Higher alcohols synthesis via CO hydrogenation on Cu/Zn/Al/Zr catalysts without alkalis and F–T elements

Abstract

A series of Cu/Zn/Al/Zr catalysts without alkalis and F–T elements, were prepared with various atomic ratios of Al/Zr by complete liquid-phase technology and tested for higher alcohols synthesis from CO hydrogenation. The results showed that the Cu/Zn/Al catalyst exhibited excellent higher alcohols selectivity, reaching approximately 58.8%. With the increase of Zr/Al atomic ratio, the catalytic activity and stability increased, but methanol became the dominant product in the liquid products over Cu/Zn/Zr catalyst. It was concluded that Al favored the formation of higher alcohols and Zr was beneficial to improve the stability of catalysts. Characterization results showed that the addition of Zr improved the dispersion of Cu and made the catalyst easier to be reduced. It also favored the stability of pore structure and decreased the amount of weak acidic sites. It was also found that the amount of the weak acidic sites played a key role in the higher alcohols formation and the amount of weak acidic sites decrease might lead to the deactivation of catalysts.