Rapid Microwave Construction of Interfacial Active Sites: Deciphering Support Effects in CO <b> ₂ </b> Hydrogenation to Light Olefins

Converting CO2 into value-added light olefins offers a promising pathway for carbon neutrality, yet developing robust catalysts that operate efficiently under mild conditions remains a formidable challenge. In this study, we demonstrate a rapid microwave-assisted strategy to tailor the metal–support interactions of Na–Fe–Zn species across varying support architectures (CeO2, Al2O3, and CNTs). A systematic investigation reveals that the support identity plays a decisive role in catalytic performance. Among the candidates, the CeO2-supported catalyst emerges as the superior system, delivering a remarkable CO2 conversion of ∼53% and a light olefin selectivity of ∼55% under mild reaction conditions (300 °C, 1.5 MPa). Characterization via XRD, H2-TPR, and in situ Raman spectroscopy uncovers the mechanistic origin of this enhancement: microwave irradiation facilitates the generation of abundant surface oxygen vacancies. These structural features promote the reducibility of iron species and the in situ evolution of the active Fe5C2 carbide phase, significantly surpassing the performance of Al2O3- and CNT-supported counterparts. This work not only presents a highly efficient catalyst for CO2 valorization but also highlights the potential of microwave-driven defect engineering in unlocking synergistic catalytic effects.