Catalytic conversion of light alkanes to aromatics by metal-containing HZSM-5 zeolite catalysts—A review

• DOI: 10.1016/j.fuproc.2021.106770
• Publication Date: 2021-03-06T00:00:34Z
• Authors: Dongyang Liu; Liyuan Cao; Guohao Zhang; Liang Zhao; Jinsen Gao; Chunming Xu
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract The directly catalytic conversion of C2-C6 alkanes to aromatics has aroused widespread interest from both academia and industry because of the growing demand for aromatics. Compared with pure HZSM-5 zeolites, the addition of metal species is required to enhance the selectivity of BTX by inhibiting undesirable side reactions. This paper reviewed the research progress of aromatization for light alkanes on HZSM-5 zeolites and its metal-containing catalysts based on theoretical and experimental research. The chemical states of metal species and dehydrogenation mechanisms of Zn and Ga-containing HZSM-5 catalysts are introduced in detail. The interaction of Zn or Ga with HZSM-5 zeolite produces Zn or Ga-Lewis acid sites that can promote the dehydrogenation of alkanes and intermediate products, thereby increasing the selectivity of BTX. On Zn-containing HZSM-5, only the Zn species were found to be involved in the dehydrogenation activation process of alkanes. In contrast, on Ga-containing HZSM-5, the acid-base pairs composed of Ga species with adjacent basic oxygen ions are responsible for the dehydrogenation of alkanes. However, there is still controversy over the active species of alkanes dehydrogenation, which needs further investigation.