scholarly journals Phase equilibria in systems involving the rare-earth oxides. Part II. Solid state reactions in trivalent rare-earth oxide systems

1960 ◽  
Vol 64A (4) ◽  
pp. 317 ◽  
Author(s):  
S. J. Schneider ◽  
R. S. Roth
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Phase Equilibria ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Solid State Reactions ◽  
Oxide Systems ◽  
Trivalent Rare Earth ◽  
The Rare Earth

Nano Crystallite ZrO2, La2O3 and CeO2: Synthesis, Characterization and their Properties

2013 ◽  
Vol 209 ◽  
pp. 212-215
Author(s):  
A.K. Patel ◽  
A.R. Umatt ◽  
B.S. Chakrabarty
Keyword(s):  
Rare Earth ◽  
Surface Area ◽  
Gas Adsorption ◽  
Chemical Properties ◽  
Rare Earth Oxide ◽  
Combustion Method ◽  
Rare Earth Oxides ◽  
Precipitation Method ◽  
Reaction Conditions ◽  
The Rare Earth

It is well known that a minor addition of rare earth oxides can provide a beneficial effect towards various catalytic reactions. Use of rare earth oxide in different applications could improve commercial productivity in an affordable way. Among the rare earth oxides, ZrO2, La2O3 and CeO2 are very interesting due to their various characteristics showing a large range of applications in organic reactions. The changes in the molecular properties of materials at the nano scale level greatly enhance their physical properties as well as chemical properties and activity. Due to the extremely small size of the particles, an increased surface area is provided to the reactant enabling more molecules to react at the same time, thereby speeding up the process. In this work, the enhancement in the catalytic activity of these nano structured rare earth oxides has been studied under different reaction conditions. Nano crystalline ZrO2, La2O3 and CeO2 samples were synthesized using precipitation method and optimum reaction conditions have been established; whereas the corresponding bulk samples were synthesized by combustion method. The identification of phase and crystalline size of synthesized oxides have been done by X-ray diffraction, the band gape of these three oxides in both the forms has been analyzed by UV absorbance and surface area has been determined by gas adsorption analysis (BET). Moreover their different properties and the activity of nano crystallite oxides have also been compared with their bulk counterparts. Even the activity of ZrO2 is also compared with the rare earth oxides La2O3 and CeO2.

scholarly journals Dephosphorization of hot metal using rare earth oxide-containing slags

2020 ◽  
Vol 39 (1) ◽  
pp. 520-526
Author(s):  
Maolin Ye ◽  
Xiaojun Xi ◽  
Shufeng Yang ◽  
Jingshe Li ◽  
Feng Wang
Keyword(s):  
Rare Earth ◽  
Maximum Degree ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Oxide Content ◽  
Hot Metal ◽  
Factors Influencing ◽  
The Rare Earth

AbstractAn innovative rare earth oxide-containing slag for hot metal dephosphorization was proposed, and the factors influencing the efficiency during the dephosphorization of hot metal using rare earth oxide-containing slags were also studied. An increase in the temperature up to 1,550°C is beneficial to the dephosphorization process, and the maximum degree of dephosphorization for slags containing 6 wt% rare earth oxides is 44.49%; further temperature increases would deteriorate the efficiency, and the degree of dephosphorization decreases to 37.38% at 1,600°C. An increase in the basicity of slags up to 3.0, and the rare earth oxide content up to 6 wt%, improves the dephosphorization efficiency; further increase in the basicity and rare earth oxide content, the efficiency has almost no change. It was also found that an increase in the quantity of slags is beneficial to the dephosphorization reaction.

scholarly journals Catalytic Oxidation of HCHO over the Sodium-Treated Sepiolite-Supported Rare Earth (La, Eu, Dy, and Tm) Oxide Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 328 ◽  
Author(s):  
Ning Dong ◽  
Qing Ye ◽  
Mengyue Chen ◽  
Shuiyuan Cheng ◽  
Tianfang Kang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rare Earth ◽  
Catalytic Oxidation ◽  
Rare Earth Oxide ◽  
Catalytic Performance ◽  
Rare Earth Oxides ◽  
Hydroxyl Groups ◽  
In Situ Drifts ◽  
The Rare Earth

The sodium-treated sepiolite (NaSep)-supported rare earth oxide (RE/NaSep; RE = La, Eu, Dy, and Tm) samples were prepared using the rotary evaporation method. Physicochemical properties of these materials were characterized by XRD, SEM, BET, FTIR, XPS, H2–TPR, NH3–TPD, and in situ DRIFTS, and their catalytic activities for formaldehyde (HCHO) (2000 ppm) oxidation were evaluated. The results show that loading of the rare earth oxide on NaSep improved its catalytic performance. Among all the samples, Eu/NaSep performed the best, and complete HCHO conversion was achieved at a temperature of 150 °C and a gas hourly space velocity of 240,000 mL/(g h); a good catalytic activity was still maintained after 45 h of stability test. The catalytic oxidation mechanism of HCHO was studied using the in situ DRIFTS technique. As a result, the effective and stable catalytic performance of the Eu/NaSep sample was mainly due to the presence of hydroxyl groups on the sepiolite surface and the doped rare earth oxides, which contributed to its high performance. HCHO oxidation underwent via the steps of HCHO + O2 → HCOO− + OH− → H2O + CO2. It is concluded that the optimal catalytic activity of Eu/NaSep was associated with the highest Oads/Olatt atomic ratio, the largest amount of hydroxyl groups, the highest acidity, and the best reducibility. The present work may provide new insights into the application in the removal of high-concentration HCHO over the rare earth oxides supported on natural low-cost clays.

scholarly journals THE SOLID STATE CHEMISTRY OF RARE EARTH OXIDE SYSTEMS. Technical Progress Report, 1967--1968.

1968 ◽  
Author(s):  
L. Eyring ◽  
M.S. Jenkins ◽  
V. Scherer ◽  
G.D. Stone ◽  
R.P. Turcotte ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Technical Progress ◽  
Rare Earth Oxide ◽  
Progress Report ◽  
Solid State Chemistry ◽  
Oxide Systems

On the relation between lattice parameter and O/M ratio for uranium dioxide-trivalent rare earth oxide solid solution

1981 ◽  
Vol 102 (1-2) ◽  
pp. 40-46 ◽  
Author(s):  
Toshihiko Ohmichi ◽  
Susumu Fukushima ◽  
Atsushi Maeda ◽  
Hitoshi Watanabe
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Uranium Dioxide ◽  
Rare Earth Oxide ◽  
Lattice Parameter ◽  
Oxide Solid Solution ◽  
Trivalent Rare Earth
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