Evolution and stabilization of subnanometric metal species in confined space by in situ TEM
نویسندگان
چکیده
Understanding the behavior and dynamic structural transformation of subnanometric metal species under reaction conditions will be helpful for understanding catalytic phenomena and for developing more efficient and stable catalysts based on single atoms and clusters. In this work, the evolution and stabilization of subnanometric Pt species confined in MCM-22 zeolite has been studied by in situ transmission electron microscopy (TEM). By correlating the results from in situ TEM studies and the results obtained in a continuous fix-bed reactor, it has been possible to delimitate the factors that control the dynamic agglomeration and redispersion behavior of metal species under reaction conditions. The dynamic reversible transformation between atomically dispersed Pt species and clusters/nanoparticles during CO oxidation at different temperatures has been elucidated. It has also been confirmed that subnanometric Pt clusters can be stabilized in MCM-22 crystallites during NO reduction with CO and H2.
منابع مشابه
In situ activation of a Ni catalyst with Mo ion for hydrogen evolution reaction in alkaline solution
In this study Ni catalyst have been activated during hydrogen evolution reaction (HER) by adding Mo ions into the alkaline electrolyte. After dissolving different amounts of ammonium molybdate in the 1M NaOH as electrolyte, Ni catalyst was used as cathode for HER. Afterwards a comparison between hydrogen overpotential measured in Ni catalyst with and without in situ activation has been made; th...
متن کاملEx-situ studies on calcinations of structural, optical and morphological properties of post-growth nanoparticles CeO2 by HRTEM and SAED
Nanocrystalline particles of Cerium Oxide (CeO2) have been prepared by the chemical precipitation method using Cerium nitrate and Urea with a molar ratio of 1:2. The results revealed that the formation of CeO2 fine particles is influenced by molar ratio of metal nitrates to fuel. Well faceted CeO2 nanoparticles, were synthesized by thermal-assisted dissociation ...
متن کاملEx-situ studies on calcinations of structural, optical and morphological properties of post-growth nanoparticles CeO2 by HRTEM and SAED
Nanocrystalline particles of Cerium Oxide (CeO2) have been prepared by the chemical precipitation method using Cerium nitrate and Urea with a molar ratio of 1:2. The results revealed that the formation of CeO2 fine particles is influenced by molar ratio of metal nitrates to fuel. Well faceted CeO2 nanoparticles, were synthesized by thermal-assisted dissociation ...
متن کاملIn Situ Analysis of Gut Residue of Corophium Volutator (Pallas) by Electron Probe Microanalysis after Exposure to Barytes Spiked Sediments
Corophium volutator (Pallas) has been recommended by the paris Commission as one of the standard species for testing chemical used in offshore oil and gas exploration/production. In the present study, gut contents of Corophium volutator have been analysed by electron probe microanalysis (EPMA) for BaSO4 and other heavy metal impurities after exposure tto spiked sediments followin...
متن کاملStructural, magnetic and dielectric properties of pure and Dy-doped Co3O4 nanostructures for the electrochemical evolution of oxygen in alkaline media
In this study, spinel-type cobalt oxide (Co3O4) and Co3-xDyxO4 (x = 0.04 and 0.05 molar ratio) nanoparticles were synthesized via combustion method at 700 °C. Crystallite nature, phase purity and thermal analysis of the prepared compounds were investigated by PXRD, FT-IR and TGA techniques. Structural analyses were performed by the FullProf program employing profile matching with constant scale...
متن کامل