N Restructuring of Iron-Based Catalysts Boosting the Formation of C<sub>2+</sub> Olefins from CO<sub>2</sub> Hydrogenation
Zhenzhou Zhang, Lingyu Jia, Yanjia Guo, Yuqiong Li, Feixue Han, Bingbing Liao, Shanshan Dang, Fei Chen, Weifeng Tu, Xiaohu Yu, Yi‐Fan Han
Abstract
The electronic structure of the active centers of an iron-based catalyst can be modulated by neighboring N atoms in the hydrogenation of CO 2 . This work provides mechanistic insights into the relationship between the Fe 4 N active centers and carbon chain growth pathways. The Na/Fe 4 N catalyst exhibits higher selectivity toward CO and C 2+ olefins with a higher olefin-to-paraffin (O/P) ratio and lower selectivity toward CH 4 . Through combined experimental evidence and theoretical calculations, we establish that the carbide-mediated pathway is more favored than the CO insertion mechanism on both the Fe 4 N and Fe 5 C 2 catalysts. Furthermore, the energy barrier for C–C coupling on the Na/Fe 4 N(110) surface (0.62 eV) is lower than that on Na/Fe 5 C 2 (11–2) (0.98 eV). Comparative analysis reveals that Na/Fe 4 N has weaker hydrogenation capability compared to Na/Fe 5 C 2 while possessing more CH x intermediates and nondissociatively adsorbed CO species. These fundamental insights into enhancing C–C coupling in iron-based catalytic systems are expected to offer guidance for the rational design of high-performance catalysts for CO 2 utilization.