TY - JOUR
T1 - Hydrogenative depolymerization of nylons
AU - Kumar, Amit
AU - von Wolff, Niklas
AU - Rauch, Michael
AU - Zou, You-Quan
AU - Shmul, Guy
AU - Ben-David, Yehoshoa
AU - Leitus, Gregory
AU - Avram, Liat
AU - Milstein, David
N1 - This research was supported by the European Research Council (ERC AdG 692775). D. M. holds the Israel Matz Professorial Chair of Organic Chemistry. A. K. is thankful to the Planning and Budgeting Committee of Israel and Feinberg Graduate School for a (senior) postdoctoral fellowship. Y.-Q. Z. acknowledges the Sustainability and Energy ResearchInitiative (SAERI) foundation for a research fellowship. Computations were performed using HPC resources from GENCI-CINES (Grant
2019 AP010811227).
PY - 2020/8/19
Y1 - 2020/8/19
N2 - The widespread crisis of plastic pollution demands discovery of new and sustainable approaches to degrade robust plastics such as nylons. Using a green and sustainable approach based on hydrogenation, in the presence of a ruthenium pincer catalyst at 150 oC and 70 bar H2, we report here the first example of hydrogenative depolymerization of conventional, widely used nylons, and polyamides in general. Un-der the same catalytic conditions, we also demonstrate the hydrogenation of a polyurethane to produce diol, diamine and methanol. Additionally, we demonstrate an example where monomers (and oligomers) obtained from the hydrogenation process can be dehydrogenated back to a poly(oligo)amide of approximately similar molecular weight, thus completing a closed loop cycle for recycling of poly-amides. Based on the experimental and DFT studies, we propose a catalytic cycle for the process that is facilitated by metal-ligand cooperativity. Overall, this unprecedented transformation, albeit at the proof of concept level, offers a new approach towards a cleaner route to recycling nylons.
AB - The widespread crisis of plastic pollution demands discovery of new and sustainable approaches to degrade robust plastics such as nylons. Using a green and sustainable approach based on hydrogenation, in the presence of a ruthenium pincer catalyst at 150 oC and 70 bar H2, we report here the first example of hydrogenative depolymerization of conventional, widely used nylons, and polyamides in general. Un-der the same catalytic conditions, we also demonstrate the hydrogenation of a polyurethane to produce diol, diamine and methanol. Additionally, we demonstrate an example where monomers (and oligomers) obtained from the hydrogenation process can be dehydrogenated back to a poly(oligo)amide of approximately similar molecular weight, thus completing a closed loop cycle for recycling of poly-amides. Based on the experimental and DFT studies, we propose a catalytic cycle for the process that is facilitated by metal-ligand cooperativity. Overall, this unprecedented transformation, albeit at the proof of concept level, offers a new approach towards a cleaner route to recycling nylons.
U2 - 10.1021/jacs.0c05675
DO - 10.1021/jacs.0c05675
M3 - Article
SN - 0002-7863
VL - 142
SP - 14267
EP - 14275
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 33
ER -