caa a22 4500 46911276X CHVBK 20180323133115.0 cr unu---uuuuu 170328e19920301xx s 000 0 eng 10.1007/BF02165278 doi (NATIONALLICENCE)springer-10.1007/BF02165278 Effect of γ-irradiation on the crystallinity and catalytic activity of NdX and NdY zeolites [Elektronische Daten] [M. Selim, A. Kira, S. Ali, S. Abdel-Hamid] Different Nd-zeolites were prepared from the original NaX and NaY zeolites by ion exchange. The hydrated and thermally activated (at 550 °C) samples obtained were irradiated with γ-rays of 1.5 and 10.0 Mrad. The unirradiated and irradiated samples were characterized mainly by X-ray diffraction and tested for catalytic activity in cumene cracking. The X-ray diffraction patterns indicated a slight decrease of crystallinity after irradiation. However, the irradiated samples exhibited higher catalytic activities than unirradiated ones. γ-Irradiated hydrated zeolites were found to possess comparable activities, whereas the irradiated dehydrated samples were more active. Higher irradiation doses resulted in more active dehydrated zeolites than those irradiated with a lower dose. The observed higher activity was attributed to the formation of tricoordinate aluminium atoms in the zeolite structure, leading to increase of the number of acidic sites and consequently to a catalytic activity. Akadémiai Kiadó, 1992 Selim M. National Research Center, Dokki, Cairo, Egypt aut Kira A. Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt aut Ali S. Faculty of Girls, Ain Shams University, Cairo, Egypt aut Abdel-Hamid S. Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt aut Journal of Radioanalytical and Nuclear Chemistry Kluwer Academic Publishers 164/4(1992-03-01), 229-240 0236-5731 164:4<229 1992 164 10967 https://doi.org/10.1007/BF02165278 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02165278 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Selim M. National Research Center, Dokki, Cairo, Egypt aut NATIONALLICENCE 700 1- Kira A. Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt aut NATIONALLICENCE 700 1- Ali S. Faculty of Girls, Ain Shams University, Cairo, Egypt aut NATIONALLICENCE 700 1- Abdel-Hamid S. Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt aut NATIONALLICENCE 773 0- Journal of Radioanalytical and Nuclear Chemistry Kluwer Academic Publishers 164/4(1992-03-01), 229-240 0236-5731 164:4<229 1992 164 10967 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer