Pathways to Aromatics in the Catalytic Pyrolysis of a Polyvinylchloride Model Compound Revealed by Operando Photoelectron Photoion Coincidence Spectroscopy

• DOI: 10.1002/cssc.202500516
• Publication Date: 2025-05-05T14:50:44Z
• Authors: Jovanni Cabana; Zihao Zhang; Zeyou Pan; Pawan Kumar; Xiangkun Wu; Andras Bodi; Gustavo A. Garcia; Yang Shen; Xintong Xiao; Hao Ma; Chen Huang; Chengyuan Liu; Long Zhao; Yang Pan; Zhongyue Zhou; Jeroen A. van Bok...; Patrick Hemberger
• Keywords: Propargyl

We reveal dechlorination channels and pathways to olefins aromatics in the catalytic pyrolysis of polyvinylchloride (PVC) model compound 1,3‐dichlorobutane by operando photoelectron photoion coincidence (PEPICO) spectroscopy. Experimental computational results agree that primary pathway involves double dehydrochlorination producing 1,3‐butadiene HCl. Minor radical are evidenced detection chloromethyl, methyl, propargyl radicals thermal decomposition, while chlorine absent. HZSM‐5 zeolites lower reaction temperature facilitate association reactions C5–C12 olefins. Further steps detected experimentally part isomer‐selectively, mimic previously postulated cross‐linking PVC pyrolysis. Our study identifies C–C coupling as well Diels–Alder dimerization butadiene yield polymethylated cyclopentadienes. These central precursors aromatics, e.g., benzene, toluene, xylenes (BTX). find ring expansion contraction transmethylation dominant routes aromatic products. The mechanisms during thermocatalytic conversion applicable other plastics resemble chemistry upon methanol methylchloride–to–hydrocarbons conversion, which will inspire new strategies enhance selectivity towards mitigate coke formation.