LIQUID-PHASE HYDROGENATION OF CROTONALDEHYDE WITH SILVER MANGANESE CATALYSTS SUPPORTED ON AL2O3.5 AIPO

The liquid phase hydrogenation of crotonaldehyde has been investigated with silver and silver-manganese catalysts supported on alumina·aluminium phosphate. The relationship between catalytic activity and selectivity to trans-2-buten-1-ol was examined. Catalysts were prepared from metal nitrates by the impregnation method. Reaction was carried out at 130~210°C and 10~70 atm of hydrogen with a 10 vol% crotonaldehyde-hexane solution and 1.0 g of a catalyst in a 300 ml autoclave. With an increase in the P/Al atomic ratio in the catalyst support, dehydrogenation of 2-buten-1-ol to crotonaldehyde becomes prominent, leading to a decrease in apparent conversion. The selectivity is kept constant in the range of P/Al=0~0.8, and decrease at P/Al=1.0 where a crystalline Ag3PO4 is formed. Manganese added to silver catalyst as a promoter was found to increase both activity and selectivity of the catalyst. When the atomic ratio of manganese to silver was 1, 5 or above, the yield of 2-buten-1-ol was 70.5 mol%, whereas it is only 36.6 mol% over the catalyst without manganese addition. © 1990, The Chemical Society of Japan. All rights reserved.