Valorisation of plastic waste via metal-catalysed depolymerisation
- Francesca Liguori,
- Carmen Moreno-Marrodán and
- Pierluigi Barbaro
Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53
Graphical Abstract
Figure 1: Potential classification of plastic recycling processes. The area covered by the present review is ...
Figure 2: EG produced during glycolytic depolymerisation of PET using DEG + DPG as solvent and titanium(IV) n...
Scheme 1: Simplified representation of the conversion of 1,4-PBD to C16–C44 macrocycles using Ru metathesis c...
Figure 3: Main added-value monomers obtainable by catalytic depolymerisation of PET via chemolytic methods.
Scheme 2: Hydrogenolytic depolymerisation of PET by ruthenium complexes.
Scheme 3: Depolymerisation of PET via catalytic hydrosilylation by Ir(III) pincer complex.
Scheme 4: Catalytic hydrolysis (top) and methanolysis (bottom) reactions of PET.
Scheme 5: Depolymerisation of PET by glycolysis with ethylene glycol.
Figure 4: Glycolysis of PET: evolution of BHET yield over time, with and without zinc acetate catalyst (196 °...
Scheme 6: Potential activated complex for the glycolysis reaction of PET catalysed by metallated ILs and evol...
Scheme 7: One-pot, two-step process for PET repurposing via chemical recycling.
Scheme 8: Synthetic routes to PLA.
Scheme 9: Structures of the zinc molecular catalysts used for PLA-methanolysis in various works. a) See [265], b) ...
Scheme 10: Depolymerisation of PLLA by Zn–N-heterocyclic carbene complex.
Scheme 11: Salalen ligands.
Scheme 12: Catalytic hydrogenolysis of PLA.
Scheme 13: Catalytic hydrosilylation of PLA.
Scheme 14: Hydrogenative depolymerisation of PBT and PCL by molecular Ru catalysts.
Scheme 15: Glycolysis reaction of PCT by diethylene glycol.
Scheme 16: Polymerisation–depolymerisation cycle of 3,4-T6GBL.
Scheme 17: Polymerisation–depolymerisation cycle of 2,3-HDB.
Scheme 18: Hydrogenative depolymerisation of PBPAC by molecular Ru catalysts.
Scheme 19: Catalytic hydrolysis (top), alcoholysis (middle) and aminolysis (bottom) reactions of PBPAC.
Scheme 20: Hydrogenative depolymerisation of PPC (top) and PEC (bottom) by molecular Ru catalysts.
Scheme 21: Polymerisation-depolymerisation cycle of BEP.
Scheme 22: Hydrogenolysis of polyamides using soluble Ru catalysts.
Scheme 23: Catalytic depolymerisation of epoxy resin/carbon fibres composite.
Scheme 24: Depolymerisation of polyethers with metal salt catalysts and acyl chlorides.
Scheme 25: Proposed mechanism for the iron-catalysed depolymerisation reaction of polyethers. Adapted with per...
Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes
- Carmen Moreno-Marrodan,
- Francesca Liguori and
- Pierluigi Barbaro
Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73
Graphical Abstract
Scheme 1: Common reaction pathways for alkyne hydrogenation reactions.
Figure 1: Schematic representation of most common reactor types for batch and continuous-flow partial hydroge...
Figure 2: Schematic representation of flow regimes in microchannels; (a) bubbly flow, (b) slug/Taylor or segm...
Figure 3: Sketch of typical continuous flow apparatus for liquid-phase catalytic alkynes hydrogenation reacti...
Scheme 2: Hydrogenation reactions of terminal alkynes with potential products and labelling scheme.
Figure 4: Structure of Pd@mpg-C3N4 (a), Pd(HHDMA)@C (b), Pd(Pb)@CaCO3 (c) and Pd@Al2O3 (d) catalysts. The str...
Figure 5: Sketch of composition (left) and optical image of Pd@MonoBor monolithic reactor (right). Adapted wi...
Figure 6: X-ray tomography 3D-reconstruction image of MonoBor [133]. Unpublished image from the authors.
Figure 7: Representative TEM image of titanate nanotubes with immobilized PdNP (arrows). Adapted with permiss...
Figure 8: Conversion and selectivity vs. time-on-stream for the continuous-flow hydrogenation of 6 over Pd@Mo...
Figure 9: Continuous-flow hydrogenation of 3, 6 and 7 over different catalytic reactor systems. Data from ref...
Scheme 3: Hydrogenation reactions of internal alkynes with potential products and labelling scheme.
Figure 10: Continuous-flow hydrogenation of 11 over Pd@MonoBor catalyst. a) Conversion and selectivity as a fu...
Figure 11: Conversion and selectivity vs time-on-stream for the continuous-flow hydrogenation of 11 over Pd@Mo...
Figure 12: Continuous-flow hydrogenation reaction of 11 over packed-bed catalysts. Adapted with permission fro...
Figure 13: Images of the bimodal TiO2 monolith with well-defined macroporosity: (a, b) optical; (c) X-ray tomo...
Figure 14: Selectivity of the continuous-flow partial hydrogenation reaction of 3 and 4 over packed-bed Pd cat...
