Synergistic Effect of Pt and FeCo Alloy Carbide in Promoting Higher Alcohol Synthesis from Syngas

Higher alcohol synthesis (HAS) from syngas with high activity and selectivity is of great interest but presents significant challenges due to the competition between CO dissociative adsorption and nondissociative adsorption. Herein, the Pt promoter was introduced to the CoFe alloy carbide to act as an additional site for CO nondissociative adsorption to promote the insertion of CO to generate oxygenates. Over the 0.43Pt–CoFe alloy carbide catalyst, 69.1% CO conversion and 41.9% oxygenate selectivity were achieved, with the productivity of C2+OH approximately 2.5 fold higher than that of the Pt-free CoFe alloy carbide counterpart. Studies proved that Pt was highly dispersed on the CoFe alloy carbide, and the addition of Pt not only promoted the reduction and carburization of CoFe-based catalysts but also boosted the CO adsorption ability. C3H6-pulse, in situ DRIFTS, and hydroformylation probe experiments further confirmed that the existence of Pt sites could weaken hydrogenation ability and simultaneously strengthen the coupling of CO*-containing species with alkyl species to form oxygenated products at the interfacial sites of Pt and (FexCoy)2C. The synergistic effect of multifunctional sites, including Pt and CoFe alloy carbide, contributes greatly to the enhanced performance in higher alcohol synthesis.