Advanced scanning electron microscopy techniques for structural characterization of zeolites. Issue 16 (7th July 2022)

• Record Type: Journal Article
• Authors: Asano, Natsuko; Asahina, Shunsuke; Lu, Jinfeng; Xu, Jiani; Shen, Yanfeng; Qin, Zhengxing; Mintova, Svetlana
• Is Part Of: Inorganic chemistry frontiers. Volume 9:Issue 16(2022)
• Page Start: 4225
• Page End: 4231
• Publication Date: 2022-07-07
• Subjects: Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d2qi00952h
• Languages: English
• ISSNs: 2052-1553

Abstract

Abstract : Chemical etching after Ar ion beam cross sectioning enables the formation of zeolite internal nano structures to be observed directly using a newly developed highly sensitive scanning electron microscope. Abstract : In this work, low-voltage field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS) analyses were applied for the investigation of zeolite structures. Low-voltage electron imaging was applied to visualize the surface structures of ZSM-5 zeolites with a mosaic surface morphology, and cross-sectional imaging techniques were used to show the sub-surface etching of SAPO-34 zeolites that cannot otherwise be directly revealed by SEM. In the case of SAPO-34 zeo-type crystals, the hidden macropores with a framed butterfly shape introduced by NH4 F etching were revealed. In addition, the combined low-voltage imaging and EDS triple-detector analysis allowed recording of the near-surface-layer element distribution in the zeolite crystals; this was exemplified on SAPO-34 crystals during dissolution for the first time. The results showed that some inner parts of the SAPO-34 crystals are more vulnerable than the outermost shell of the crystals, which were preferentially removed during the NH4 F etching.