Preparation of Heteropolyacid-intercalated Layered Double Hydroxide

We prepared W-based heteropolyacid (HPA) -layered double-hydroxide (LDH) composites. The effects of the intercalation process on the composite characteristics and the Keggin structure stability were then investigated. The HPA-LDH composites were prepared using ion-exchange method on Zn-Al (NO3) LDH and reconstruction method on Mg-Al (CO3) LDH. In both cases, d=1.47 nm spacing, indicating HPA intercalation to LDH, was identified. [SiW12O40] 4- was hydrolyzed into [SiW11O39] 8- during ion change processing, thereby obtaining [SiW11O39] 8- -LDH composites.