The activation of reactant molecules on catalyst surface plays critical roles in the catalytic reaction process. The activation of CO₂ and H₂ molecules on clean and K₂O-adsorbed Fe₅C₂(110) were comparatively investigated via density functional theory (DFT) calculations to disclose the promoting effect of K₂O on hydrogenation of CO₂ to olefins. DFT calculations suggest that the adsorption of K₂O helps to direct activation of CO₂ to CO species, and then promote in-situ CC* coupling of CO with surface carbon of χ-Fe₅C₂. The Fe-H bond from H₂ dissociation on K₂O-adsorbed Fe₅C₂(110) can lower the activity of H species, by which helps to avoid the over-hydrogenation of olefins to saturated alkanes. This study partially reveals the promoting effect of K₂O on the activation of reactant molecules on χ-Fe₅C₂ surface, which is helpful to design new catalysts for CO₂ conversion to value-added chemicals.

催化剂表面反应物分子的活化在催化反应过程中起着至关重要的作用。通过密度泛函理论(DFT)计算对比研究了CO ₂和H ₂分子在清洁和K ₂ O吸附的Fe ₅ C ₂ (110)上的活化作用，揭示了K ₂ O对CO ₂加氢生成的促进作用。烯烃。DFT计算表明，K ₂ O的吸附有助于将CO ₂直接活化为CO物种，进而促进CO与χ-Fe ₅ C _{2表面碳的}原位C C*偶联. K ₂ O吸附的Fe ₅ C _{2 (110)上的H 2}解离产生的Fe-H键可以降低H物种的活性，这有助于避免烯烃过度氢化成饱和烷烃。本研究部分揭示了K ₂ O对χ-Fe ₅ C ₂表面反应物分子活化的促进作用，有助于设计用于CO ₂转化为增值化学品的新型催化剂。