Upcycling CO2 and bio-derived furan into degradable plastic monomer via coupling of photocatalysis and thermocatalysis

Coupling of CO₂ with biomass-derived molecules into degradable plastic monomer provides a promising strategy to address the increasing problems of carbon recycle and carbon neutrality. Herein, we develop a sustainable route to produce 6-hydroxycaproate (6-HMC) by coupling photocatalytic carboxylation of biomass-derived furfuryl alcohol with CO₂ to 2-furanacetic acid (FA), and the thermocatalytic hydrogenolysis of methyl 2-tetrahydrofuranyl acetate (MTFA) derived from FA, wherein Pd/CeO₂ exhibit the highest productivity of 6-HMC (505 mmol_6-HMC mmol^-1_metal h⁻¹), much higher than its counterparts of precious- and non-precious-metal catalysts. Moreover, Pd/CeO₂ also presents good stability for 6 recycles without remarkable decrease in 6-HMC yield. Systematic experiments and computational studies suggest that higher concentration of oxygen vacancies and strong metal-support interactions account for enhanced catalytic performance of Pd/CeO₂. The work employs CO₂ and lignocellulosic-derived platform molecule as feedstocks to produce valuable degradable plastic monomer, providing a promising route to access pure-CO₂ originated high-carbon oxygen-containing compounds.