2022/03/23 by Sewon Oh, Erin E. Stache · 1 citation
Chemistry · Energy · #Radical Photochemical Reactions #Advanced Photocatalysis Techniques #Advanced Polymer Synthesis and Characterization #Polystyrene #Chemistry #Catalysis #Benzoic acid #Radical #Polymer #Homolysis #Photochemistry #Polymer chemistry #Hydrogen atom abstraction #Chlorine #Degradation (telecommunications) #Organic chemistry
paper · doi:10.1021/jacs.2c01411
openalex publication_date 2022/03/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Chemical upcycling of polystyrene into targeted small molecules is desirable to reduce plastic pollution. Herein, we report the upcycling of polystyrene to benzoyl products, primarily benzoic acid, using a catalyst-controlled photooxidative degradation method. FeCl 3 undergoes a homolytic cleavage upon irradiation with white light to generate a chlorine radical, abstracting an electron-rich hydrogen atom on the polymer backbone. Under the oxygen-rich environment, high MW polystyrene (>90 kg/mol) degrades down to <1 kg/mol and produces up to 23 mol % benzoyl products. A series of mechanistic studies showed that chlorine radicals promoted the degradation via hydrogen-atom abstraction. Commercial polystyrene degrades efficiently in our method, showing the compatibility of our system with polymer fillers. Finally, we demonstrated the potential of scaling up our approach in a photoflow process to convert gram quantities of PS to benzoic acid.