Impact of the presence of common polymer additives in thermal and catalytic polyethylene decomposition

Transport limitations in polyolefin cracking at the single catalyst particle level

“…The results offer a different explanation for the conclusion of a recent study that found that HDPE can enter into ZSM-5 micropores. 61 At the temperatures utilized in the study, precracking could cause the decrease in M w and the formation of small molecules, which can enter micropores more easily.…”

Characterization of polymer properties and identification of additives in commercially available research plastics

“…1 For instance, low concentrations of additives such as metals, sulfides, or antioxidants may interfere with new recycling processes. 1,12,13 As examples, Hinton et al demonstrated that antioxidants (0.5-2 wt%) significantly impact the product yields in catalytic hydrocracking of HDPE, 14 and similarly, Jerdy et al showed that antioxidants, and acid scavengers hindered the catalytic upgrading of HDPE plastic pyrolysis oil. 13 Furthermore, physical properties such as molecular mass, branch density and percent crystallinity can impact product yields during catalytic and enzymatic deconstruction of polymers.…”

Precise activation of C–C bonds for recycling and upcycling of plastics

“…However, mesopores tend to exhibit reduced selectivity for reactants, intermediates, or products compared to micropores. 70 The preparation of catalysts with a rich mesoporous structure can signicantly alleviate diffusion limitations and improve the cleavage efficiency of the C aliph -C aliph bond. Bonilla et al discovered that introducing mesopores enhanced the accessibility of active sites, optimizing the diffusion pathway and greatly improving the efficiency of C aliph -C aliph bond activation.…”

“…Furthermore, the diverse branching degree of plastics leads to distinct degradation and diffusion processes in catalysts with identical pore types; meanwhile, this potential connection is intimately linked to the pore morphology. 70,71 It has been conrmed that the microporosity of the catalyst exerts a spatial connement effect on the activation of C aliph -C aliph bonds, which regulates the chemical structure of the products. Manos et al conrmed that larger microporous structures in Y-and b-zeolites facilitate rapid bimolecular hydrogen transfer reactions, resulting in HDPE conversion with alkanes as the main product.…”