Tandem Electrocatalytic–Thermocatalytic Conversion of CO₂ to Aromatic Hydrocarbons

The reaction of CO2 with H2O to produce aromatic hydrocarbons (benzene, toluene, ethylbenzene, and xylene isomers) (BTEX) represents a promising pathway for converting CO2 to value-added liquid products. However, this reaction cannot be achieved in a single electrochemical or thermochemical process. This work utilizes tandem electrochemical–thermochemical reactors as a new paradigm by starting with CO2 and H2O as the feed in a membrane electrode assembly (MEA) to produce C2H4, which subsequently undergoes thermochemical aromatization using a gallium- and phosphorus-modified zeolite ZSM-5 catalyst (Ga/ZSM-5/P) at ambient pressure to produce BTEX. The current study also demonstrates the potential advantage of the tandem strategy in mitigating negative effects of water by testing the tandem reactor system under different hydration conditions and by performing in situ X-ray diffraction (XRD) and X-ray absorption (XAS) characterization of the aromatization catalysts. These results highlight the advantage of using the tandem process with the use of a water trap before the thermochemical reactor.