Ag-Zeolite-based adsorbents were prepared in order to investigate the nature of the Ag species present in the structure and its correlation with their adsorption capacity and affinity towards ethylene. Na+ in NaA were partially replaced with Ag+ by varying the AgNO3 concentration used in the aqueous solutions, obtaining two dissimilar Ag+ exchange levels. The exchanged zeolites were treated at 90 °C for 12 h and at 350 °C for 4 h in N2 atmosphere. The X-ray diffraction (XRD), UV–visible (UV–Vis), and high-resolution transmission electron microscopy (HRTEM) analyses indicated that thermal treatment could induce framework distortion and reordering of the original Ag+ into different Ag species (Ag and Ag2O nanoparticles, nanoparticulate aggregates and Agmn+ clusters). In an overall analysis, the highest adsorption capacity and affinity towards ethylene were obtained for the samples containing mainly silver cations and reoxidizing-silver species that better promote 5 s1<->π–interaction. The increase of silver loading in heat-treated zeolite could not ensure higher olefin adsorption, due to the occurrence of non-oxidizable species. Nevertheless, at low pressure, these samples showed good affinity towards ethylene. Despite presenting inactive nanoparticles against olefin, the high content of accessible charged species remnants even after high-temperature treatment could be responsible for the improved ethylene adsorption.
Ethylene adsorption onto thermally treated AgA-Zeolite / Monzon, J. D.; Pereyra, A. M.; Gonzalez, M. R.; Legnoverde, M. S.; Moreno, M. S.; Gargiulo, N.; Peluso, A.; Aprea, P.; Caputo, D.; Basaldella, E. I.. - In: APPLIED SURFACE SCIENCE. - ISSN 0169-4332. - 542:(2021), p. 148748. [10.1016/j.apsusc.2020.148748]
Ethylene adsorption onto thermally treated AgA-Zeolite
Gargiulo N.;Peluso A.;Aprea P.;Caputo D.;
2021
Abstract
Ag-Zeolite-based adsorbents were prepared in order to investigate the nature of the Ag species present in the structure and its correlation with their adsorption capacity and affinity towards ethylene. Na+ in NaA were partially replaced with Ag+ by varying the AgNO3 concentration used in the aqueous solutions, obtaining two dissimilar Ag+ exchange levels. The exchanged zeolites were treated at 90 °C for 12 h and at 350 °C for 4 h in N2 atmosphere. The X-ray diffraction (XRD), UV–visible (UV–Vis), and high-resolution transmission electron microscopy (HRTEM) analyses indicated that thermal treatment could induce framework distortion and reordering of the original Ag+ into different Ag species (Ag and Ag2O nanoparticles, nanoparticulate aggregates and Agmn+ clusters). In an overall analysis, the highest adsorption capacity and affinity towards ethylene were obtained for the samples containing mainly silver cations and reoxidizing-silver species that better promote 5 s1<->π–interaction. The increase of silver loading in heat-treated zeolite could not ensure higher olefin adsorption, due to the occurrence of non-oxidizable species. Nevertheless, at low pressure, these samples showed good affinity towards ethylene. Despite presenting inactive nanoparticles against olefin, the high content of accessible charged species remnants even after high-temperature treatment could be responsible for the improved ethylene adsorption.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.