A modified Y-type molecular sieve has a unit cell size of 2.420-2.440 nm. It contains a phosphorus content of 0.05-6%, a RE.sub.2O.sub.3 content of 0.03-10%, and an alumina content of less than 22%, and a specific hydroxyl nest concentration of less than 0.35 mmol/g and more than 0.05 mmol/g. The modified Y-type molecular sieve is used as the active component in a catalytic cracking catalyst. The catalytic cracking catalyst maintains a stable activity for a long time, effectively controls the coke yield and increases the heavy oil utilization.

The invention includes an additive for maximizing production of olefins. The additive comprises a ZSM-5 molecular sieve, at least one inorganic oxide, and phosphorus oxide. The ZSM-5 molecular sieve has iron in the framework, and the additive comprises at least 0.5 weight percent iron, as measured as iron oxide, in the molecular sieve framework. The additive is useful for maximizing production of olefins in a FCC process.

The invention includes an additive for maximizing production of olefins. The additive comprises a ZSM-5 molecular sieve, at least one inorganic oxide, and phosphorus oxide. The ZSM-5 molecular sieve has iron in the framework, and the additive comprises at least 0.5 weight percent iron, as measured as iron oxide, in the molecular sieve framework. The additive is useful for maximizing production of olefins in a FCC process.

A hydrotreating catalyst includes a hydrogenation active metal supported on a alumina-phosphorus support and satisfies: a specific surface area being 100 m.sup.2/g or more; a total pore volume measured by mercury intrusion being in a range 0.80-1.50 ml/g; a maximum value of pore distribution being present in a pore diameter range 10-30 nm; a ratio of a pore volume of pores with a pore diameter within a range of ±2 nm of a pore diameter at the maximum value to a pore volume of pores with a pore diameter in a range 5-100 nm being 0.40 or less; a pressure capacity being 10 N/mm or more; 0.4-10.0 mass % of phosphorus being contained in the catalyst in terms of P.sub.2O.sub.5 concentration based on a total amount of the catalyst; and a hydrogenation active metal being at least one metal selected from metals of VIA and VIII groups of the periodic table.

Process for the preparation of a catalyst and a catalyst comprising the use of more than one silica source is provided herein. Thus, in one embodiment, the invention provides a particulate FCC catalyst comprising about 5 to about 60 wt % one or more zeolites, about 15 to about 35 wt % quasicrystalline boehmite (QCB), about 0 to about 35 wt % microcrystalline boehmite (MCB), greater than about 0 to about 15 wt % silica from sodium stabilized basic colloidal silica, greater than about 0 to about 30 wt % silica from acidic colloidal silica or polysilicic acid, and the balance clay and the process for making the same. This process results in attrition resistant catalysts with a good accessibility.

Process for the preparation of a catalyst and a catalyst comprising the use of more than one silica source is provided herein. Thus, in one embodiment, the invention provides a particulate FCC catalyst comprising about 5 to about 60 wt % one or more zeolites, about 15 to about 35 wt % quasicrystalline boehmite (QCB), about 0 to about 35 wt % microcrystalline boehmite (MCB), greater than about 0 to about 15 wt % silica from sodium stabilized basic colloidal silica, greater than about 0 to about 30 wt % silica from acidic colloidal silica or polysilicic acid, and the balance clay and the process for making the same. This process results in attrition resistant catalysts with a good accessibility.

A catalyst for hydrocarbon catalytic cracking of the invention contains: a catalyst (a) containing faujasite-type zeolite (A) having a unit cell size in a range of 2.435 nm to 2.455 nm, a matrix component, and rare earths; and a catalyst (b) containing faujasite-type zeolite (B) having a unit cell size in a range of 2.445 nm to 2.462 nm, a matrix component, phosphorus, and magnesium.

A catalyst for hydrocarbon catalytic cracking of the invention contains: a catalyst (a) containing faujasite-type zeolite (A) having a unit cell size in a range of 2.435 nm to 2.455 nm, a matrix component, and rare earths; and a catalyst (b) containing faujasite-type zeolite (B) having a unit cell size in a range of 2.445 nm to 2.462 nm, a matrix component, phosphorus, and magnesium.

An improved process and catalyst composition for cracking hydrocarbons in a fluidized cracking process are disclosed. The process employs circulating inventory of a regenerated cracking having a minimal carbon content. The regenerated catalyst comprises a catalyst/additive composition which contains a pentasil zeolite, iron oxide, and a phosphorous compound. In accordance with the present disclosure, the catalyst/additive contains controlled amounts of iron oxide which is maintained in an oxidized state by maintaining low amounts of carbon on the regenerated catalyst inventory. In this manner it was discovered that the catalyst composition greatly enhances the production and selectivity of light hydrocarbons, such as propylene.

A process may include contacting an oxygen-containing, halogenide-containing or sulphur-containing organic feedstock in an XTO reactor with a catalyst composite under conditions effective to convert the oxygen-containing, halogenide-containing or sulphur-containing organic feedstock to olefin products. The catalyst composite may include at least 10 weight percent of a modified molecular sieve. The modified molecular sieve may include at least 0.05 weight percent of an alkaline earth metal or a rare earth metal based on a weight of the modified molecular sieve. The modified molecular sieve may include at least 0.3 weight percent of P based on the weight of the modified molecular sieve.