Compounds praseodymium

Some rare earth compounds are used in glassmaking. Cerium is the most abundant, and its compounds are used to polish glass. Lanthanum compounds are used in making glass lenses, and praseodymium compounds color glass green. 

Table I. Oxidative Methane Coupling over Praseodymium Compounds...

The Surface Properties of the Praseodymium Compound. Although the efficiency of catalysts in methane conversion has been ascribed to a variety of properties, a number of researchers have demonstrated the importance of basicity of the catalysts employed in this process (14-16). Thus estimates of basicity, such as may be obtained from the adsorption of carbon dioxide, are of some value in characterizing the catalysts. It is obvious that the surface state of a working catalyst at 750°C is different from that at room temperature. However, measurements of the adsorption of carbon dioxide at the latter temperature provide semiquantitative information on sites capable of donating electrons. 

Asprey, L.B., J.S. Colman and M.J. Reisfeld, 1967, Preparation, Structure and Spectra of some Tetravalent Praseodymium Compounds, in Gould, R.F., ed., Advances in Chemistry Series No. 71 (American Chemical Society, Washington), pp. 122-126. 

Surprisingly (he praseodymium compound is again ferromagnetic In Pr2Sb a Curie temperature Tc = 62 K was observed (Bucher, 1976). 

Lanthanide nitrates are soluble in LiNOs-KNOs eutectic and the complex nitrates K3R2(N03)9 (R = Pr, Nd, and Sm) can be isolated (Carnall et al., 1973). The praseodymium compound is surrounded by twelve oxygen atoms belonging to six nitrate ions and is in the form of a distorted icosahedron. 

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