Promotional effect of external magnetic field in FexOy/ZSM-5 for selective CO2 hydrogenation to C2-C4 and aromatic hydrocarbons

This study employed confined-space ZSM-5 zeolite in conjunction with an external magnetic field to manipulate iron oxide phase transformations, thereby enhancing CO2 hydrogenation and the selective production of larger hydrocarbons. Phase transformations of iron oxide were controlled by varying reduction times (0.0-6.0 h) and magnetic flux intensities (0.0-27.7 mT). The FexOy/ZSM-5 zeolite catalyst, at 20.7 mT, exhibited a predominant Fe3O4 phase, achieving the highest CO2 conversion (28.1 %, or 3.3 times higher) and producing 14.4 times more C2-C4 hydrocarbons compared to catalysts without a magnetic field. The combined effects of confined-space ZSM-5 zeolite and the magnetic field simultaneously achieved control over reactant gas diffusion and facilitated formation of Fe3O4 and FeO phases. Olefins, formed via the reverse water-gas shift reaction, underwent chain growth reactions through Fischer-Tropsch synthesis and aromatization within the ZSM-5 zeolite. This approach presents promising opportunities for environmentally friendly CO2 conversion.