We report non-degradable polyolefin plastics pose severe environmental threats, and thus demand efficient upcycling technologies. In this work, we discovered that low-loading (= 0.25 wt%) Ru/CeO2 exhibits remarkable catalytic performance in the hydrogenolysis of polypropylene (PP), polyethylene (PE), and n-C16H34 that is superior to high-loading (= 0.5 wt%) Ru/CeO2. They possess high PP conversion efficiency (7-fold increase over current literature reports), low selectivity towards undesired CH4, and good isomerization ability. In the low-loading range, the intrinsic activity of Ru in PP hydrogenolysis increases as the particle size decreases, opposite of the trend in the high-loading range. Detailed characterization revealed that the abrupt changes in catalytic behaviors coincide with Ru species transitioning from well-defined to highly disordered structures in the low-loading domain. The disordered Ru species were shown to be sub-nanometer in size and cationic. Mechanistically, the regioselectivity and the rate dependence on hydrogen pressure of C-C bond cleavage are different on low- and high-loading Ru/CeO2, both explained by the higher coverage of adsorbed hydrogen (*H) on low-loading Ru/CeO2. This work uncovers the remarkable catalytic performance of highly disordered, sub-nanometer, cationic Ru species in polyolefin hydrogenolysis, opening immense opportunities to develop effective, selective, and versatile catalysts for plastic upcycling.
Chen, Linxiao, et al. "Disordered, Sub-Nanometer Ru Structures on CeO<sub>2</sub> are Highly Efficient and Selective Catalysts in Polymer Upcycling by Hydrogenolysis." ACS Catalysis, vol. 12, no. 8, Apr. 2022. https://doi.org/10.1021/acscatal.2c00684
Chen, Linxiao, Meyer, Laura C., Kovarik, Libor, Meira, Debora, Pereira-Hernandez, Xavier I., Shi, Honghong, Khivantsev, Konstantin, Gutiérrez, Oliver Y., & Szanyi, János (2022). Disordered, Sub-Nanometer Ru Structures on CeO<sub>2</sub> are Highly Efficient and Selective Catalysts in Polymer Upcycling by Hydrogenolysis. ACS Catalysis, 12(8). https://doi.org/10.1021/acscatal.2c00684
Chen, Linxiao, Meyer, Laura C., Kovarik, Libor, et al., "Disordered, Sub-Nanometer Ru Structures on CeO<sub>2</sub> are Highly Efficient and Selective Catalysts in Polymer Upcycling by Hydrogenolysis," ACS Catalysis 12, no. 8 (2022), https://doi.org/10.1021/acscatal.2c00684
@article{osti_1862990,
author = {Chen, Linxiao and Meyer, Laura C. and Kovarik, Libor and Meira, Debora and Pereira-Hernandez, Xavier I. and Shi, Honghong and Khivantsev, Konstantin and Gutiérrez, Oliver Y. and Szanyi, János},
title = {Disordered, Sub-Nanometer Ru Structures on CeO<sub>2</sub> are Highly Efficient and Selective Catalysts in Polymer Upcycling by Hydrogenolysis},
annote = {We report non-degradable polyolefin plastics pose severe environmental threats, and thus demand efficient upcycling technologies. In this work, we discovered that low-loading (= 0.25 wt%) Ru/CeO2 exhibits remarkable catalytic performance in the hydrogenolysis of polypropylene (PP), polyethylene (PE), and n-C16H34 that is superior to high-loading (= 0.5 wt%) Ru/CeO2. They possess high PP conversion efficiency (7-fold increase over current literature reports), low selectivity towards undesired CH4, and good isomerization ability. In the low-loading range, the intrinsic activity of Ru in PP hydrogenolysis increases as the particle size decreases, opposite of the trend in the high-loading range. Detailed characterization revealed that the abrupt changes in catalytic behaviors coincide with Ru species transitioning from well-defined to highly disordered structures in the low-loading domain. The disordered Ru species were shown to be sub-nanometer in size and cationic. Mechanistically, the regioselectivity and the rate dependence on hydrogen pressure of C-C bond cleavage are different on low- and high-loading Ru/CeO2, both explained by the higher coverage of adsorbed hydrogen (*H) on low-loading Ru/CeO2. This work uncovers the remarkable catalytic performance of highly disordered, sub-nanometer, cationic Ru species in polyolefin hydrogenolysis, opening immense opportunities to develop effective, selective, and versatile catalysts for plastic upcycling.},
doi = {10.1021/acscatal.2c00684},
url = {https://www.osti.gov/biblio/1862990},
journal = {ACS Catalysis},
issn = {ISSN 2155-5435},
number = {8},
volume = {12},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2022},
month = {04}}
