10Si22O64‚5H2O, M ) 1942.8 (7), orthorhombic, Pnma, Z [1] ) 8, a ) 8.613(2) Å, b ) 13.813(3) Å, c ) 16.330(3) Å, was studied using a needle-shaped crystal (10 × 12 × 150 µm) at 293(2) K. All experiments were carried out at the SUNY X3A beamline at the National Synchrotron Light Source (NSLS). A 0.643 Å X-ray beam monochromated by a Si(111) crystal was used.…”

Aromatization of waste polyolefin pyrolysate over H-ZSM-5 zeolite-supported gallium oxide catalysts

“…Such a lack of dependence of product distribution on the source alkane has also been reported for C3-C8 alkane aromatization reactions over gallium-containing zeolite catalyst. [4][5][6][7][8] These results are explained by a reaction mechanism that involves the cracking of long-chain alkane pyrolysate to light hydrocarbons, followed by oligomerization and dehydrocyclization to BTXs. 9 Hydrogen chloride generally causes demetalation of the zeolitic framework, which results in an irreversible deactivation of the catalyst.…”

“…[1][2][3] Recently, some gallium-containing zeolite catalysts that convert alkanes to aromatic hydrocarbons, mainly benzene, toluene, and xylene (BTX), in good yields have been reported. [4][5][6][7][8] In particular, Uemichi et al have applied hydrothermally synthesized gallium silicate as an aromatization catalyst for polyolefi ns. 9,10 This process has the advantage that the fi nal products are versatile petrochemical feedstocks.…”

Synthesis of Zeolite Catalysts Containing Zn and Ga for Aromatization of <i>n</i>-Hexane

“…In contrast to [Zn]-MFI and [Ga]-MFI, [Zn,Ga]-MFI (Si/(Zn Ga) 10 and Zn/Ga 1/1) showed quite low catalytic activity for the conversion of n-hexane, although Ga species was introduced into the zeolite. Considering influences of the crystallinity of zeolite catalysts in the catalytic properties 26) , we investigated the catalytic properties of [Zn,Ga]-MFI (Si/(Zn Ga) 10 and Zn/ Ga 1/1) prepared using sodium cations (Fig. 6).…”