Kinetics of Liquid-phase Hydrogenation of Aliphatic α,β-Unsaturated Aldehyde over Raney Cobalt Catalyst Modified with Co-, Mn-, Ni-, and PdCl<SUB>2</SUB>
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概要
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Kinetic studies were carried out on the hydrogenation of the α,β-unsaturated aldehyde, 2-methyl-2-pentenal (UD), over the Raney cobalt catalyst modified with various amounts of Co-, Mn-, Ni- and PdCl<SUB>2</SUB> in <I>n</I>-hexane under atmospheric pressure at 40 and 20°C. Initial rates of formation of the saturated aldehyde (<I>r</I><SUB>SD</SUB>), saturated alcohol(<I>r</I><SUB>SA</SUB>) and unsaturated alcohol(<I>r</I><SUB>UA</SUB>) were determined in the concentration range of UD((<I>C</I><SUB>UD</SUB>) 0.018–0.263 mol/<I>l</I>. It was found that (<I>r</I><SUB>SD</SUB>+<I>r</I><SUB>SA</SUB>) obeyed a Langmuir-type rate equation and <I>r</I><SUB>UA</SUB> a different one. The rate equations are as follows.<BR><I>r</I><SUB>SD</SUB>+<I>r</I><SUB>SA</SUB>=\frac<I>k</I><SUB>1</SUB>·<I>b</I><SUB>1</SUB>·<I>C</I><SUB>UD</SUB>(1+<I>b</I><SUB>1</SUB>·<I>C</I><SUB>UD</SUB>)<SUP>2</SUP>, <I>r</I><SUB>UA</SUB>=\frac<I>k</I><SUB>2</SUB>·<I>b</I><SUB>2</SUB>·<I>C</I><SUB>UD</SUB>(1+<I>b</I><SUB>2</SUB>·<I>C</I><SUB>UD</SUB>)<SUP>2</SUP><BR>where <I>k</I> and <I>b</I> denote the rate constant of the surface reaction and parameter for the adsorption of UD and hydrogen, respectively, the subscripts 1 and 2 representing the formation of SA and SD and that of UA, respectively. Kinetic parameters <I>k</I><SUB>1</SUB>, <I>k</I><SUB>2</SUB>, <I>b</I><SUB>1</SUB> and <I>b</I><SUB>2</SUB> were found to vary with the amount and kind of modifier. The variation of <I>b</I><SUB>1</SUB> and <I>b</I><SUB>2</SUB> was irregular. The rate constant <I>k</I><SUB>1</SUB> decreased with increasing amount of Co-, Mn- and NiCl<SUB>2</SUB> added; it increased remarkably with the addition of PdCl<SUB>2</SUB>. The variation of <I>k</I><SUB>2</SUB> was more complicated. Addition of a small amount of the modifiers did not decrease <I>k</I><SUB>2</SUB>. Further addition of Co- and MnCl<SUB>2</SUB> made <I>k</I><SUB>2</SUB> decrease, while that of NiCl<SUB>2</SUB> made it increase. Mechanism of the modification with these metal chlorides is discussed on the basis of the active site hypothesis.
- 公益社団法人 日本化学会の論文
著者
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Hotta Kazuhiko
The Osaka Municipal Technical Research Institute
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Kubomatsu Teruo
The Osaka Municipal Technical Research Institute
関連論文
- Kinetics of Liquid-phase Hydrogenation of Aliphatic α,β-Unsaturated Aldehyde over Raney Cobalt Catalyst
- Kinetics of Liquid-phase Hydrogenation of Aliphatic α,β-Unsaturated Aldehyde over Raney Cobalt Catalyst Modified with Co-, Mn-, Ni-, and PdCl2
- Modifying Effect of Acetic Acid or Triphenylphosphine on the Raney Cobalt Catalyst in the Liquid-phase Hydrogenation of an Aliphatic α,β-Unsaturated Aldehyde