Coke Formation over Zeolite Catalysts in Light Alkanes Aromatization and Anti-Carbon-Deposition Strategies and Perspectives: A Review
Yuewen Sun, Lihong Wei, Zhuang Zhang, Hongxiang Zhang, Yanlong Li
Abstract
The price of light aromatics, which are important chemical intermediates, is greatly affected by fluctuations in the oil market, and there is a gap in the supply. It is urgent to expand the source of aromatics to match the market demand. Being highly accessible, oxygen-free aromatization of light alkanes (C 1 –C 4 ), with high product selectivity and high cost-effectiveness, has attracted widespread interest from both academia and industry. However, the rapid deactivation of catalysts due to carbon deposition has seriously hindered the industrialization process. This Review presents the bifaciality of coke on catalysts and proposes a coke formation mechanism related to the dynamic migration of intermediates according to the type of catalyst active site. An emphasis is placed on creating a reaction microenvironment that resists carbon deposition by improving the mass-transfer efficiency, controlling the interaction between intermediates and active sites, adjusting silanol defects, and looking forward to future directions for development.