Electronically Activated CuFeO₂ via Graphene Oxide for Highly Efficient CO₂ Conversion into Long-Chain Hydrocarbons

Utilizing CO2 as a feedstock to produce valuable chemicals and fuels provides a potential alternative to traditional methods reducing dependence on petroleum resources. It has been acknowledged that incorporating the reverse water gas shift (RWGS) and Fischer–Tropsch synthesis (FTS) active phase in a tandem system is crucial for optimizing the efficiency of CO2 hydrogenation. The formation of RWGS and FTS active phases in catalysts often involves creating an electron-rich local environment. In this study, graphene oxide (GO)-supported CuFeO2 was in situ synthesized under hydrothermal conditions (CuFeO2/GO-H), achieving an intimate interface and thus facilitating the electron transfer from GO to CuFeO2. The CuFeO2/GO-H exhibits a CO2 conversion of 36.8% and a C5+ selectivity of 66.0%, which are 1.6 and 1.4 times higher than those of pristine CuFeO2. The augmented CO2 hydrogenation performance of CuFeO2/GO-H is credited to the electron transfer facilitated by the cation−π interaction between CuFeO2 and surface oxygen-containing groups on GO. The electron transfer from GO to CuFeO2 not only boosts the adsorption of CO2 and CO but also promotes the reduction and carburization of CuFeO2 to form more small-sized Cu-χ-Fe5C2 active sites. In addition, the layer structure of GO with certain defects ensures a close proximity between the supported active phases, facilitating the formation of small-sized Cu and χ-Fe5C2 nanoparticles, as well as the exposure of Cu-χ-Fe5C2 interfaces. The small particle size and well-integrated Cu and χ-Fe5C2 in CuFeO2/GO-H enhance its CO2 conversion and C5+ selectivity by providing more active sites and reducing the kinetic barriers for C–C coupling. This study aligns with efforts to design bifunctional catalysts by emphasizing the electron transfer process in optimizing the rate of CO2 hydrogenation.