Energetics of phosphate frameworks containing zinc and cobalt: NaZnPO{sub 4}, NaH(ZnPO{sub 4}){sub 2}, NaZnPO{sub 4}.H{sub 2}O, NaZnPO{sub 4}.4/3 H{sub 2}O, and NaCo{sub x}Zn{sub 1-x}PO{sub 4}.4/3 H{sub 2}O
- Peter A. Rock Thermochemistry Laboratory, NEAT ORU, and Chemistry Department, University of California at Davis, Davis, CA 95616 (United States)
Differential scanning calorimetry and high temperature oxide melt solution calorimetry were used to study the enthalpy of the {alpha}-{beta} phase transformation of NaZnPO{sub 4} and enthalpies of formation of {alpha}-NaZnPO{sub 4}, NaH(ZnPO{sub 4}){sub 2}, NaZnPO{sub 4}.H{sub 2}O, and NaCo{sub x}Zn{sub 1-x}PO{sub 4}.4/3 H{sub 2}O (x=0, 0.1, 0.2, 0.3). The enthalpies of formation from the oxides of cobalt substituted in NaZnPO{sub 4}.4/3 H{sub 2}O do not depend on cobalt content, confirming similar acid-base interactions for Zn-PO{sub 4} and Co-PO{sub 4}. While water molecules stabilize zinc phosphate frameworks through solvating a cation or forming extra hydrogen bonds, the partial substitution of water for sodium oxide to form NaH(ZnPO{sub 4}){sub 2} represents the formation of an acidic compound with weaker acid-base interactions and less exothermic enthalpy of formation from oxides than Na{sub 2}(ZnPO{sub 4}){sub 2}. - Graphical abstract: Relative stability of NaZnPO{sub 4} dense phases, open frameworks, and hydrated frameworks. Enthalpy of interaction between water and NaZnPO{sub 4} frameworks is presented by reaction: NaZnPO{sub 4} (cr, open framework) + nH{sub 2}O (l) {yields} NaZnPO{sub 4}.nH{sub 2}O (cr, hydrated framework)
- OSTI ID:
- 21043826
- Journal Information:
- Journal of Solid State Chemistry, Vol. 180, Issue 9; Other Information: DOI: 10.1016/j.jssc.2007.06.017; PII: S0022-4596(07)00253-8; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
High microwave susceptibility of NaH{sub 2}PO{sub 4}{sm_bullet}2H{sub 2}O: Rapid synthesis of crystalline and glassy phosphates with NASICON-type chemistry
Temperature-dependent frameworkâtemplate interaction of |Na{sub 6}(H{sub 2}O){sub 8}|[ZnPO{sub 4}]{sub 6} sodalite