Modulating acid site spatial location of Zn/ZSM‐5 catalyst to boost the stable aromatization of hexane

Abstract Engineering acid site spatial location of zeolite catalyst harbors tremendous potential to boost catalytic performance but still remains a grand challenge for aromatization reaction. Herein, we successfully manipulate acid site spatial location inside the ZSM‐5 channels to promote the hexane aromatization via the simple SiO 2 coating treatment. Multi‐techniques demonstrated that the medium strong L acid in the channel originated from the Si(Al)OZn structure is mainly retained in the Zn/ZSM‐5‐Si catalyst by covering the acid sites outside the channel. Surprisingly, there is a good linear relationship between BTEX yield and this medium strong L acid content. Based on the reaction kinetics, in situ FT‐IR and theoretical calculations, it is found that the L acid with confinement effect served as the main active site could prominently enhance the cyclization of propene intermediate and the dehydrogenation of cycloalkane due to the strong affinity between the C/H and ZnOx, and control the desorption of BTEX (mainly benzene, toluene, ethylbenzene, and p‐xylene) by weakening the binding of hydrogen proton to π electrons. Compared with the ordinary Zn/ZSM‐5 catalyst, the yield of BTEX is increased by nearly 10%, and the Zn/ZSM‐5‐Si catalyst exhibits excellent anti coking deactivation ability. This strategy together with mechanistic results may pave the rational design of efficient Zn/ZSM‐5 catalysts for aromatization reaction.