Friday, 11 July 2025 11:00am – 12:00pm

This seminar will be delivered in Edward Ford Building – Norman Gregg Lecture Theatre

Speaker: Dr Tatchamapan Yoskamtorn

Host: Dr Marcello Solomon

Title: Selective Production of C3 Hydrocarbons from Thermoplastic Blends via Tandem Heterogeneous Catalysis

Abstract
Chemical recycling of thermoplastics via selective cleavage of the plastics to monomers under mild conditions to build a closed-loop polymer recycling remains a significant challenge, especially for polyolefin (PO), including polyethylene (PE) and polypropylene (PP), due to their strong carbon-carbon bonds. This study presents a novel chemical recycling strategy for the selective conversion of PO polymers blended initially with polystyrene (PS) into C3 hydrocarbons using tandem solid catalysts composed of MFI zeolite and Al₂O₃-supported metal nanoparticles. Conducted at 330°C and 30 bar H₂ for 10 hours, the reaction achieves up to 66 wt% mass yield of C3 gaseous products without noticeable deactivation. It is evident that the in-situ generation of multisubstituted aromatics during depolymerisation induces autocatalytic hydrocarbon pool chemistry, enhancing C3 hydrocarbon production while suppressing coke formation. Notably, the reaction proceeds continuously upon successive PO additions without the need for additional PS attributed to residual multisubstituted aromatics in the liquid phase after each reaction cycle. This high selectivity toward C3 hydrocarbons from chemically inert and non-biodegradable thermoplastics offers a feasible pathway for the regeneration of propylene monomers through propane dehydrogenation or ethylene monomers via cracking, hence enabling closed-loop recycled polymerisation.

One-Sentence Summary: The in-situ generation of multisubstituted aromatic compounds via catalytic chemical recycling of polystyrene-polyolefin blends using tandem heterogeneous catalysis facilitates selective C3 hydrocarbon production.

Bio
Since February 2024, Dr Tatchamapan Yoskamtorn has held the position of lecturer in Inorganic Chemistry at the Department of Chemistry, Faculty of Science, Chulalongkorn University. After completing her DPhil in Inorganic Chemistry under Professor Edman Tsang at the University of Oxford in 2021, she worked as a postdoctoral researcher at the SCG-Oxford Centre of Excellence in Chemistry, where she studied the chemical recycling of thermoplastic wastes into value-added products. Her current research centres on green and sustainable chemistry, specifically the design and development of multifunctional materials such as metal-organic frameworks, zeolites, and metal oxides, for applications in waste-to-fuel and waste-to-energy catalysis. To fully understand the interplay between structure, dynamics, and activity in these materials, advanced integrated techniques such as synchrotron and neutron diffraction, neutron scattering, and Rietveld refinement have been applied extensively in her studies.