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 ℃ 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 th

e 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.