Comparison of normal and reverse precipitation methods in the preparation of Cu/ZnO/Al₂O₃ catalysts for hydrogenolysis of butyl butyrate

For the hydrogenolysis of butyl butyrate into butanol, Cu/ZnO/Al ₂O₃ catalysts are prepared using normal precipitation (NP) and reverse precipitation (RP) methods. The activity trends of NP-series and RP-series catalysts are different as a function of the Cu/Zn ratio. Through several characterization techniques, the major differences between both series of catalyst samples are caused by the high-temperature carbonate (HT-CO ₃) present in the precursor phase. The butanol productivity of RP-series catalysts is thus found to be associated with the HT-CO₃ amount in precursor and calcined samples, while it shows a linear relationship with the copper surface area.