Synthesis of microscale and nanoscale ZSM-5 zeolites: effect of particle size and acidity of Zn modified ZSM-5 zeolites on aromatization performance

Abstract

Zn/NZ5 zeolite exhibits a higher BTX yield because of the higher mesoporosity and strong Lewis acid sites formed by [ZnOZn]2+ species.

Enhanced Catalytic Performance of Zn‐containing HZSM‐5 upon Selective Desilication in Ethane Dehydroaromatization Process

“…This is consistent with the measured concentration of strong acid sites by ammonia TPD. The intensity of OH vibration at 3606 cm −1 , assigned to the Brønsted acid sites, decreases as the amount of zinc loading in C‐ and D‐ZSM‐5 increases, which is also in good agreement with the ammonia TPD results and previous studies . However, also some intensity decrease is observed for the bands at 3438, 3693, 3723 and 3740 cm −1 .…”

“…Generally, dehydroaromatization provides strongly reducing environment. Consequently, unreactive ZnO may be reduced to metallic zinc and leave the catalyst or some of reactive zinc species could anchor to the acid sites . Therefore, it is believed that the observed catalytic performance for all of the catalysts is the result of zinc, retained on active sites, strongly bound to the zeolite.…”

“…With the low price of natural gas – and even declining over time ‐, natural gas opens up an opportunity to produce BTX from the light hydrocarbon components of natural gas. Considering that ethane is often an abundant component in natural gas, the process for the direct conversion of ethane to BTX has gained increased attention in the industry for the last few decades . Hence, this work is focused on studying the direct conversion of ethane into BTX.…”

“…Considering that ethane is often an abundant component in natural gas, the process for the direct conversion of ethane to BTX has gained increased attention in the industry for the last few decades. [5][6][7][8] Hence, this work is focused on studying the direct conversion of ethane into BTX. ZSM-5 is a well-known zeolite with solid acid sites that has been developed for and is widely used in chemical and petroleum industrial processes such as isomerization, alkylation and hydrocracking.…”

“…[15][16][17][18][19][20][21][22][23] Numerous studies demonstrated that incorporation of Lewis acid metals such as Zn into zeolites modifies the surface acidity and enhances selectivity to BTX in light alkane dehydroaromatization. [7,15,18,[24][25][26][27] However, only a few studies have been dedicated to the performance and catalytic life-time enhancement of Zn-containing zeolite catalyst for ethane direct conversion to aromatics. Vosmerikova et al [28] studied the influence of zeolite framework structure for ethane dehydroaromatization on ZSM-5, ZSM-8, ZSM-11, and ZSM12 at 650°C.…”