Studies Of Hydrogenation Reaction Kinetics Of α, β-Unsaturated Aldehydes And Ketones Over Amorphous Alloy NiB

The author has studied the kinetics of hydrogenation of a,β-unsaturated aldehydes andketones such as cinnamaldehyde and 2-butylene cyclopentanone,β-ionone over amorphousalloy NiB catalyst at atmospheric pressure of H2 as well as effects of reaction conditions onthe kinetics.The reaction order is 1 relative to the substrate concentration, and-in the 20-60℃range,with the rise of temperature, the reaction rate constants k are increased, but continue toincrease the reaction temperature, decline, even no hydrogenation taking place. Solventaffects the selective hydrogenation of cinnamaldehyde on the hydrogenation reaction rate andproduct distribution. Among the three of absolute ethanol cyclohexane and tulene, in theinitial reaction C=C double bond is selectively hydrogenated; and in toluene reactiontemperature impact on the reaction rate constant little with the C=C double bond selectivity,best; in absolute ethanol the reaction rate constant at 60℃maximum with C=C double bondselectivity better; in cyclohexane, 40℃fastest rate, C=C double bond of selectivity underthe same conditions lowest in the three. The loading of catalyst is proportional to reactionspeed with litt-te effect on product distribution. And square of substrate concentration isinversely proportional to reaction rate constants k.In this paper, amorphous alloy catalyst NiB is compared with notable metal catalysts Pd/C(5ï¼…) and Ru/Al₂O₃ (5ï¼…) for hydrogenation of 13-ionone under atmospheric pressure, andamorphous alloy NiB displays moderate catalytic activity and selectivity toβ-dihydro-iononemore than 98ï¼…, whenβ-ionorie completely disappeared.And the author has calculated the apparent activation energy of the hydrogenation reactionEa based on Arrhenius formula. According to the kinetic data, the reaction mechanism isinferred simply.