721880-19-9

Basic information

• Product Name: monacite
• Synonyms: monacite
• CAS NO: 721880-19-9
• Molecular Weight: 235.091
• Mol File: 721880-19-9.mol
• Article Data: 23

Chemical Properties

• CAS DataBase Reference: monacite(CAS DataBase Reference)
• NIST Chemistry Reference: monacite(721880-19-9)
• EPA Substance Registry System: monacite(721880-19-9)

Safety Data

• Hazardous Substances Data: 721880-19-9(Hazardous Substances Data)

Upstream product

• 6303-21-5 hypophosphorous acid 
• 86119-84-8 phosphoric acid 
• 7722-76-1 ammonium dihydrogen phosphate 
• 10124-31-9 ammonium dihydrogen phosphate 
• 19423-76-8 cerium(III) chloride heptahydrate 
• 18923-26-7 cerium(III) ion 

Downstream Products

• 86119-84-8 phosphoric acid 

Relevant articles and documents

Hydrothermal growth and morphology evolution of CePO4 aggregates by a complexing method

A facile hydrothermal route assisted by Na2H2EDTA (ethylenediaminetetraacetic acid disodium) has been successfully developed to prepare uniform cerium phosphate (CePO4) aggregates with different morphologies, such as peanut-like and spindle-like. It was found that the as-prepared uniform CePO4 aggregates were constructed with many nearly parallel aligned nanorods. The molar ratio of EDTA/Ce3+, solution pH and reaction time had great influences on the morphologies and sizes of the CePO4 samples. In our process of synthesis, Na2H2EDTA played important roles as complexing reagent and inducing agent on the formation of CePO4 aggregates. The possible growth mechanism for CePO4 aggregates was presented. Ce0.9Tb0.1PO4 aggregates with different morphologies were also prepared and their photoluminescence properties were characterized.

The synthesis and thermal stability of CaKCe(PO4)2 phosphate. Phase equilibria in the CaKPO4-CePO4 system

The compound CaKCe(PO4)2 was obtained using respectively the ceramic method, the Pechini method and the hydrothermal method. The low-temperature (Pechini and hydrothermal) methods yielded homogenous powders with a crystallite size up to 24 nm. The compound has a hexagonal structure with parameters of an elementary cell: a = b = 7.0468(8) ? and c = 6.4367(0) ?. The CaKCe(PO4)2 phosphate occurs in one polymorphic form. A phase equilibrium diagram of the CaKPO 4-CePO4 system has been established on the basis of XRD, DTA/DSC/TGA results. The initial phosphates were found to form one intermediate compound, CaKCe(PO4)2, with molar ratio CaKPO 4:CePO4 = 1:1, melting incongruently at a temperature of 1530 °C according to the reaction: CaKCe(PO4)2(cr) → CePO4(cr) + L. At a temperature of 1440 °C an eutectic was found to be present in the CaKPO4-CePO4 system at x(CePO4) = 0.25.

Epitaxial synthesis of uniform cerium phosphate one-dimensional nanocable heterostructures with improved luminescence

Uniform CePO4@LaPO4 and CePO4:Tb 3+@LaPO4 one-dimensional single-crystalline nanocable heterostructures with highly enhanced photoluminescent emission have been synthesized via a mild and simple hydrothermal approach. The resulting one-dimensional single-crystalline nanocable heterostructures have smooth and uniform LaPO4 sheaths, which is of great significance in effectively eliminating surface trap-states and suppressing the energy quenching in energy-transfer processes. The photoluminescence results for these one-dimensional nanocable heterostructures illustrate that the uniform LaPO 4 sheaths remarkably increase the luminescent efficiency. ? 2005 American Chemical Society.

Vapour phase O-alkylation of phenol over alkali promoted rare earth metal phosphates

The vapor phase synthesis of anisole by O-alkylation of phenol with methanol was studied over lanthanum, cerium, samarium, and antimony phosphate catalysts promoted with cesium hydroxide. The activity and selectivity trends on various catalysts followed the same pattern with temperature. The formation of some side products with traces of CO and CO2 were rarely noted at higher temperatures. The cesium promoted samarium phosphate showed maximum product yield (83%). The cesium promoter decreased the C-alkylation products and enhanced the O-alkylation product selectivity. The total amount of ammonia desorbed in the case of samarium was much higher than that of the Cs-Sm sample. A substantial decrease in the quantity of ammonia desorbed in the case of Cs-Sm catalyst indicated that the Cs promoter highly influenced the surface acidity of Sm-phosphate catalyst. Cs promoter had major influence on the strong acid sites of the catalyst.

Facile sonochemical synthesis and photoluminescent properties of lanthanide orthophosphate nanoparticles

Uniform lanthanide orthophosphate LnPO4 (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho) nanoparticles have been systematically synthesized via a facile, fast, efficient ultrasonic irradiation of inorganic salt aqueous solution under ambient conditi

Precipitation coating of rare-earth orthophosphates on woven ceramic fibers-effect of rare-earth cation on coating morphology and coated fiber strength

Monazite (La, Ce, Nd, and GdPO4) and xenotime (Tb, Dy, and YPO4) coatings were deposited on woven Nextel 610 and 720 fibers by heterogeneous precipitation from a rare-earth citrate/ phosphoric acid precursor. Coating phases and microstructure were characterized by SEMand TEM, and coated fiber strength was measured after heat treatment at 1200°C for 2 h. Coated fiber strength increased with decreasing ionic radius of the rareearth cation in the monazite and xenotime coatings, and correlates with the high-temperature weight loss and the densification rate of the coatings. Dense coatings with trapped porosity and high weight loss at a high temperature degrade fiber strength the most. The degradation is consistent with stress corrosion driven by thermal residual stress from coating precursor decomposition products trapped in the coating at a high temperature.

Hydrothermal synthesis and luminescent properties of novel ordered sphere CePO4 hierarchical architectures

The ordered-sphere CePO4 hierarchical architectures have been successfully synthesized by a simple hydrothermal method through the controlled growth of the CePO4 nanorods and self-assemble hierarchical structure under various reactio

Mixed valence cerium substitution in Gd2-xCexTi2O7+δ pyrochlores

Pyrochlore-type oxides having the formula Gd1.6Ce0.4Ti2O7+δδ have been synthesized by ceramic and co-precipitation methods and annealed at 1300 °C under different environments. Rietveld refinement of powder X-ray diffraction (XRD)patterns indicated that the products adopt the pyrochlore-type oxide structure with Ce ions substituting for Gd ions. Analysis of Ce 3d X-ray photoelectron spectroscopy (XPS)spectra confirmed the presence of both Ce3+ and Ce4+, which was corroborated by analysis of Ce L3-edge X-ray absorption near edge spectroscopy (XANES)spectra. Incorporation of Ce4+ imparts disorder on the Ti octahedra as observed by analysis of Ti K-edge XANES spectra. Due to the presence of Ce4+ in the A-site of the pyrochlore-type structure, oxygen is likely intercalated into the vacant anion 8b site to charge balance the system. This intercalation results in an increase of the average Ti coordination number from 6 to between 6 and 7, which leads to the formula unit being better represented as Gd1.6Ce0.4Ti2O7+δδ.

Ni/(rare earth phosphate) as a new effective catalyst for autothermal reforming of methane

The stability of metal phosphate during H2 reduction is one of the critical factors that determine the catalytic behavior of Ni/(metal phosphate) in CH4 autothermal reforming. Ni/(rare earth phosphate), particularly Ni/(Gd, Ce, or ErPO4), has been found to be a new family of effective catalysts. Copyright

Thermal conductivity of monazite-Type REPO4 (RE=La, Ce, Nd, Sm, Eu, Gd)

Low-thermal conductivity ceramics in monazite-type REPO4 (RE=La, Ce, Nd, Sm, Eu, Gd) ceramics are expected to have potential in structural (refractories, thermal insulator) and nuclear applications. To this end, the present study determines the

Preparation of two different crystal structures of cerous phosphate as solid acid catalysts: Their different catalytic performance in the aldol condensation reaction between furfural and acetone

Liquid fuel intermediates can be produced via aldol condensation reactions through furan aldehydes and ketones driven from biomass. It was found that cerous phosphate (CP) with two different crystal structures (hexagonal and monoclinic structure), which was tailored by different hydrothermal temperature (120 °C for the hexagonal structure and 180 °C for the monoclinic structure) and calcination temperature (900 °C for the monoclinic structure) as a solid acid catalyst, exhibit high catalytic performance in aldol condensation between furfural and acetone. The CP with hexagonal structure gave 89.1% conversion of furfural with 42% yield of 4-(2-furyl)-3-buten-2-one (FAc) and 17.5% of yield of 1,5-di-2-furanyl-1,4-pentadien-3-one (F2Ac), much higher than CP with monoclinic structure. However, both furfural conversion and aldol product yield increased from 82.3% to 96% and from 50.5% to 68.4%, respectively, for CP with the monoclinic structure after calcination owing to the higher amount of acid of catalyst after calcination but decreased continuously for CP with hexagonal structure after calcination because of its rapidly reduced BET surface area and total pore volume. The results indicated that calcination affects significantly the physical-chemical properties of CP catalysts, which influence subsequently the catalytic performance in the aldol condensation reaction. Recycling experiments showed that the catalytic performance after five number runs for CP with monoclinic structure after calcination was acceptable but was not ideal for CP with hexagonal structure owing to its poor hydrothermal stability.