Liquid-Phase Hydrogenation of Crotonaldehyde with Silver-Manganese Mixed Oxide Catalysts

Abstract

The liquid-phase hydrogenation of crotonaldehyde has been investigated with silver-manganese mixed oxide catalyst. Relationships between activity, 2-buten-1-ol selectivity and crystal states of catalysts calcined at different temperatures were examined. The catalyst calcined at 500 °C had a high conversion of 85.1% and 2-buten-1-ol selectivity of 71.8%. The catalyst was prepared from a mixed solution of silver nitrate and manganese nitrate and an aqueous solution of sodium hydroxide by coprecipitation method. The active catalyst is mainly composed of amorphous Ag₂O, amorphous MnO_, and a crystalline γ-Mn₂O₃. The effects of manganese oxide in the catalyst are to inhibit the reduction of amorphous silver oxide to silver crystal at low temperature, and to cause an increase in the concentration of active silver in the catalyst surface, which probably lead to a high activity and a high selectivity of the catalyst.