posted on 2022-01-25, 16:33authored byBastian Reiprich, Karolina A. Tarach, Kamila Pyra, Gabriela Grzybek, Kinga Góra-Marek
Layer-like FAU-type
zeolite Y was synthesized by an organosilane-assisted
low-temperature hydrothermal method and its catalytic activity was
verified in the low-density polyethylene (LDPE) cracking process.
The synthesis procedure of high-silica layer-like zeolite Y was based
on organosilane as a growth modifier, and for the first time, the
seeding step was successfully avoided. The X-ray diffraction and electron
microscopy studies, scanning electron microscopy and transmission
electron microscopy confirmed the formation of pure FAU structure
and zeolite particles of plate-like morphology arranged in the manner
of the skeleton of a cuboctahedron. The in situ Fourier
transform infrared (FT-IR) spectroscopic studies, low-temperature
nitrogen sorption, and electron microscopy results provided detailed
information on the obtained layer-like zeolite Y. The acidic and textural
properties of layer-like zeolites Y were faced with the catalytic
activity and selectivity in the cracking of LDPE. The quantitative
assessment of catalyst selectivity performed in FT-IR/GC–MS operando studies pointed out that LDPE cracking over the
layer-like material yielded value-added C3–C4 gases and C5–C6 liquid fraction
at the expense of C7+ fraction. The detailed analysis of
coke residue on the catalyst was also performed by means of FT-IR
spectroscopy, thermogravimetric analysis, and thermoprogrammed oxidation
coupled with mass spectrometry for the detection of oxidation products.
The acidic and textural properties gave a foundation for the catalytic
performance and coking of catalysts.