Dehydrogenative aromatization of 1-octene over multifunctional Ni/ZSM-5-P-Fe catalyst

Abstract 1-octene is used as a model compound to investigate its dehydrogenative aromatization over a series of Ni/ZSM-5-based catalysts. It is shown that the Ni/ZSM-5-P-Fe presents convincing catalytic performance on the 1-octene conversion and aromatics selectivity with satisfactory durability and little coking. Evidenced by characterization results, the modification of P, Fe and Ni on ZSM-5, 1) reduces both concentration and strength of Bronsted acid sites, 2) generates the new Lewis acid sites which are much stronger than the common extra-framework Al, and 3) provides adequate metallic site. Above features correlate well with the reaction results. Supported by the DFT calculation, the cyclization of octene is achieved from the interaction with both BAS and LAS. After a sequence of carboncation shifts, following the 5-membered ring expansion and the dimethylcyclohexane dehydrogenation, the aromatic product is finally formed.