Intra-Crystalline Mesoporous Zeolite [Al,Zr]-Y for Catalytic Cracking

Abstract

A facile, direct, and template-free synthesis of intracrystalline mesoporous zeolite Y involving the introduction of Zr atoms under hydrothermal conditions is proposed for the first time. The presence of mesopores in the product was confirmed by N2 adsorption–desorption isotherms and transmission electron microscopy, while the results of UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, 29Si MAS NMR spectroscopy, and Fourier-transform infrared spectroscopy analyses confirmed that Zr atoms were successfully introduced to the zeolite framework. The density functional theory was used hypothesize the origin of the mesopores. Compared with conventional USY (ultrastable Y) zeolite, [Al,Zr]-USY zeolite has an excellent mesoporous structure because of the framework mesoporous defects of [Al,Zr]-NaY. A catalytic study performed using the cracking of 1,3,5-triisopropylbenzene as a model application revealed that the [Al,Zr]-USY zeolite exhibits superior activity to that of typical USY zeolite. Thus, this synthetic method provides a convenient and environmentally benign strategy for the synthesis of hierarchical zeolites, particularly for use in the fluid catalytic cracking industry, in which zeolites are routinely applied as cracking catalysts.

In Situ Synthesis of Cation-Free Zirconia-Supported Zeolite CHA Membranes for Efficient CO2/CH4 Separation

“…A minor vibration band at 965 cm –1 appeared for the Zr–Si-CHA sample, which corresponded to an asymmetric stretching of [O 3 Si–O–Zr] with the Zr tetrahedron, suggesting the substitution of Zr with Si in the zeolite CHA framework . The wavenumbers can be calculated by Hooke’s law and are inversely proportional to the masses of the bonded atoms . Hooke’s law is as follows: normalΣ ⁢ 0.25em = 1 2 normalΠ C k M , 0.25em M = m 1 m 2 m 1 + m 2 .…”

“…The wavenumbers can be calculated by Hooke’s law and are inversely proportional to the masses of the bonded atoms . Hooke’s law is as follows: . The wavenumbers for the Zr–Si-CHA sample shifted to lower wavenumbers as shown in Figure , indicating that the silicon T atom is substituted by the larger mass of the Zr tetrahedron.…”

“…2 H o o k e ' s l a w i s a s f o l l o w s : M , 42. The wavenumbers for the Zr−Si-CHA sample shifted to lower wavenumbers as shown in Figure9, indicating that the silicon T atom is substituted by the larger mass of the Zr tetrahedron.…”

Strategy for the synthesis of zeolite Y by artificial-fish-reef breeding negative crystals

“…For Y zeolite, its ultrastable product prepared by steam treatment is often applied as an industrial catalyst for catalytic cracking. [46][47][48] The dealkylation of bulk molecular 1,3,5-triisopropylbenzene (TIPB) is often used to evaluate the catalytic properties of catalysts with different crystal sizes. 11,20,35 The results for the catalytic cracking of TIPB for USY-CPAM and USY-Contrast zeolites are listed in Fig.…”

A Comparative Study on Mesoporous Y Zeolites Prepared by Hard-Templating and Post-Synthetic Treatment Methods

“…Fan). been made by both industrial and academic communities to improve the accessibility of zeolites in order to sustain or improve their catalytic effectiveness [8][9][10][11][12][13]. To alleviate this particular problem associated with microporous zeolites, a class of mesoporous zeolites (or ideally, hierarchical zeolites) was proposed and developed.…”