Characterization and thermal behavior of amorphous cerium phosphate
摘要:
The thermal behavior of amorphous cerium phosphate has been characterized by X-ray powder diffraction, thermal gravimetric and differential thermal analysis, Fourier transform infrared and Raman spectroscopy. Crystallization from amorphous phase occurred at around 773 K to form crystalline cerium pyrophosphate, CeP2O7. Further heating induced a phase transition from CeP2O7 to CePO4 at 923 K via coexistence of a small amount of metaphosphate phase.
the preparation of CeP·2H2O was the mixing ratio of 1.5—2.0, heating temperature 175—200 °C, heating time 5 h, and water vapor pressure 5.0—7.0 atm. The results of X-ray powder diffraction, fluorescent X-ray analysis, differential thermal analysis and thermogravimetry (DTA-TG), IR spectrum, and phase transition showed that CeP·2H2O is a novel crystalline layered cerium(IV) phosphate having a interlayer
Role of cerium pyrophosphate for improving protonic conduction and stabilization of SDP.2H2O composite electrolytes
作者:Pawan Kumar、Dharm Veer、Deshraj Singh、Aravind Kumar、Ram S Katiyar
DOI:10.1016/j.inoche.2023.111614
日期:2023.12
Proton-conducting (1-x)NaHPO·2HO/xCePO (x = 0.1–0.4) composites were prepared and the conduction behaviour was investigated at intermediatetemperatures. The presence of water in CePO increased the number of jump sites and facilitated the hopping of protons, thereby increasing the protonconductivity of the compositeelectrolytes. In this work, we systematically addressed some aspects and presented
Cerium-titanium pyrophosphates Ce1-xTixP2O7 (with x=0,0.50, and 1.0), which are novel phosphate materials developed as UV-shielding agents for use in cosmetics, were characterized by X-ray diffraction, X-ray fluorescent analysis, UV-vis reflectance, and Raman spectroscopy. Since the optical reflectance shifted to lower wavelengths by the crystallization of the phosphates and the stabilization of the amorphous state of the cerium-titanium pyrophosphates was carried out by doping niobium (Nb). Raman spectroscopic study of the phosphate showed that P-O-P bending and stretching modes decreased with the loading of Nb, accompanying with the formation of Nb-O stretching mode. Therefore, the increase in the amount of the non-bridging oxygen in the amorphous phosphate should be the reason for the inhibition of the crystallization. This stabilization is a significant improvement, which enables to apply these amorphous phosphates not only to cosmetics and paints, but also plastics and films. (c) 2005 Elsevier 13N. All rights reserved.
Proton conductors of cerium pyrophosphate for intermediate temperature fuel cell
作者:Minh-Vien Le、Dah-Shyang Tsai、Chia-Ying Yang、Wen-Hung Chung、Hsin-Yi Lee
DOI:10.1016/j.electacta.2011.05.040
日期:2011.7
The crystal structure and proton conductivity of cerium pyrophosphate are investigated to explore its potential electrolyte applications for intermediate temperature fuel cell. Among the CeP(2)O(7) thin plates, which are sintered at 300-900 degrees C, the 450 degrees C CeP(2)O(7) sample exhibits superior proton conductivity under humidified conditions. Its conductivity, measured with impedance spectroscopy, is higher than 10(-2)S cm(-1) in the intermediate temperature range, with a maximum value 3.0 x 10(-2)S cm(-1) at 180 degrees C. When 10 mol% Mg is doped on the Ce site of CeP(2)O(7), the maximum conductivity is raised to 4.0 x 10(-2)S cm(-1) at 200 degrees C. The Mg doping not only raises the conductivity, but also shifts and widens its temperature window for electrolyte applications. Ce(0.9)Mg(0.1) P(2)O(7) is considered a more appropriate composition, with conductivity > 10(-2)S cm(-1) between 160 and 280 degrees C. Accordingly, a hydrogen-air cell is built with the Ce(0.9)Mg(0.1) P(2)O(7) electrolyte and its performance is measured. The fuel cell generates electricity up to 122 mA cm(-2) at 0.33 V using 50% H(2) at 240 degrees C. (C) 2011 Elsevier Ltd. All rights reserved.