Hydrogenolysis of Polyethylene and Polypropylene into Propane over Cobalt-Based Catalysts
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jacsau.2c00402.pdf
Description
Published version
Size
3.55 MB
Format
Adobe PDF
Checksum (MD5)
d7c9b7ec51e2491b33c06804a54282e7
Author(s)
Zichittella, Guido
Ebrahim, Amani M
Zhu, Jie
Brenner, Anna E
Drake, Griffin
Beckham, Gregg T
Bare, Simon R
Rorrer, Julie E
Román-Leshkov, Yuriy
Date Issued
October 24, 2022
Journal
JACS Au
Publisher
American Chemical Society (ACS)
Citation
Zichittella, Guido, Ebrahim, Amani M, Zhu, Jie, Brenner, Anna E, Drake, Griffin et al. 2022. "Hydrogenolysis of Polyethylene and Polypropylene into Propane over Cobalt-Based Catalysts." JACS Au, 2 (10).
Version
Final published version
Abstract
The development of technologies to recycle polyethylene (PE) and polypropylene (PP), globally the two most produced polymers, is critical to increase plastic circularity. Here, we show that 5 wt % cobalt supported on ZSM-5 zeolite catalyzes the solvent-free hydrogenolysis of PE and PP into propane with weight-based selectivity in the gas phase over 80 wt % after 20 h at 523 K and 40 bar H2. This catalyst significantly reduces the formation of undesired CH4 (≤5 wt %), a product which is favored when using bulk cobalt oxide or cobalt nanoparticles supported on other carriers (selectivity ≤95 wt %). The superior performance of Co/ZSM-5 is attributed to the stabilization of dispersed oxidic cobalt nanoparticles by the zeolite support, preventing further reduction to metallic species that appear to catalyze CH4 generation. While ZSM-5 is also active for propane formation at 523 K, the presence of Co promotes stability and selectivity. After optimizing the metal loading, it was demonstrated that 10 wt % Co/ZSM-5 can selectively catalyze the hydrogenolysis of low-density PE (LDPE), mixtures of LDPE and PP, as well as postconsumer PE, showcasing the effectiveness of this technology to upcycle realistic plastic waste. Cobalt supported on zeolites FAU, MOR, and BEA were also effective catalysts for C2-C4 hydrocarbon formation and revealed that the framework topology provides a handle to tune gas-phase selectivity.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1021/jacsau.2c00402
