The present invention relates to a process for modifying a layered double hydroxide (LDH), the process comprising, a. providing a material comprising a layered double hydroxide of formula: [M.sup.z+.sub.1-xM.sup.y+.sub.x(OH).sub.2].sup.q+(X.sup.n).sub.q/n.bH.sub.2O wherein M and M are metal cations, z is 1 or 2, x is 0.1 to 1, b is 0 to 5, y is 3 or 4, X is an anion, n is 1 to 3 and q is determined by x, y and z, b. optionally washing the material at least once with a mixture of water and a mixing solvent miscible with water, and c. washing the material obtained in step a or b at least once with at least one first solvent, the first solvent being miscible with water and having a solvent polarity P.

A luminescent composition of matter is characterized by the formula REM.sub.2+xE.sub.y, where RE may be one or more Rare Earth elements (for example, Eu or Gd), M may be one or more elements selected from the group Al, Ga, B, In, Sc, Lu, and Y; E is one or more elements selected from the group S, Se, O, and Te; x is greater than zero; and y has the value that achieves charge balance in the formula assuming that E has a charge of 2.

A luminescent composition of matter is characterized by the formula REM.sub.2+xE.sub.y, where RE may be one or more Rare Earth elements (for example, Eu or Gd), M may be one or more elements selected from the group Al, Ga, B, In, Sc, Lu, and Y; E is one or more elements selected from the group S, Se, O, and Te; x is greater than zero; and y has the value that achieves charge balance in the formula assuming that E has a charge of 2.

The present invention relates to heterogeneous acid catalysts comprising or consisting of mixed metal salts, of lithium and aluminum phosphates and sulfates, and combinations with metallic cations, such as magnesium, titanium, zinc, zirconium and gallium, to provide adequate Lewis acidity; organic or inorganic porosity promoters, such as polysaccharides; and agglomerates, such as clays, kaolin and metal oxides of the type M.sub.xO.sub.y, where; M=Al, Mg, Sr, Zr or Ti, and other metals of groups IA, IIA and IVB, x=1 or 2 and y=2 or 3, for the formation of particles. A process is disclosed for obtaining from the catalyst by the hydrolysis of aluminum lithium hydride with water and oxygenated solvent, such as an ether. The catalysts are used in batch reactor and continuous flow systems in reactions that require moderate Lewis acidity, such as refining, petrochemical and general chemistry, including the transesterification of glycerides to produce alkyl esters.

Methods of removing one or more oxyanions from an aqueous fluid can comprise increasing the pH of an aqueous fluid containing one or more oxyanions and contacting the aqueous fluid with aluminum metal.

The present invention relates to a process A process for modifying a layered double hydroxide (LDH), the process comprising, a. providing a material comprising a layered double hydroxide of formula: [M.sup.z+.sub.1-xM.sup.y+.sub.x(OH).sub.2].sup.q+(X.sup.n).sub.q/n.bH.sub.2O wherein M and M are metal cations, z is 1 or 2, x is 0.1 to 1, b is 0 to 5, y is 3 or 4, X is an anion, n is 1 to 3 and q is determined by x, y and z, b. optionally washing the material at least once with a mixture of water and a mixing solvent miscible with water, and c. washing the material obtained in step a or b at least once with at least one first solvent, the first solvent being miscible with water and having a solvent polarity P