Layered zeolites and their delaminated structures are novel materials that enhance the catalytic performance of catalysts by addressing diffusion limitations of the reactant molecules. n-Hexane catalytic cracking was observed over MCM-22 layered zeolite and its derivative structures over the temperature range of 450-650 °C for the production of olefins. MCM-22, H-MCM-22, and ITQ-2 zeolites were prepared by the hydrothermal method. Oxalic acid was used as a dealuminating reagent to obtain H-MCM-22 with various Si/Al ratios ranging from 09-65. The prepared samples were characterized by XRD, SEM, TGA, and BET. The cracking of n-hexane was carried out by Pyro/GC-MS. It was observed that the selectivity for olefins was improved by increasing the Si/Al ratio. H-MCM-22-10% produced the highest relative olefinic concentration of 68% as compared to other dealuminated structures. Moreover, the product distribution showed that higher reaction temperature is favorable to produce more olefins. Furthermore, a comparison between ITQ-2 and MCM-22 derived structures showed that ITQ-2 is more favorable for olefins production at high temperatures. The concentration of relative olefins was increased up to 80% over ITQ-2 at 650 °C.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7733465 | PMC |
http://dx.doi.org/10.1038/s41598-020-78746-9 | DOI Listing |
Pharmaceutics
August 2024
Department of Pharmaceutics, Jiangsu Agri-Animal Husbandry Vocational College, No. 8, Fenghuang East Road, Taizhou 225300, China.
Molecules
August 2024
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
γ-valerolactone (GVL), derived from biomass, is a crucial platform compound for biofuel synthesis and various industrial applications. Current methods for synthesizing GVL involve expensive catalysts and high-pressure hydrogen, prompting the search for greener alternatives. This study focuses on a novel zirconium phosphate (ZrP)-pillared zeolite MCM-36 derivative catalyst for converting levulinic acid (LA) to GVL using alcohol as a hydrogen source.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
April 2024
School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang, Anhui 236037, PR China. Electronic address:
In this work, a stable ratiometric nanofluorescent probe for the detection of 2,6-dipicolinic acid (DPA), a Bacillus anthracis biomarker, was developed based on confinement-induced emission enhancement of cationic styrylpyridine salt derivative L in MCM-22 molecular sieve pores. The cationic L and the lanthanide Tb were loaded into the pores of the molecular sieve by electrostatic interaction with the negatively charged AlO tetrahedron unit, and L exhibited enhanced red fluorescence emission as a stable fluorescence reference mark in the nanoprobe platform due to the restricted molecular torsion of L in the pores of MCM-22. At the same time, the characteristic green fluorescence emission of Tb can be excited by energy transfer due to the "antenna effect" of DPA.
View Article and Find Full Text PDFLayered zeolites and their delaminated structures are novel materials that enhance the catalytic performance of catalysts by addressing diffusion limitations of the reactant molecules. n-Hexane catalytic cracking was observed over MCM-22 layered zeolite and its derivative structures over the temperature range of 450-650 °C for the production of olefins. MCM-22, H-MCM-22, and ITQ-2 zeolites were prepared by the hydrothermal method.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!