The use of deposited nanocarbon for characterization of zeolite supported metal catalyst

Zeolite supported metal catalysts are widely used while the electron beam sensitive zeolite makes the characterization of the catalysts using electron microscope (EM) very difficult. Herein a sacrificial-zeolite specimen preparation (SZSP) technique is developed for the EM analysis of the catalyst. The metal particles are transferred from the zeolite support to the deposited nanocarbon generated in the metal catalyzed hydrocarbon reaction. SAPO-34 zeolite with Al2O3 binder supported Pt catalyst is employed as the model catalyst. The propane dehydrogenation reaction is carried out to deposit the nanocarbon overlayer which the Pt particles are transferred to as the new support for EM observation. The original catalyst, the deposited nanocarbon, as well as the Pt particles on the new support are characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, thermogravimetry/differential thermal analysis, Raman spectrometry, and scanning transmission electron microscope. The nanocarbon deposited on SAPO-34 and Al2O3 are of different morphologies and structures. The as-observed distribution of Pt particles on the new support suggests the enrichment of Pt on SAPO-34. The shape and size of the Pt particles as well as the strong Pt–SAPO-34 interaction are directly observed.

Graphical abstractA sacrificial-zeolite specimen preparation technique using the in situ generated nanocarbon overlayer in metal catalyzed reaction as the new support for metal particles was developed for characterization of zeolite supported metal catalyst.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A sacrificial-zeolite specimen preparation technique. ► The characterization of zeolite supported catalyst using electron microscope. ► The metal particles were transferred to nanocarbon overlayer. ► The nanostructure of the Pt particles and strong Pt–SAPO-34 interactions.