Synthesis Of 2-pentanone Via Guerbet Reaction Over Ni-Fe Bimetallic Catalyst

In this paper,2-pentanone（2-PE）was prepared by selective condensation hydrogenation of ethanol and acetone through Guerbet reaction.The effect of Ni/AC supported on activated carbon on the reaction was systematically studied.Non noble bimetallic Ni-Fe catalyst was prepared by introducing Fe into Ni based catalyst,the catalytic performance of these catalysts for the synthesis of 2-pentanone from ethanol and acetone by Guerbet reaction was investigated.The relationship between the structure and catalytic performance of Ni-Fe Bimetallic Catalysts was investigated by various characterization methods.The main conclusions are as follows.（1）The test results showed that at 448 K,the selectivity of 2-PE decreased and a large number of by-products appeared due to the high activity of Ni catalyst;On the bimetallic Ni-Fe/AC catalyst,the selectivity of 2-PE first increases and then decreases with the increase of Fe content;When Ni/Fe=5（i.e.Ni₅-Fe₁/AC）,the catalytic performance is the best,and the selectivity of 2-PE reaches 56.3%.The 2-PE selectivity over Ni₅-Fe₁/AC catalyst decreased to29.3%when the reaction temperature was reduced to 373 K and other conditions remained unchanged.It can be seen that the selectivity of the target product was significantly affected by the reaction temperature.After five times of usage,the conversion of ethanol and acetone remained about 77%,but the selectivity of 2-PE gradually decreased from 56.3%to 49.2%;The selectivity of 2-PE can be recovered by calcining and reducing the catalyst after the fifth recycle.In addition,the magnetic catalyst can be recovered by magnetic separation.（2）The results of XRD,ICP-AES and TGA show that there is no obvious change of Ni particles before and after the reaction,and there is no loss of Ni and Fe.It is speculated that the deactivation of the catalyst is caused by the covering of metal active sites by organic compounds produced during the reaction.The characterization results of H₂-TPR,XPS,XRD and SEM show that the dispersion of Ni nanoparticles can be improved by adding a certain amount of Fe,and it is conducive to the formation of a specific Ni-Fe alloy structure with Ni on AC surface during the reduction process.The difference of activity and selectivity between single metal Ni/AC catalyst and bimetallic Ni-Fe/AC catalyst is closely related to the formation of Ni Fe alloy structure.