Effect of cation location on the hydrothermal stability of rare earth-exchanged Y zeolites

Du, Xiaosheng; Gao, Xionghou; Zhang, Haitao; Li, Xueli; Liu, Pusheng

doi:10.1016/j.catcom.2013.02.010

Cited by 60 publications

(37 citation statements)

References 21 publications

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“…To accurately control the acid properties, various strategies such as doping with rare earth ions [10,11], controlling of crystal size [12,13], and modulating silica to alumina ratio (SiO 2 /Al 2 O 3 ) [1,14,15], have been extensively studied. Additionally, acid properties can also be directly adjusted by optimizing the SiO 2 /Al 2 O 3 ratio in the formulation of raw material in the crystallization synthesis of Y; however, this method is limited by the synthetic conditions.…”

Section: Introductionmentioning

confidence: 99%

High performance of H3BO3 modified USY and equilibrium catalyst with tailored acid sites in catalytic cracking

Feng

Yan

et al. 2017

Microporous and Mesoporous Materials

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Increasing the cracking ability of catalyst by adjusting its surface acid property is of great significance for oil refining industry. The effects of boric acid on the structure and surface acidity of ultra stabilized Y (USY) and FCC equilibrium catalyst during the modification were investigated. The structural and surface properties of the prepared samples were characterized by low-temperature N 2 sorption, XRD, 27 Al and 29 Si MAS NMR, and FTIR using pyridine probe molecule. Modified USY and equilibrium catalyst possessed reduced Lewis acid sites. The Brönsted/Lewis acid ratios of USY increased from 0.64 to 1.56 after modification, at the same time, the microporous surface areas increased, due to the nonframework and framework dealumination during the modification. The catalytic cracking tests were performed on a bench-scale micro reactor at 500°C and atmospheric pressure, using n-dodecane as a modeling reactant and vacuum gas oil as conventional feedstock. The results showed that

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Section: Introductionmentioning

confidence: 99%

High performance of H3BO3 modified USY and equilibrium catalyst with tailored acid sites in catalytic cracking

Feng

Yan

et al. 2017

Microporous and Mesoporous Materials

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“…To study the effect of hydrothermal treatment, two sets of experiments were performed by aging all catalysts at 700 and 800°C for The slight decrease of NO conversions for the catalysts hydrotreated at 700 °C, 800 °C and 850 °C can be related to the presence of cerium cations into the sodalite cages of the zeolite Na-F. Actually, during the preparation of the catalyst Ce (20)-F C , the latter was calcined at higher temperature (750 °C) compared to the other catalysts (450 °C). The use of this higher calcination temperature permits to the cerium cations to migrate from the supercage to the sodalite cage and to form bridges with the oxygen framework which stabilize the zeolites tructure [46,47]. Y. Shu et al [46] reported that the hydrothermal treatment of zeolite catalysts at high temperatures (500-800°C), provokes the dealumination of the framework especially for those having low Si/Al ratio.…”

Section: Hydrothermal Stabilitymentioning

confidence: 99%

“…Thus, one can conclude that the cerium cations are not agglomerated and welldispersed into the zeolite porosity[30,31]. In general, with calcination at high temperature (>300 °C), cerium ions located in the supercages starts to migrate to the sodalite cage and are stabilized by the framework oxygens[33]. All catalysts have a light yellow color, this observation indicates the presence of cerium tetravalent[34].On the other hand, the crystallinity of the catalysts decreased as the percentage of cerium increased.…”

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confidence: 91%

Selective catalytic reduction of NO by NH3 on cerium modified faujasite zeolite prepared from aluminum scraps and industrial metasilicate

Abid

Delahay

Tounsi

2020

Journal of Rare Earths

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This work was devoted to the study of the selective catalytic reduction of NO by NH 3 on calcined and hydrothermal treated cerium loaded zeolite catalysts. The parent faujasite zeolite Na-F (Si/Al = 1.32 and S BET = 749 m 2 /g) used as support for the preparation of the catalysts was obtained from industrial sodium metasilicate and aluminum scraps. As expected, the NO conversion increased with increasing the percentage of cerium in the structure of the faujasite zeolite. Total NO conversion into N 2 was reached at 400°C at a space velocity of 250,000 h-1. The high conversion is due to the redox shift between Ce 3+ / Ce 4+ and the strong acid sites related to the rare earth present in the framework that is the key in SCR of NO process. Moreover, the highest loaded cerium catalyst retained high almost its activity after thermal hydrotreatment at 850°C. This higher loading is desirable for both activity and stability provided that two stages of preparation are used to put the Ce ions in the sodalite cages.

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“…Fluid catalytic cracking (FCC) is an important process for crude oil, in which FCC catalysts have played a key role [ 1 , 2 , 3 ]. Recently, with crude oil becoming increasingly inferior, the demand for an excellent catalytic cracking performance of FCC catalysts has greatly increased [ 4 , 5 , 6 , 7 , 8 ]. Usually, FCC catalysts are made of zeolites, a binder, and a matrix material.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Si-Modified Pseudo-Boehmite@kaolin Composite and Its Application as a Novel Matrix Material for FCC Catalyst

Yuan

Zhou

et al. 2022

Materials

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Fluid catalytic cracking (FCC) has been the primary processing technology for heavy oil. Due to the inferior properties of heavy oil, an excellent performance is demanded of FCC catalysts. In this work, based on the acid extracting method, Si-modified pseudo-boehmite units (Si-PB) are constructed in situ and introduced into the structure of kaolin to synthesize a Si-PB@kaolin composite. The synthesized Si-PB@kaolin is further characterized and used as a matrix material for the FCC catalyst. The results indicate that, compared with a conventional kaolin matrix, a Si-PB@kaolin composite could significantly improve the heavy oil catalytic cracking performance of the prepared FCC catalyst because of its excellent properties, such as a larger surface area, a higher pore volume, and a good surface acidity. For the fresh FCC catalysts, compared with the FCC catalysts using conventional kaolin (Cat-1), the gasoline yield and total liquid yield of the catalyst containing Si-PB@kaolin (Cat-2) could obviously increase by 2.06% and 1.55%, respectively, with the bottom yield decreasing by 2.64%. After vanadium and nickel contamination, compared with Cat-1, the gasoline yield and total liquid yield of Cat-2 could increase by 1.97% and 1.24%, respectively, with the bottom yield decreasing by 1.80 percentage points.

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Effect of cation location on the hydrothermal stability of rare earth-exchanged Y zeolites

Cited by 60 publications

References 21 publications

High performance of H3BO3 modified USY and equilibrium catalyst with tailored acid sites in catalytic cracking

High performance of H3BO3 modified USY and equilibrium catalyst with tailored acid sites in catalytic cracking

Selective catalytic reduction of NO by NH3 on cerium modified faujasite zeolite prepared from aluminum scraps and industrial metasilicate

Synthesis of Si-Modified Pseudo-Boehmite@kaolin Composite and Its Application as a Novel Matrix Material for FCC Catalyst

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