Dataset Information

Hierarchical Catalysts Prepared by Interzeolite Transformation.

ABSTRACT: Interzeolite transformation has been used to produce a novel family of hierarchical catalysts featuring excellent textural properties, strong acidity, and superior catalytic performance for the Friedel-Crafts alkylation of indole with benzhydrol, the Claisen-Schmidt condensation of benzaldehyde and hydroxyacetophenone, and the cracking of polystyrene. Intermediate solids of the FAU interzeolite transformation into BEA display both increased accessibility─due to the development of mesoporosity─and strong acidity─caused by the presence of ultrasmall crystals or zeolitic fragments in their structure. The use of surfactants allows for the development of the hierarchical catalysts with very narrow pore size distribution. The properties of interzeolite transformation intermediates (ITIs) can be fine-tuned simply by stopping the interconversion at different times.

SUBMITTER: Mendoza-Castro MJ

PROVIDER: S-EPMC8949765 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Hierarchical Catalysts Prepared by Interzeolite Transformation.

Mendoza-Castro Monica J MJ De Oliveira-Jardim Erika E Ramírez-Marquez Nelcari-Trinidad NT Trujillo Carlos-Alexander CA Linares Noemi N García-Martínez Javier J

Journal of the American Chemical Society 20220310 11

Interzeolite transformation has been used to produce a novel family of hierarchical catalysts featuring excellent textural properties, strong acidity, and superior catalytic performance for the Friedel-Crafts alkylation of indole with benzhydrol, the Claisen-Schmidt condensation of benzaldehyde and hydroxyacetophenone, and the cracking of polystyrene. Intermediate solids of the FAU interzeolite transformation into BEA display both increased accessibility─due to the development of mesoporosity─an ...[more]

PMID: 35266382

Similar Datasets

Project description:In this paper, the ultrasonic-assisted desilication technique was reported as an attractive and efficient way for the preparation of hierarchical zeolites with MFI structure type. The prepared materials were used as active catalysts for the dehydration of ethanol into diethyl ether and ethylene. For all catalysts, the selectivity to diethyl ether was ca 95% or higher up to 210 °C, with catalytic activity in the range of 40-68%. In case of desilicated zeolites, at 270-290 °C, the conversion of ethanol was full with selectivity to ethylene ca 80%. MFI-type commercial zeolite was treated with a sodium and/or tetrabutylammonium hydroxide aqueous solutions (NaOH or NaOH/TBAOH) for 30 min. In the case of the application of ultrasounds, a QSonica Q700 sonicator (60 W and 20 kHz) equipped with a "1" diameter horn was used. In all cases, desilication was performed in an ice bath in order to keep the procedure conditions at low temperature. It was indicated that the use of ultrasounds during desilication procedure caused higher extraction of silicon and aluminum, which was connected with an elevated mesoporosity in relation to the samples modified in the absence of ultrasounds. Ultrasonic-assisted treatment of MFI-type zeolite caused also an apparent formation of numerous holes inside zeolite grains, resembling the look of "swiss cheese". Furthermore, it was indicated that the samples prepared using ultrasonic irradiation exhibited enhanced catalytic properties in the dehydration of ethanol. For instance, MFI-type zeolite treated with NaOH/TBAOH alkaline mixture containing 10 mol% of TBAOH in the presence of ultrasounds (M-10 s) demonstrated higher both conversion of ethanol (59% vs. 47%) and selectivity to diethyl ether (95% vs. 93%) in comparison with zeolite modified conventionally (M-10c). The best catalyst was zeolite ultrasonically desilicated with NaOH/TBAOH solution of 70 mol% of TBAOH (M-70s). Generally, this catalyst indicated the highest conversion of ethanol, very high selectivity to diethyl ether (94-100%) at 150-210 °C and the highest selectivity to ethylene among investigated catalysts (21%, 66% and 84%) at 230 °C, 250 oC and 270 °C.

Dataset Information

Hierarchical Catalysts Prepared by Interzeolite Transformation.

Publications

Hierarchical Catalysts Prepared by Interzeolite Transformation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets