Study on the performance of F-T component modified KCuZrO₂ catalyst for CO hydrogenation to isobutanol

KCuZrO₂ catalysts modified with different F-T elements (Fe, Co, Ni) were prepared by co-precipitation method and then were tested for isobutanol synthesis from catalytic CO hydrogenation. The catalysts were characterized by N₂ adsorption and desorption experiments (BET), XRD, TEM, XPS, H₂-TPR, CO-TPD and in situ DRIFTS. The results showed that the addition of F-T components promoted the formation of ethanol and propanol, and had different effects on the selectivity of isobutanol. The characterization results showed that Fe promoted the dispersion of catalyst components, and enriched the active component Cu on the catalyst surface, which improved the active adsorption of H₂ and CO. In addition, more C₁ species were formed on the KFeCuZrO₂ catalyst surface, and these C₁ species could further react with ethanol and propanol to produce isobutanol. However, the catalysts modified by Co and Ni lacked sufficient C₁ species, so the selectivity of isobutanol did not increase significantly. The introduction of Co had little effect on the structure of catalyst and the dispersion of Cu, but the activity of catalyst decreased after Co addition, which might be due to the deactivation of catalyst. After adding Ni to the catalyst, the specific surface area decreased and the particle size increased, and the Cu/Zr molar ratio on the catalyst surface also decreased to 0.19. The interaction between Cu-Zr was weakened, and the isobutanol selectivity was also reduced.