Abstract: A catalyst for the hydrotreatment of heavy hydrocarbon oils, which is prepared by supporting more than 2% by weight of VS.sub.x, wherein x represents about 1.1-1.59 in terms of an atomic ratio of S/V, on a substrate composed of a clay mineral which consists of magnesium silicate as a major component and having a double-chain structure and a process for preparing the catalyst are provided. The catalyst is prepared by accumulating the VS.sub.x on the substrate using a heavy hydrocarbon oil which contains particularly large amounts of vanadium and sulfur.

Abstract: There is disclosed a method for decreasing catalyst coking and extending the usable catalyst life by pre-treatment of the catalyst with steam and/or a phosphorus-containing compound. Catalysts benefiting from such pre-treatment comprise crystalline zeolites characterized by a silica to alumina mole ratio of at least 12 and a constraint index, as herein defined, within the approximate range of 1 to 12.

Abstract: There is disclosed a catalytic composition represented by the formula:(Mo).sub.a (W).sub.b (Bi).sub.c (Pb).sub.d (Sb).sub.e (A).sub.f (B).sub.g (C).sub.h (P).sub.m (O).sub.nin which A is iron and/or chromium, B is cerium and/or magnesium and C is potassium and/or lithium; and a, b, c, d, e, f, g, h, m and n stand for the numbers of atoms for molybdenum, tungsten, bismuth, lead, antimony, A, B, C, phosphorus and oxygen elements respectively, wherein, given that a+b=12,0.ltoreq.b.ltoreq.7, 0.4.ltoreq.c.ltoreq.7, 2.ltoreq.d.ltoreq.12,0.1/22.ltoreq.e/a.ltoreq.25/22, 0.05/22.ltoreq.f/a.ltoreq.3/22,0.ltoreq.g/a.ltoreq.2/22, 0.ltoreq.h/a.ltoreq.3/22,0.ltoreq.m/a.ltoreq.7/22, andn is the numbers of oxygen necessary to satisfy the valences of atoms for the individual constituent elements other than oxygen.

Abstract: The invention relates to a method for preparing a crystalline aluminosilicate having a high silica to alumina molar ratio and an X-ray diffraction pattern substantially the same as that of ZSM-5 zeolite which method comprises mixing a source of silica, a source of alumina, a source of alkali metal, water and at least one alkanolamine according to Formula (I): ##STR1## wherein any two of R.sup.1, R.sup.2 and R.sup.3 are independently alkylol groups and the remaining one of R.sup.1, R.sup.2 and R.sup.3 is a hydrogen atom or all of R.sup.1, R.sup.2 and R.sup.3 are independently alkylol group, the alkylol groups being --CH.sub.2 --R--OH, wherein R is --CH.sub.2 --, --CH.sub.2 CH.sub.2 --, or --CH(CH.sub.3)--, the ratio of said source of silica to said source of alumina being at least 20:1 based on the equivalent moles of silica and alumina in said respective sources, maintaining said mixture at a temperature above about 120.degree. C. and recovering the crystalline aluminosilicate formed.