Synthesis, characterization and catalytic testing of MCM-22 derived catalysts for n-hexane cracking

Abstract

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.

Catalytic Performance and Sulfur Dioxide Resistance of One-Pot Synthesized Fe-MCM-22 in Selective Catalytic Reduction of Nitrogen Oxides with Ammonia (NH3-SCR)—The Effect of Iron Content

“…It can be noticed from Figure 6 and Figure S1 that the pure MCM-22 consists mainly of the sheet-like small particles. Additionally, the sheets formed relatively regular, donut-like aggregates, which is typical for the lamellar materials [34,53,54]. Furthermore, the reference sample, Fe-IE did not show any noticeable morphological differences, comparing to the support.…”

Sustainable approach for the synthesis of chiral β-aminoketones using an encapsulated chiral Zn(ii)–salen complex

“…Using hexamethyleneimine (HMI) as a template, we synthesized MWW-zeolites using a previously published protocol. 28–30…”

DFT stimulation and experimental insights of chiral Cu(ii)–salen scaffold within the pocket of MWW-zeolite and its catalytic study

“…The MWW zeolite was synthesized using a previously described procedure, [39][40][41] in which a gel mixture with the molar ratios SiO 2 /Al 2 O 3 = 30, Na/SiO 2 = 0.18, HMI/SiO 2 = 0.35 (where HMI = hexamethyleneimine as a template), and H 2 O/SiO 2 = 20.5 was heated at 150 1C for 7 days with rotation (30 rpm). The layered MWW precursor was filtered out and dried at 100 1C before being calcined at 550 1C for 6 hours to produce MWW zeolite.…”