The similarities and differences in structural characteristics and physico-chemical properties of AgAlBEA and AgSiBEA zeolites

Influence of the postsynthesis preparation procedure on catalytic behaviour of Ag-loaded BEA zeolites in the hydrodechlorination of 1,2-dichloroethane into value added products

“…This phenomenon is probably related to decrease in the amount of strong Brønsted acidic sites due to partial ion exchange between proton of bridging hydroxyls Si-O(H)-Al groups with silver ions upon introduction of Ag into the HAlBEA zeolite. Similar observations were already reported in our previous work [42]. Such a zeolite modification resulted in a decrease of the cock formation upon hydrodechlorination process on red-C-Ag2.0HAlBEA and in the consequence a lower drop of 1,2-dichloroethane conversion.…”

“…As it is showed in Figure 1 and 2, in DR UV-vis spectra of as prepared Ag2.0HAlBEA and Ag2.0SiBEA two bands at 214 and 270-305 nm are present related to the charge transfer transition between 4d 10 and 4d 9 5s 1 level of highly dispersed Ag + species and charge transfer transitions in BEA framework, respectively, in line with earlier reports for Ag-MFI zeolites, Ag/Al2O3, Ag + /ZSM-5 and AgBEA [36,[39][40][41][42]. The absence of the bands at higher wavelength between 350 and 500 nm suggests that silver nanoclusters (Agn δ+ ) and metallic silver nanoparticles are not present in as prepared Ag2.0HAlBEA and Ag2.0SiBEA.…”

Ag–Ni bimetallic SiBEA zeolite as an efficient catalyst of hydrodechlorination of 1,2-dichloroethane towards ethylene

“…1) contains characteristic band at 214 nm, strongly related to the charge transfer transition between 4d 10 and 4d 9 5s 1 level of highly dispersed mononuclear Ag(I), in line with earlier reports for Ag-MFI, Ag + /ZSM-5 and AgBEA zeolites, or Ag/Al 2 O 3 , [18][19][20][21][22].…”

Identification of the silver state in the framework of Ag-containing zeolite by XRD, FTIR, photoluminescence,109Ag NMR, EPR, DR UV-vis, TEM and XPS investigations

“…Probably, this is related with the presence in the former ones of much bigger amount of isolated Ag n + clusters. Two bands at 208 and 272-300 nm observed for both as prepared Ag 3.0 SiBEA and Ag 6.0 SiBEA are probably related to charge transfer transition in BEA framework observed also for silver-free SiBEA, as we have reported earlier [49]. (111), (200), (220) and (311) lattice planes of the face-centered cubic metallic silver (JCPDS: 03-065-2871) (Fig.…”