Acidity of crystalline zirconium phosphate

Metal phosphate catalyzed dehydration of sorbitol under hydrothermal conditions

“…It is reported that the surface area of zirconium phosphate increases with calcination temperature [52]. The gradually decrease in activity of both ZrP-1 and ZrP-2 by calcination at 400 • C could be explained by the gradually increase of the strong acidity during the thermal treatment up to 400 • C. The abruptly decrease in activity of ZrP-2 by calcination at 600 • C could be explained by the abruptly decrease of the total acidity when the temperature treatment is higher than 450 • C, as reported [53,54].…”

Lead recovery from PbZrO3 using wet ball-mill technique and hydrothermal synthesis of α-zirconium phosphate from wastewater for resource recovery

“…5(a) drew a similar curve for each other. The curves consisted of two plateaus, each plateau corresponding to the exchange of 1 mol of a hydrogen ion with a sodium ion per mol of phosphate, because the crystalline ␣-Zr(HPO 4 ) 2 ·H 2 O has two types of acid sites with a remarkably different acid strength from each another, in which the weak acid site is P-OH group with strong interaction with crystal water and the strong acid site is free P-OH [15]. Furthermore, the fully crystallized ␣-Zr(HPO 4 ) 2 ·H 2 O exhibits definite zero slope in titration curve since one solid-solution phase is formed.…”

“…have attracted much attention because of their excellent properties as cation exchangers [6][7][8][9][10][11][12], acid catalyst [13][14][15] and host material for intercalating polar molecules [16]. The crystalline ␣-Zr(HPO 4 ) 2 ·H 2 O was mainly prepared using a pure starting material through two different routs.…”

Structural Features of the Reactives Sites in α-M(DPO4)2·D2O(M= Ti, Zr, Pb): Hydrogen-Bond Network and Framework

“…acid solids (8), ion exchangers (9), sensors (10), and host materials for intercalation reactions (11,12). Acidic materials based on layered hydrogen phosphates…”