An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xB.sub.2-C.sub.O.sub.3, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.

An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xB.sub.2-C.sub.O.sub.3, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.

According to this invention, a NiMoW trimetallic catalyst supported on porous alumina is obtained that shows very high activity for hydrotreating (HDT) of gasoils, particularly deep hydrodesulfurization (HDS) and hydrodesnitrogenation (HDN) of straight run gasoil in conditions of moderate pressure.

When the catalyst is applied to HDT of diesel, the NiMoW catalyst exhibits high catalytic activity. The content of sulfur and nitrogen in the resulting diesel can be reduced from 13,200 to 10 ppm and nitrogen from 360 ppm to less than 1 ppm, under moderate pressure, temperature and space-velocity (LHSV) similar to those of an industrial unit.

The catalytic composition, of trimetallic type, is prepared from an alumina support of high surface area to which a solution containing a metal precursor of an element of group VIB is added, followed by other solution that contains one of the precursors of the active metallic phase, a solution containing another of the precursors of the active metallic phase from group VIB, a metal promoter of group VIII and an additive promoter of acidity from group VB, and finally another solution containing a metal of group VIB, a metal of Group VIII and an organic compound, the used route promotes the preferential formation of well dispersed structures of the used metals on the support of porous alumina, less refractory to sulfidation, with high stacking and short lengths of metal sulfides formed in the resulting hydrodesulfurization catalyst. In the formulation, at least a percentage, but not all the Mo is replaced by W, in a Mo/W molar ratio of 0.6 to 2.0.

According to this invention, a NiMoW trimetallic catalyst supported on porous alumina is obtained that shows very high activity for hydrotreating (HDT) of gasoils, particularly deep hydrodesulfurization (HDS) and hydrodesnitrogenation (HDN) of straight run gasoil in conditions of moderate pressure.

When the catalyst is applied to HDT of diesel, the NiMoW catalyst exhibits high catalytic activity. The content of sulfur and nitrogen in the resulting diesel can be reduced from 13,200 to 10 ppm and nitrogen from 360 ppm to less than 1 ppm, under moderate pressure, temperature and space-velocity (LHSV) similar to those of an industrial unit.

The catalytic composition, of trimetallic type, is prepared from an alumina support of high surface area to which a solution containing a metal precursor of an element of group VIB is added, followed by other solution that contains one of the precursors of the active metallic phase, a solution containing another of the precursors of the active metallic phase from group VIB, a metal promoter of group VIII and an additive promoter of acidity from group VB, and finally another solution containing a metal of group VIB, a metal of Group VIII and an organic compound, the used route promotes the preferential formation of well dispersed structures of the used metals on the support of porous alumina, less refractory to sulfidation, with high stacking and short lengths of metal sulfides formed in the resulting hydrodesulfurization catalyst. In the formulation, at least a percentage, but not all the Mo is replaced by W, in a Mo/W molar ratio of 0.6 to 2.0.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50 C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50 C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A metal oxide catalyst, which has a bulk composition represented by formula (1) below and which is used to produce a conjugated diolefin by an oxidative dehydrogenation reaction between a monoolefin, having 4 or more carbon atoms, and molecular oxygen, wherein standard deviation obtained by dividing a ratio of Bi molar concentration relative to Mo molar concentration at the surface of a catalyst particle by a ratio of the Bi molar concentration relative to the Mo molar concentration in a catalyst bulk is 0.3 or less.

Mo.sub.12Bi.sub.pFe.sub.qA.sub.aB.sub.bC.sub.cD.sub.dE.sub.eF.sub.fO.sub.x(1)

(In the formula, A is at least one type of element selected from the group consisting of Ni and Co, B is at least one type of element selected from among alkali metal elements, C is at least one type of element selected from the group consisting of Mg, Ca, Sr, Ba, Zn and Mn, D is at least one type of rare earth element, E is at least one type of element selected from the group consisting of Cr, In and Ga, F is at least one type of element selected from the group consisting of Si, Al, Ti and Zr, O is oxygen, p, q, a, b, c, d, e, f and x denote the number of atoms of Bi, Fe, A, B, C, D, E, F and oxygen, respectively, relative to 12 Mo atoms, and are such that 0.1p5, 0.5q8, 0a10, 0.02b2, 0c5, 0d5, 0e5 and 0f200, and x is the number of oxygen atoms required to satisfy valency requirement of other elements present.)

The present invention provides a method for increasing the UV transmittance of ethylene glycol. The method uses an ethylene glycol solution and hydrogen as raw materials, and uses an alloy catalyst comprising nickel, one or more rare-earth elements, tin, and aluminum, the contents thereof in parts by weight being 10-90, 1-5, 1-60, and 5-9, respectively. The method of the present invention uses an inexpensive, stable-in-aqueous-phase, carrier-free alloy as a catalyst, and continuously adds hydrogen to reduce unsaturated impurities in ethylene glycol. In application of the method of the present invention in continuous industrial-scale production, the use of this type of alloy catalyst could be especially significant for the achievement of long-term system stability and control of production costs.

The present invention relates to a method for producing unsaturated aldehydes and unsaturated carboxylic acids. According to the present invention, a method for producing unsaturated aldehydes and unsaturated carboxylic acids which can impart activity and control temperature independently in fixed catalyst layer zones in a shell-and-tube reactor, thereby exhibiting improved yield and operation stability, is provided.

The present invention relates to a method for producing unsaturated aldehydes and unsaturated carboxylic acids. According to the present invention, a method for producing unsaturated aldehydes and unsaturated carboxylic acids which can impart activity and control temperature independently in fixed catalyst layer zones in a shell-and-tube reactor, thereby exhibiting improved yield and operation stability, is provided.