Selective hydrogenation of unsaturated aldehyde in gas-liquid-liquid-solidfour phases

Cinnamaldehyde (one kind of unsaturated aldehydes) was hydrogenated to hydr ocinnamaldehyde (one kind of saturated aldehydes), cinnamyl alcohol (one ki nd of unsaturated alcohols) and hydrocinnamyl alcohol (one kind of saturate d alcohols). Gas (hydrogen)-liquid (organic solution, reactant and products )-liquid (alkaline aqueous solution)-solid (catalyst) four phases existed i n a batch reactor. The selectivity was significantly varied by two kinds of catalysts. Reaction kinetics were studied by using Pd/C or Pt/C as a catal yst. When Pd/C was used, hydrocinnamaldehyde was the main product and the f ormation rate was 0.012 mol/(s kg-cat). When Pt/C was used, cinnamyl alcoho l was the main product and the formation rate was 0.0013 mol/(s kg-cat). (C ) 1999 Elsevier Science Ltd. All rights reserved.