The anti-sintering catalysts: Fe–Co–Zr polymetallic fibers for CO₂ hydrogenation to C₂ = –C₄ = –rich hydrocarbons

Polymetallic fibers of 13Fe2Co/ZrO₂ and 13Fe2Co100Zr were prepared by impregnation and an in situ electrospinning technique. The iron, cobalt and zirconium components in the 13Fe2Co100Zr catalyst are more dispersed than the impregnation one, as indicated by SEM/EDS, TEM, XRD, H₂-TPR and N₂ adsorption techniques. CO₂ conversion increased by a factor of 2 and the selectivity to C₂⁺ hydrocarbons increased 15 times on the 13Fe2Co100Zr polymetallic fibers compared with the 13Fe2Co/ZrO₂ supported catalyst. The 0.18 s⁻¹ TOF (turnover frequency) of the polymetallic fibers exceeded that of the supported catalyst (0.12 s⁻¹). Potassium addition to the 13Fe2Co100Zr catalyst further improved the selectivity to C₂⁼–C₄⁼, which increased to 27.5% on a 10K13Fe2Co100Zr catalyst. The polymetallic fibers showed stable activity over the reaction period. The activity of the 13Fe2Co/ZrO₂ catalyst, however, decreased rapidly due to metal sintering as observed with TEM and XRD. The in situ electrospinning technique can effectively prevent metal sintering and provide high CO₂ conversion efficiency.