Methods are provided for forming noble metal catalysts comprising both platinum and a second Group VIII metal, such as palladium, with improved aromatic saturation activity. Instead of impregnating a catalyst with both platinum and another Group VIII metal at the same time, a sequential impregnation can be used, with the Group VIII metal being impregnated prior to platinum. It has been discovered that by forming a Group VIII metal-impregnated catalyst first, and then impregnating with platinum, the distribution of platinum throughout the catalyst can be improved. The improved distribution of platinum can result in a catalyst with enhanced aromatic saturation activity relative to a catalyst with a similar composition formed by simultaneous impregnation.

A catalyst system for dewaxing of a hydrocarbon feedstock comprising at least two catalytic sections, the first section comprising a first dewaxing catalyst and a subsequent section comprising a second dewaxing catalyst, wherein the first dewaxing catalyst is a ZSM-12 zeolite based catalyst and the second dewaxing catalyst is a EU-2 and/or ZSM-48 zeolite based catalyst. The catalyst system displays enhanced performance when compared to systems containing either ony ZSM-12 based catalyst or EU-2/ZSM-48 based catalyst only.

Provided herein is a unique process that prepares a saturated hydrocarbon mixture with well-controlled structural characteristics that address the performance requirements driven by the stricter environmental and fuel economy regulations for automotive engine oils. The process allows for the branching characteristics of the hydrocarbon molecules to be controlled so as to consistently provide a composition that has a surprising CCS viscosity at 35 C. (ASTM D5329) and Noack volatility (ASTM D5800) relationship. The process comprises providing a specific olefinic feedstock, oligomerizing in the presence of a BF.sub.3 catalyst, and hydroisomerizing in the presence of a noble-metal impregnated, 10-member ring zeolite catalyst.

Methods are provided for using a molecular sieve catalyst for dewaxing formed using a synthesis mixture comprising a morphology modifier. The catalyst may be used, for example, for production of a lubricant base stock. For example, ZSM-48 crystals formed using the morphology modifier (and/or formulated catalysts made using such crystals) can have an increased activity and/or can provide an improved yield during catalytic dewaxing of lubricant base stocks.

The present disclosure relates to a precursor for a catalytically active material or a catalytically active material comprising platinum, a molecular sieve and a metal oxide support, characterized in at least 80%, 90% or 95% of said platinum being dispersed on said molecular sieve and at least 80%, 90% or 95% of said platinum being dispersed in clusters having a size below 2 nm or 1 nm, as well as a method of producing such materials and process for hydroisomerization involving such materials. The disclosure has the associated benefit of such a catalytically active material being highly active and selective towards hydroisomerization.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of a first and a second catalyst composition under conversion conditions effective to produce said lighter aromatic products comprising benzene, toluene and xylene. In the process, the C.sub.8+ aromatic hydrocarbons are dealkylated to form C.sub.6-C.sub.7 aromatic hydrocarbon and the C.sub.2+ olefins formed are saturated. The remaining C.sub.8+ aromatic hydrocarbons are transalkylated with the C.sub.6-C.sub.7 aromatic hydrocarbon. The first and second catalyst compositions each comprise a zeolite, a first metal, and optionally a second metal, and are treated with a source of sulfur and/or a source of steam.

A process for reducing haze in a heavy base oil includes: obtaining a first effluent oil by contacting a hydrocarbon feedstock with a first catalyst including a zeolite of the ZSM-12 family; and obtaining a second effluent oil by contacting the first effluent oil with a second catalyst including a zeolite of the ZSM-48 family. A hydroisomerization catalyst system having reduced haze includes: a first catalytic region having a first catalyst disposed therein, the first catalyst including a zeolite of the ZSM-12 family; and a second catalytic region having a second catalyst disposed therein, the second catalyst including a zeolite of the ZSM-48 family. The first catalytic region is disposed upstream of the second catalytic region.

A hydrocarbon conversion catalyst composition which comprises ZSM-48 and/or EU-2 zeolite particles and refractory oxide binder essentially free of alumina in which the average aluminium concentration of the ZSM-48 and/or EU-2 zeolite particles is at least 1.3 times the aluminium concentration at the surface of the particles, processes for preparing such catalyst compositions and processes for converting hydrocarbon feedstock with the help of such compositions.

A hydrocarbon conversion catalyst composition which comprises dealuminated ZSM-48 and/or EU-2 zeolite and a refractory oxide binder essentially free of alumina, processes for preparing such composition and processes for converting hydrocarbon feedstock with the help of such compositions.