Dealumination and characterization of chabazite for catalytic application

Shin, Hye Sun; Jang, Ik Jun; Shin, Na Ra; Kim, Su Hyun; Cho, Sung June

doi:10.1007/s11164-011-0390-z

Cited by 22 publications

(4 citation statements)

References 3 publications

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“…At the same temperature, MFI synthesis from FAU requires a higher A structure less dense than the starting one is formed 2 FAU CHA d6r -(K + ) [25] It has been directly found that a common block is retained. Si/Al ratio does not exceed 6, and the product can be dealuminated only using AHFS [26]. The synthesis can occur in the absence of free water.…”

Section: Interzeolite Transformation Regularitiesmentioning

confidence: 99%

Interzeolite Transformations as a Method for Zeolite Catalyst Synthesis

2021

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This review presents the achievements of the last 10-15 years in interzeolite transformations as a method for synthesizing high-performance zeolite catalysts. The main regularities and mechanisms of interzeolite transformations are analyzed. The paper describes a variety of examples where interzeolite transformations ensured a successful synthesis of zeolite structures which either could not be prepared from amorphous sources or required the use of expensive templates. The advantages of zeolite catalysts synthesized by interzeolite transformation, compared to those obtained from amorphous sources, are demonstrated.

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Section: Interzeolite Transformation Regularitiesmentioning

confidence: 99%

Interzeolite Transformations as a Method for Zeolite Catalyst Synthesis

2021

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“…In contrast to the other zeolite topologies, the modification of the CHA framework by mesopore generation is still an open field for scientists. The reports presenting studies in this area are connected with the following methods of CHA modification: (i) preparation of the hierarchical CHA structure using the supramolecular (double templating) method [23e25] e.g., for the CO 2 capture under moderate temperatures and high pressure conditions, (ii) desilication of SSZ-13 with NaOH solution for the application in the methanol-to-olefin (MTO) process [26], (iii) dealumination of CHA and SSZ-13 zeolites using ammonium hexafluorosilicate [27] and (iv) the generation of mesopores by solid templating using carbon nanoparticles or nanotubes [28].…”

Section: Introductionmentioning

confidence: 99%

Modification of the physicochemical properties of the commercial CHA zeolite and examination of its activity in nitrogen oxide abatement

Rutkowska

Duda

Kowalczyk

et al. 2017

Comptes Rendus. Chimie

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In this manuscript, studies of catalytic activity in two environmental processes were performed: NO reduction with NH 3 (DeNO x process) and N 2 O decomposition over the commercial CHA zeolite. In the first part of the studies, the parent CHA zeolite was modified with different contents of copper (1, 5, 10 and 15%) by wet impregnation, and optimum Cu loading was chosen. In the second part of the studies, CHA was modified by the use of different bases and acids (NaOH, TPAOH (tetrapropylammonium hydroxide), HCl, and Na 2 H 2 EDTA (ethylenediaminetetraacetic acid)) in order to generate mesoporosity. The influence of demetallation agent concentration, temperature and duration of treatment was examined. The most efficient treatment, resulting in an almost four-fold increase in the mesopore volume, was found to be with a 0.2 M Na 2 H 2 EDTA solution (treatment for 4 h at 100 C). Moreover, despite the modification of the textural properties, the phase composition, acidity and form of the introduced copper species were also influenced by the applied modification techniques (the samples were examined with the use of techniques such as N 2 sorption, XRD, NH 3 -TPD and UVevis-DRS). The Cu-CHA samples obtained with the use of commercial zeolite supplied by Clariant (Germany) exhibited high activity in the DeNO x process under the applied conditions. The stability of the Cu-CHA sample (doped with 5% of Cu) in the DeNO x process was examined by five subsequent catalytic runs, and only a small drop in catalytic activity was observed. Moreover, the treatment of CHA with Na 2 H 2 EDTA increased its activity in N 2 O decomposition, which makes the applied modification techniques interesting for the potential application of this zeolite in catalysis.

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“…SSZ-13 zeolites have been synthesized via various methods, including direct synthesis (from precursors of silica and alumina) and conversion of zeolite Y. For the synthesis of SSZ-13s, various templates, such as N,N,Ntrimethyl-1-adamantanamine iodide (TMAda-I) [5,7], TMAda-OH [8][9][10][11][12], choline chloride [13,14], copper-tetraethylenepentamine (Cu-TEPA) [15][16][17], tetraethylammonium hydroxide (TEA-OH) [18], benzyltrimethylammonium hydroxide [19], and N,N,Ndimethylethylcyclohexylammonium bromide [20] have been used despite several reports of its template-free [21][22][23][24] synthesis.…”

Section: Introductionmentioning

confidence: 99%