18649-05-3Relevant articles and documents
Direct electrochemical synthesis of oxygenates from ethane using phosphate-based electrolysis cells
Fujiwara, Naoya,Honda, Yusuke,Kikuchi, Ryuji,Kobayashi, Yasukazu,Oyama, Shigeo Ted,Tada, Shohei
, p. 11199 - 11202 (2020)
Ethane was converted directly to acetaldehyde and ethanol by partial oxidation at 220 °C and ambient pressure using an electrolysis cell with a proton-conducting electrolyte, CsH2PO4/SiP2O7, and Pt/C electrodes. The ethane conversion and the selectivity to the products increased with the voltage applied to the cell. It was found that O species generated by water electrolysis functioned as a favorable oxidant for partial oxidation of ethane on the Pt/C anode at intermediate temperatures. The production rates of acetaldehyde and ethanol recorded in this study were significantly higher than those in preceding reports.
An oxide ion and proton co-ion conducting Sn0.9In 0.1P2 O7 electrolyte for intermediate- temperature fuel cells
Chen, Xilin,Wang, Chunsheng,Payzant, E. Andrew,Xia, Changrong,Chu, Deryn
, p. B1264-B1269 (2008)
The ionic conductivity of Sn0.9In0.1P2 O7 ceramic was investigated under various atmospheres within the temperature range of 130-230°C. Similar to mixed-conductive perovskite oxides at high temperatures (such as SrCe0.95Yb0.05 O 3-α, La0.9 Sr0.1Ga0.8 Mg 0.2 O3-α at 600-1000°C), Sn0.9In 0.1P2 O7 can conduct both protons and oxide ions at low temperatures (130-230°C). The conductivity of Sn 0.9In0.1P2 O7 reaches 0.019 Scm at 200°C in wet nitrogen. Its transport numbers determined by steam concentration cells are around 0.76 for a proton and 0.12 for an oxide ion. The performance of direct methanol fuel cells at 170°C using mixed-ion conductive Sn0.9In0.1P2 O7 electrolyte is higher than that at 235°C using pure proton conductive CsH2PO4 electrolyte. This is attributed to direct oxidation of CO at the anode by the oxide ions generated at the cathode and moved through the Sn0.9In0.1P2 O7 electrolyte.
Thermal analysis of CsH2PO4 nanoparticles using surfactants CTAB and F-68
Hosseini,Mohamad,KaHum,Wan Daud
, p. 197 - 202 (2010)
A study concerned to thermogravimetric analysis is performed in cesium dihydrogen phosphate (CsH2PO4) that was synthesized, using cetyltrimethylammonium-bromide (CTAB), polyoxyethylene-polyoxypropylene (F-68) and mixture of (F-68:CTAB) with two mole ratio 0.06 and 0.12 as surfactant. The dehydration behavior of particles was studied using thermal gravimetric analysis and differential scanning calorimetric. Subsequently, the experimental results indicated that the first dehydration temperature in the range of 237-239 °Cupon heating, the second peaks occur at temperature range 290-295 °C and overlapping in the thermogravimetric events is observed. The mass loss values are obtained in the range of 6.62-6.97 wt% that is less than reported theoretical value 7.8 wt%. These values show well compatibility of reaction CsH2PO4 to Cs2H2P2O 7 with 3.92 wt% whereas mass loss value of CsH2PO 4 to CsPO3 is less than theoretical value 7.8 wt%. The activation energy of two steps dehydration are calculated using Kissinger equation for the samples synthesized via CTAB and (F-68) with minimum value mass loss 6.62% and maximum value mass loss 6.97%, respectively. The calculation results reveal that the reaction rate in the first step (CsH2PO 4 → Cs2H2P2O7) is faster than the second step (CsH 2PO4 → CsPO3). The weight loss values of the samples demonstrate that existence of CTAB can be considered as effective factor which prevents more weight loss during the dehydration process. Akademiai Kiado, Budapest, Hungary 2009.
Electrical and thermodynamic properties of Cs0.97 Rb 0.03H2PO4
Lavrova,Martsinkevich,Ponomareva
, p. 795 - 801 (2009)
The transport properties of Cs0.97Rb0.03H 2PO4 have been studied using polycrystalline samples and single crystals. The mixed salt is isostructural with cesium dihydrogen phosphate and has slightly smaller unitc
CRITICAL SLOWING-DOWN AND STATIC DIELECTRIC CONSTANT OF MONOCLINIC RbD2PO4.
Komukae,Makita
, p. 4359 - 4369 (1985)
The real and imaginary parts of the complex dielectric constant along the b axis of monoclinic RbD//2PO//4 were measured in a frequency range between 10**6 Hz and 10**9 Hz. It was found that RbD//2PO//4 shows dielectric critical slowing-down near the ferrielectric phase transition point. In addition, the static dielectric constants ( epsilon //0) of RbD//2PO//4 and the partially deuterated crystal Rb(D//0//. //3H//0//. //7)//2PO//4 were also measured at 10**4 Hz. A theoretical expression of epsilon //0 for a ferrielectric phase transition was obtained on the basis of the quasi-one-dimensional Ising model with assumed two sublattices. The remarkable deviations of epsilon //0 from the Curie-Weiss law observed in these crystals were analyzed successfully by the present theoretical result and the experimental results were discussed.
Intermediate-temperature fuel cell employing CsH2PO 4/SiP2O7-based composite electrolytes
Matsui, Toshiaki,Kukino, Tomokazu,Kikuchi, Ryuji,Eguchi, Koichi
, p. A339-A342 (2006)
The proton-conductive electrolytes based on CsH2 PO4 SiP2 O7 composites with various molar ratios were synthesized, and their structural and electrochemical properties were investigated at intermediate temperatures. The interfacial chemical reaction betwe
Electrical conductivity and thermal stability of (1-x)CsH 2PO4/xSiPyOz (x = 0.2-0.7) composites
Ponomareva,Shutova,Lavrova
, p. 1009 - 1014 (2008)
The physicochemical properties of (1 - x)CsH2PO4/xSiP y O z (x = 0.2-0.7) composites containing fine-particle silicon phosphates as heterogeneous additives have been studied at different humidities. The introduc
Surfactant effect on the conductivity behavior of CsH2PO 4: Characterization by electrochemical impedance spectroscopy
Hosseini,Homaiee,Mohamad,Malekbala,Khadum
, p. 1689 - 1694 (2011)
Cesium dihydrogen phosphate (CDP) nanoparticles were synthesized using the surfactants cetyltrimethyl ammonium bromide (CTAB), polyoxyethylenepolyoxypropylene (F-68) and (F-68:CTAB) with molar ratio 0.06. The samples conductivity such as CDPCTAB, CDPF-68 and CDP(F-68:CTAB)0.06 was studied by impedance spectroscopy in the frequency range 0.01 Hz to 1 MHz. The Nyquist plots were drawn at different temperatures of 210, 230 and 260 °C, which are defined below transition, phase transition and above transition, respectively. The measured conductivities obey the Arrhenius relation. The influence of surfactants on conductivity are more significant at higher temperature due to grain boundary. The conductivity of CDPCTAB increased slightly with increasing temperature to 260 °C, whereas the conductivity of other samples decreased with increasing temperature over 230 °C. The results indicated that the conductivities increase in the order of CDPCTAB>CDP (F-68:CTAB)0.06>CDPF-68. These are in accordance to the ion exchange capacities of the samples that the surfactant shows a direct influence on the samples proton mobility. It is found that the conductivity of CsH2PO4 is influenced by surfactant type.
A study of thermal behavior of cesium phosphate
Zhang, Guoliang,Peng, Zhijian,Li, Chunshan
, p. 1063 - 1070 (2016/07/06)
Cesium phosphates with different Cs/P molar ratios were prepared by a solution evaporation method. X-ray powder diffraction, thermogravimetric, and differential thermal analyses were performed in order to reveal the chemical transformation and phase compositions which take place during the heating of the mixtures Cs2CO3/(NH4)2HPO4 and CsNO3/(NH4)2HPO4 as well as individual compound. The effects of the Cs/P molar ratio, Cs source and treatment temperature on thermal behavior of the cesium phosphates were investigated. The results showed that different reactions take place with molar ratio from 1/2 to 3/1. Meanwhile, the thermostability of Cs2CO3 and CsNO3 intimately affects the phase composition and phase transition during heating process. However, for all the Cs–P oxides samples, the crystallinity was decreased differently after higher temperature treatment.
