Evaluation of the Synthesis of Zeolite SSZ-13 using Choline Chloride and Different Crystallization Seeds and its Application in the Thermocatalytic Degradation of Ultra-High Molecular Weight Polyethylene

Abstract

The synthesis of SSZ-13 was studied by evaluating the influence of two types of crystallization seeds with CHA structure (S₁ seeds prepared in fluoride medium and S₂ seeds by the conversion of zeolite Y), SiO₂/Al₂O₃ (28, 40, 60 and 100) and OH/SiO₂ (0.6 and 0.8) ratios. Choline chloride was used as the structure-directing agent and the crystallizations occurred at 140 ºC from 24 to 96 h. S₁ seeds led to the coexistence of zeolites SSZ-13 and P, while S₂ seeds promoted in all SiO₂/Al₂O₃ ratios and OH/SiO₂ = 0.8, the formation of pure SSZ-13 after 24 h. The SSZ-13 samples are formed by clusters of crystals with cuboid-like morphology and exhibited textural properties typical of CHA framework. SSZ-13 zeolite led to a decrease in the temperature and the activation energy required for the degradation of ultra-high molecular weight polyethylene polymer, demonstrating its efficiency as catalyst in this process.

Keywords:
Zeolite SSZ-13; Crystallization seeds; Choline chloride; Ultra-high molecular weight polyethylene; Thermocatalytic degradation