Preparation And Performance Of Amorphous Alloy Catalyst For Hydroquinone Hydrogenation

1,4-cyclohexanediol is an important chemical material and chemical intermediate.1,4-cyclohexanediol is widely used in organic synthesis,fine chemicals and other fields.In the process for preparing 1,4-cyclohexanediol by hydroquinone hydrogenation,due to low price of hydroquinone,the product 1,4-cyclohexanediol has high economic benefits,so it is very important to study this technological process.In this paper,the ?-Al₂O₃ was used as carrier for preparing binary and ternary supported amorphous alloy catalysts.Morphology,structure,particle size and dispersion of two catalyst were analyzed and compared through the use of characterization methods of XRD,TEM,BET and TGA in this paper.The results show that the two catalysts form amorphous alloy structure.By strictly controlling the reaction conditions during the preparation process,which makes the active components are less likely to agglomerate,and the ternary components improve the catalytic activity center by synergistic effect.The ternary components are tested to have excellent catalytic activity compared to the binary component.With the ?-Al₂O₃ as the carrier,the Ru as the active element,by taking catalytic hydrogenation of hydroquinone as reaction experiment,this paper not only explores the effects of the additives W but also investigat the effect of each reaction condition on reactant conversion and the selectivity of the target product,comparing and analyzing the optimal reaction conditions under these two kinds of catalytic system.The results show that the addition of W has a significant effect on the catalytic performance.Under the action of NaBH₄,a small amount of WO₃ particles is formed on the surface of the catalyst.The proper amount of WO₃ acts as the center of catalyst Br?nsted acid,which can improve the reactivity of the catalyst.And the atomic radius of the W element is slightly larger than the atomic radius of the Ru element,which contributes to the uniform dispersion of the active element Ru at the appropriate Ru: W.The catalyst is prepared by chemical reduction method,the main component is amorphous ruthenium boron alloy,which has high catalytic activity.The optimal reaction conditions for the experiment of ternary catalyst are as followings: reaction time is 3 h,reaction temperature is 130 ?,hydrogen pressure is 3 MPa and Ru:W=3:1,under these conditions,the hydroquinone conversion is 100 %,and the 1,4-cyclohexanediol selectivity is 96.53 %.The optimal reaction conditions for the experiment of binary catalyst are as followings: reaction time is 3.5 h,reaction temperature is 140 ?,hydrogen pressure is 3 MPa and the load of Ru is 1.0 %,under these conditions,the hydroquinone conversion is 86.23 %,and the 1,4-cyclohexanediol selectivity is 86.53 %.The hydrogenation reaction path of the probe experiment was analyzed by continuously detecting the distribution of products at different reaction times.