Zhang, Ranqing; Xin, Jing; Zhang, Peipei; Mi, Xiaotong; Li, Sixuan; Zhou, Xuan; Gong, Kun; An, Yunlei; Lin, Tiejun; Zhong, Liangshu

ACS CATALYSIS

2025, 21,

Zhang, Ranqing; Xin, Jing; Zhang, Peipei; Mi, Xiaotong; Li, Sixuan; Zhou, Xuan; Gong, Kun; An, Yunlei; Lin, Tiejun; Zhong, Liangshu

Direct conversion of CO2-containing syngas into value-added olefins provides an effective route for the utilization of carbon-based resources. However, it remains a grand challenge to simultaneously achieve the coconversion of CO and CO2 due to the distinct activation behaviors of their C-O bonds. Herein, a K- and Zn-doped CoFe alloy carbide catalyst was prepared for the efficient conversion of CO2-rich syngas into olefins with negative carbon emission. The as-prepared CoFeZn catalyst, featuring (CoxFe1-x)(5)C-2 as the active phase, achieves 49.5% olefin selectivity at 98.0% CO and 16.7% CO2 conversions, with a high olefin space-time yield of 163.7 mgg(cat)(-1)h(-1) and stability of 110 h. Compared with traditional Fe-based catalytic systems that generate substantial CO2 byproducts, the Zn-(CoxFe1-x)(5)C-2 catalyst not only significantly inhibits CO2 formation but also converts CO2 into target olefins. Characterization results suggest that Co is uniformly doped into Fe5C2 to form (CoxFe1-x)(5)C-2, while the addition of Zn enhances H-2 dissociation and reverse water gas shift activity. The synergistic effect of Co, Fe, and Zn promotes the adsorption and activation of CO/CO2, where CO2 is converted to CO via the RWGS reaction, followed by the Fischer-Tropsch synthesis route to produce olefins. This work provides a promising strategy for designing efficient catalysts to coconvert CO and CO2, eliminating the need for CO2 removal in syngas processing.