Ethylene oligomerization over mesoporous FeNi-BTC catalysts: Effect of the textural properties of the catalyst on the reaction performance

Abstract

Mesoporous FeNi-1,3,5-benzenetricarboxylates (FeNi-BTCs) with different Fe/Ni ratios were prepared, and their catalytic activities in ethylene oligomerization were evaluated. The textural properties of the bimetallic FeNi-BTC were considerably affected by the Fe/Ni ratio, exhibiting a volcano relationship, with the maximum specific surface area, pore volume, and diameter observed at Fe/Ni = 10/90. The enhanced textural properties of the FeNi-BTC catalyst resulted in accelerated ethylene oligomerization and an increased C6–C8 oligomer selectivity. Using the Fe10Ni90-BTC catalyst, the rate of ethylene consumption and C6–C8 oligomer selectivity reached as high as 2823 g C2H4/g Ni h and 49%, which were approximately four- and two-fold higher than those of Ni-BTC, respectively. The remarkable reaction performance of the Fe10Ni90-BTC catalyst could be rationalized in terms of its well-defined mesoporous structure, which could decrease the mass transfer resistance and thereby facilitate intrapore ethylene diffusion during ethylene oligomerization. These results clearly demonstrate the potential of the FeNi-BTC catalyst in promoting ethylene oligomerization with a high activity and selectivity towards C6∼C8 oligomers. In the catalyst recycling study, whereas the catalytic activity decreased due to the partial deformation of the FeNi-BTC catalyst with repeated recycling, the selectivity towards C6+ oligomers gradually increased.