Effects of ion-exchange on the pervaporation performance and microstructure of NaY zeolite membrane

Pervaporation performance of NaY zeolite membranes is improved by ion-exchange with di-valent nitrate salt . Different nitrate salts, including Co(NO 3 ) 2 , Mg(NO 3 ) 2 , Zn(NO 3 ) 2 , Ca(NO 3 ) 2 , Cu(NO 3 ) 2 , KNO 3 , and AgNO 3 , have great effects on the channel structure and water affinity of the NaY zeolite membrane. When the concentration of nitrate salt, ion-exchange temperature and time are 0.1 mol·L −1 , 50 °C and 2 h, the ion-exchange degree order of NaY zeolites is Ag +  > K +  > Ca 2+ > Zn 2+  ≫ Co 2+  > Mg 2+ . Especially, Ag + and K + cation exchange degree of NaY zeolites are achieved to 96.54% and 82.77% in this work. BET surface, total pore capacity, pore size distribution and water contact angle of the ion-exchanged NaY zeolites are all disordered by mono- and di-valent cations. Di-valent nitrate salt is favor for increasing the dehydration performance of NaY zeolite membranes by ion-exchange. When the ion-exchange solution is Zn(NO 3 ) 2 , the total flux variation and separation factor variation of the NaY membrane (M-5) are −45% and 230% for separation of 10% (mass) H 2 O/EtOH mixture by pervaporation, and the ion-exchanged membranes showed good reproducibility.