Preparation of mesoporous Beta zeolite by fluoride treatment in liquid phase. Textural, acid and catalytic properties

SiO2/Al2O3 Mole Ratio: 25-200

Nominal Cation Form: Sodium/Hydrogen

Na2O Weight %: 0.1

Surface Area, m2/g: 540

Zeolite beta

Highlights
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Zeolite Beta (Si/Al = 19) can be etched with HF/NH4F solutions at mild conditions.

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The crystallinity is retained while the pore volume increases.

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Crystals of sponge-like morphology are formed.

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A fraction of the extraframework aluminum is reinserted in framework positions.

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Activity in m-xylene reaction depends on acid strength and Bronsted/Lewis ratio.

Abstract
Beta zeolite (nominal Si/Al = 19) has been treated with HF/NH4F solutions under different HF concentration, temperature and reaction time. It has been found that the crystallinity of the resulting materials is >80% for HF concentration up to 0.5 M, but it drops below this value for the most severe condition (HF = 1 M and 40 °C). The treatment dissolves selectively aluminum, in such a way that the Si/Al increases to 34 for the most attacked material. As a consequence of these treatments, the mesopore volume increases by up to 80% respect to the parent Beta for samples retaining high crystallinity, corresponding to newly created mesopores in the range of 5–20 nm. Detailed STEM-HAADF studies reveal that the chemical attack of the Beta crystals by the acidic fluoride solution progresses slowly along the crystals, leaving behind highly corroded and porous “sponge-like” crystals where the structure of the zeolite is nevertheless retained. Pyridine adsorption/desorption experiments show that a fraction of the extraframework Al present in the starting Beta is reinserted in framework sites, a process that would be mediated by aluminum-fluoride soluble species. As a consequence of this process, the Bronsted/Lewis ratio of the strong acid sites increases from 1 in the starting Beta to close to 3. The concentration of total and strong Bronsted acid sites associated to framework Al increases with the treatment. However, the activity of the samples in the isomerization/disproportionation of m-xylene is lower than that of the parent Beta zeolite, a result that could be due to the higher B/L ratio.

β molecular sieves have three mutually intersecting 12-ring channels, it is only 12 yuan a three-dimensional pore structure of zeolite ring.

β zeolite having high hydrocracking, hydroisomerization catalytic activity and adsorption capacity of linear paraffins, and good resistance to sulfur and nitrogen poisoning. It can be used in the petrochemical industry of benzene with propylene olefin system cumene, cumene metathesis diisopropylbenzene, toluene Isopropylation, aromatics alkylation, transalkylation diisopropylbenzene, propylene ether, methanol aryl structured, propylene oxide and acetic ether of phenol methylation, methylation of aniline, toluene transalkylation preparation of cumene and toluene disproportionation and transalkylation reaction with a catalyst such. β-type USY zeolite used in conjunction with the increase of the octane number of gasoline. In the fine chemical industry, β zeolite has excellent activity and selectivity in the dehydration deamination.

Beta zeolite 25

Beta zeolite 28

Beta zeolite 30

Beta zeolite 50

Zeolite beta is used in isomerization of waxes, and Friedel Crafts reactions (alkylation and acylation)Zeolite β, hydrogen is used as a molecular sieve, filter, adsorbent, catalyst, drying agent, cation exchanger, dispersing agent and detergent builder. It serves as an acid catalyst and utilized as an alternative to the known methods for protection of alcohols as tetrahydropyranyl ethers and the deprotection of tetrahydropyranyl ethers. It is also used in the stereoselective Meerwein-Ponndorf-Verley reduction of ketones. Further, it is used as an efficient and recyclable catalyst for the tetrahydropyranylation of alcohols and phenols

We can produce beta zeolite according customers demand.

Our zeoite and catalyst factory are in follow.

The fixed-bed catalyst production project covers an area of about 5,000 square meters and a building area of 2,000 square meters. It is fully equipped with public works and has more than 40 sets of catalyst production equipment. It has a complete fixed-bed catalyst production system, and the production units that can be carried out mainly include: pretreatment of catalyst raw powder, impregnation, molding, drying/roasting, screening and environmental protection treatment, etc., which can meet the production of various fixed-bed catalysts.