Abstract: Self-promoted molybdenum and tungsten sulfide hydrotreating catalysts are prepared by heating one or more water soluble catalyst precursors in a non-oxidizing atmosphere in the presence of sulfur at a temperature of at least about 200.degree. C. The precursors are (Cr.sub.x M.sub.1-x L)[Mo.sub.y W.sub.1-y O.sub.4 ].sub.1+.5x wherein M is a divalent promoter metal selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn and mixtures thereof, x is any value from about 0.2 to 1, y is any value from 0 to 1, and wherein L is a nitrogen-containing, neutral multidentate, chelating ligand. In a preferred embodiment the lligand L will comprise one or more chelating alkyl di- or triamines and the non-oxidizing atmosphere will comprise H.sub.2 S.

Abstract: This invention relates to the preparation and use of catalysts useful for hydroprocessing processes, such as hydrotreating, wherein said catalysts are formed by heating, at elevated temperature, in the presence of sulfur and under oxygen-free conditions, a composite of support material and one or more catalyst precursor salts containing a thiometallate anion of Mo, W or mixture thereof and a cation comprising one or more divalent promoter metals at least one of which is iron, wherein said promoter metal or metals are chelated by at least one neutral, nitrogen-containing polydentate ligand, and wherein said additional divalent promoter metal, if any, is selected from the group consisting of Ni, Co, Mn, Zn, Cu and mixture thereof.

Abstract: Supported, hydroprocessing catalysts comprising a sulfide of (i) trivalent chromium, (ii) Mo, W or mixture thereof and (iii) at least one metal selected from the group consisting of Ni, Co, Mn, Cu, Zn and mixture thereof and mixture thereof with Fe. These catalysts are made by compositing a preselected quantity of support material with a precursor comprising a mixture of (i) hydrated oxide of trivalent chromium and (ii) a salt containing a thiometallate anion of Mo or W and a cation comprising at least one divalent promoter metal chelated by at least one, neutral, nitrogen-containing polydentate ligand and heating the composite in the presence of sulfur and hydrogen in an oxygen-free atmosphere. These catalysts have been found to be useful hydrotreating catalysts having nitrogen removal activity superior to that of commercial catalysts such as sulfided cobalt-molybdate on alumina.

Abstract: Improved coatings for high temperature solar collectors comprise thermally stable inorganic oxides selected from ferrites, metal oxides and mixtures thereof having solar absorptances greater than 0.9 at wavelengths ranging from about 0.35 to 3.0 microns. The coatings can be applied to a heat transfer surface by painting an organic silicate dispersion of the optically active material onto the substrate and thereafter curing the silicate binder.

Abstract: Improved coatings for high temperature solar collectors comprise thermally stable inorganic oxides selected from ferrites, metal oxides and mixtures thereof having solar absorptances greater than 0.9 at wavelengths ranging from about 0.35 to 3.0 microns. The coatings can be applied to a heat transfer surface by painting an organic silicate dispersion of the optically active material onto the substrate and thereafter curing the silicate binder.