Constructing stable Cu-Fe5C2 interfaces for efficient syngas conversion to higher alcohols

Direct and efficient synthesis of higher alcohols (HA) from syngas over Cu-Fe binary catalysts is promising, but remaining big challenge due to the complex reaction networks and poor stability of Cu-Fe₅C₂ interfaces. Herein, we constructed a K-CuFe@SiO₂ core–shell catalyst, which showed high HA selectivity of 51.1 %, HA yield of 14.6 % and low CO₂ selectivity of 15.3 % at a mild reaction temperature of 240 °C, outperforming most of the reported advanced Cu-Fe binary catalysts. Structural characterizations confirmed that SiO₂ shell played critical role in stabilizing Cu-Fe₅C₂ interfaces during long-term operation. Moreover, SiO₂ shell could regulate the electronic interactions between K promoter and active phases, and then regulating the H₂ and CO activations. Mechanism studies suggested that HA synthesis followed *CO–*CH_x coupling mechanism. The balance of H₂ activation, CO dissociated and non-dissociated activation was critical to realize the dynamic matching of *CO–*CH_x coupling and *CH₃CO hydrogenation reactions, thus maximizing HAS activity.