Liu Xiaoliang, Wang Chuanming, Zhou Jian, Liu Chang, Liu Zhicheng, Shi Jing, Wang Yangdong, Teng Jiawei, Xie Zaiku
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai Research Institute of Petrochemical Technology, SINOPEC Corp., Shanghai 201208, China.
China Petroleum and Chemical Corporation (SINOPEC Corp.), Beijing 100728, China.
Chem Soc Rev. 2022 Oct 3;51(19):8174-8200. doi: 10.1039/d2cs00079b.
Increasing social sustainability triggers the persistent progress of industrial catalysis in energy transformation and chemical production. Zeolites have been demonstrated to be pivotal catalysts in chemical industries due to their moderate acidity and versatile well-defined pore structures. However, in the context of enhancing the performances of zeolite catalysts, the perspectives on the diffusion regulations within the pores and channels in the bulk phases or external surfaces of the zeolites are often overlooked. Establishing the structure-transport-reactivity relationships in heterogeneous catalysis can provide rational guidelines to design high-performance catalysts. Herein, this tutorial review attempts to systematically depict an integrated picture of molecular transport behaviors in zeolite catalysts from macroscopic to microscopic perspectives. The advances in the accurate diffusion measurements employing both macroscopic and microscopic techniques are briefly introduced. The diffusion characteristics in zeolite catalysts under working conditions (, high temperature, multi-components, and reaction coupling) are then addressed. The macroscopic internal diffusion and the microscopic diffusion occurring in the micro-zones of zeolite crystals (, surface diffusion, diffusion anisotropy, and confined diffusion) are reviewed and discussed in more detail. These diffusion behaviors highly impact the underlying reaction mechanism, catalytic performances, and catalyst optimization strategies. Finally, the multi-type pore systems of practical zeolite catalysts in industrial reactors and their transport behaviors are analyzed. The fully-crystalline monolithic zeolites in the absence of binders are highlighted as rising-star catalytic materials for industrial applications. The research challenges in this field and the potential future development directions are summarized.
社会可持续性的增强推动了工业催化在能源转化和化学品生产方面的持续进步。由于其适度的酸性和多样且明确的孔结构，沸石已被证明是化学工业中的关键催化剂。然而，在提高沸石催化剂性能的背景下，人们往往忽视了对沸石体相或外表面孔道内扩散规律的研究。建立多相催化中的结构 - 传输 - 反应性关系可为设计高性能催化剂提供合理指导。在此，本教程综述试图从宏观到微观的角度系统地描绘沸石催化剂中分子传输行为的整体图景。简要介绍了采用宏观和微观技术进行精确扩散测量的进展。接着讨论了沸石催化剂在工作条件下（如高温、多组分和反应耦合）的扩散特性。更详细地综述和讨论了沸石晶体微区中发生的宏观内部扩散和微观扩散（如表面扩散、扩散各向异性和受限扩散）。这些扩散行为对潜在的反应机理、催化性能和催化剂优化策略有很大影响。最后，分析了工业反应器中实际沸石催化剂的多类型孔系统及其传输行为。无粘结剂的全结晶整体沸石作为工业应用中新兴的催化材料受到关注。总结了该领域的研究挑战和潜在的未来发展方向。
