纳米多孔颗粒床层中的长程扩散：陷阱与潜力

Long-range diffusion in beds of nanoporous particles: pitfalls and potentials.

作者信息

Vasenkov Sergey, Kärger Jörg

机构信息

Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnéstr. 5, 04103 Leipzig, Germany.

出版信息

Magn Reson Imaging. 2005 Feb;23(2):139-45. doi: 10.1016/j.mri.2004.11.057.

DOI:10.1016/j.mri.2004.11.057

PMID:15833604

Abstract

Owing to the recent progress in the area of hardware and software of the pulsed field gradient NMR technique, molecular transport in real-life zeolite systems, such as zeolite beds and particles of formulated fluid catalytic cracking (FCC) catalysts, can be investigated in detail. These studies have revealed a number of important features of molecular transport in zeolites, which are reviewed in the present paper. In particular, the anomalous character of intracrystalline diffusion in MFI-type zeolites, dependence of the tortuosity factor in zeolite beds on diffusion regime and the role of various modes of diffusion in transport limitations arising for catalytic reactions in FCC catalysts will be discussed.

摘要

由于脉冲场梯度核磁共振技术在硬件和软件领域的最新进展，可以详细研究实际沸石体系中的分子传输，如沸石床层和流化催化裂化（FCC）催化剂配方颗粒中的分子传输。这些研究揭示了沸石中分子传输的许多重要特征，本文将对这些特征进行综述。特别地，将讨论MFI型沸石晶内扩散的反常特性、沸石床层中曲折因子对扩散方式的依赖性以及FCC催化剂催化反应中各种扩散模式在传输限制中的作用。