中国科学院大连化物所刘中民团队报道了实现在单催化剂床上生产高选择性轻质烯烃和对二甲苯的组合策略。相关研究成果发表在2024年3月13日出版的《美国化学会杂志》。

通过新型反应工艺和形状选择性催化策略实现多种高附加值化工生产，是实现高效低碳催化工艺的关键。

该工作开发了甲醇-甲苯共反应系统，并应用反应路径引导和形状选择催化的组合控制策略，在单一HZSM-5催化剂床上成功生产了轻质烯烃和对二甲苯。共进料甲苯还提供了反应性和流动性的芳烃库物种，这些物种改变了HZSM-5上甲醇反应复杂网络中的主要反应途径，并促进了乙烯的形成。

研究人员首次采用实验和理论技术直接捕获并鉴定了关键反应中间体亚甲基环二烯。这有助于提出乙烯主要生成的催化循环，更重要的是，丰富了甲醇制烃（MTH）化学和烃库机制。此外，0.4HZSM-5@S-1-CLD通过silicalite-1外延生长和硅烷化方法改性的优化HZSM-5催化剂，实现了轻质烯烃（尤其是乙烯）和对二甲苯的高选择性生产，同时保持了优异的反应活性。

这种高效的共反应路线在合成聚烯烃和聚酯工业的原材料方面，具有重要的先导意义。联合控制策略的建立为复杂催化过程中，多种目标化学品的联合生产提供了一个模型。

附：英文原文

Title: Combined Strategies Enable Highly Selective Light Olefins and para-Xylene Production on Single Catalyst Bed

Author: Yimo Wu, Jingfeng Han, Wenna Zhang, Zhengxi Yu, Kunyuan Wang, Xudong Fang, Yingxu Wei, Zhongmin Liu

Issue&Volume: March 13, 2024

Abstract: Achieving multiple high-value-added chemical production through novel reaction processes and shape-selective catalytic strategy is the key to realizing efficient low-carbon catalytic processes. In this work, a methanol–toluene coreaction system was developed, and combined control strategies of reaction pathway guidance and shape-selective catalysis were applied for the successful production of light olefins and para-xylene on single HZSM-5 catalyst bed. Cofeeding toluene additionally provides reactive and flowing aromatic hydrocarbon pool species that change the dominant reaction pathway in the complex network of the methanol reaction on HZSM-5 and promote the formation of ethylene. For the first time, the key reaction intermediates methylmethylenecyclodiene are directly captured and identified by experimental and theoretical techniques. This helps to propose the catalytic cycle for the dominant generation of ethylene and, more importantly, enriches the methanol-to-hydrocarbons (MTH) chemistry and hydrocarbon pool mechanism. Furthermore, 0.4HZSM-5@S-1-CLD, an optimized HZSM-5 catalyst modified by the silicalite-1 epitaxial growth followed by silanization approach, realizes highly selective production of light olefins (especially ethylene) and para-xylene, while excellent reactant activity is maintained. This highly efficient coreaction route gives an important leading significance in synthesizing the raw materials for the polyolefin and polyester industries. The establishment of the combined control strategies provides a model for the joint production of multiple target chemicals in complex catalytic processes.

DOI: 10.1021/jacs.3c12087

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.3c12087