A method of preparing hydrodesulfurization catalysts having cobalt and molybdenum sulfide deposited on a support material containing mesoporous silica. The method utilizes a sulfur-containing silane that dually functions as a silica source and a sulfur precursor. The method involves an one-pot strategy for hydrothermal treatment and a single-step calcination and sulfidation procedure. The application of the hydrodesulfurization catalysts in treating a hydrocarbon feedstock containing sulfur compounds to produce a desulfurized hydrocarbon stream is also specified.

An ethylbenzene dealkylation catalyst composition comprising a ZSM-5 type zeolite as a carrier component, wherein said zeolite has been synthesized from an aqueous reaction mixture comprising one or more alumina sources, one or more silica sources, one or more alkali sources, and one or more primary and/or secondary amines and wherein the ZSM-5 type zeolite has a number average crystallite size in the range of from 1 to 10 μm and a molar silica-to-alumina ratio (SAR) in the range of from 30 to 70; a method for reducing xylene losses in an ethylbenzene dealkylation process, said method comprising conducting the ethylbenzene dealklylation process in the presence of the afore-mentioned catalyst composition; and a process for the dealkylation of ethylbenzene, which process comprises contacting, in the presence of hydrogen, a feedstock which comprises ethylbenzene with said catalyst composition.

The disclosure discloses a catalyst capable of simultaneously removing COS and H.sub.2S in garbage gasification and a preparation method thereof, and belongs to the technical field of preparation of desulfurization catalysts. The method includes the following steps: pretreating an SBA-15 molecular sieve with a templating agent unremoved, which primarily includes the steps of removing the templating agent and introducing halogen atoms to modify the molecular sieve; then synthesizing an active component solution; and finally introducing active components into channels of the pretreated molecular sieve via surface tension by adopting an impregnation method, performing washing and drying, and performing calcining under an N.sub.2 atmosphere, so as to obtain the catalyst. An H.sub.2S and COS removal experiment is performed on the catalyst prepared according to the present disclosure under a simulated garbage gasification atmosphere, and a desulfurization experiment is performed as a control, so as to evaluate the desulfurization efficiency. The catalyst prepared according to the present disclosure can load the active components in fixed positions inside and outside the channels, and the components are easy to obtain, thereby having the advantages of low cost and good desulfurization effects.

A NaY molecular sieve with an aluminum-rich surface is prepared using a process that includes the steps of: a. mixing a directing agent and a first silicon source to obtain a first mixture, wherein the directing agent has a molar composition of Na.sub.2O:Al.sub.2O.sub.3:SiO.sub.2:H.sub.2O=(6-25):1:(6-25):(200-400); b. mixing the first mixture obtained in the step a with a second silicon source, an aluminum source and water to obtain a second mixture; c. carrying out hydrothermal crystallization on the second mixture obtained in the step b, and collecting a solid product. Calculated as SiO.sub.2, the weight ratio of the first silicon source to the second silicon source is 1:(0.01-12). The NaY molecular sieve has larger aluminum distribution gradient from the surface to the center of the particle than the conventional molecular sieve.

A modified Y-type molecular sieve has a modifying metal content of about 0.5-6.3 wt % calculated on the basis of an oxide of the modifying metal and a sodium content of no more than about 0.5 wt % calculated on the basis of sodium oxide. The modifying metal is magnesium and/or calcium. The modified Y-type molecular sieve has a proportion of non-framework aluminum content to the total aluminum content of no more than about 20%, a total pore volume of about 0.33-0.39 ml/g, a proportion of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 10-25%, a lattice constant of about 2.440-2.455 nm, a lattice collapse temperature of not lower than about 1040° C., and a ratio of B acid to L acid in the total acid content of no less than about 2.30.

A modified Y-type molecular sieve has a rare earth content of about 4% to about 11% by weight on the basis of the oxide, a phosphorus content of about 0.05% to about 10% by weight on the basis of P.sub.2O.sub.5, a sodium content of no more than about 0.5% by weight on the basis of sodium oxide, and an active element content of about 0.1% to about 5% by weight on the basis of the oxide, with the active element being gallium and/or boron. The modified Y-type molecular sieve has a total pore volume of about 0.36 mL/g to about 0.48 mL/g, a percentage of the pore volume of secondary pores having a pore size of 2-100 nm of about 20% to about 40%; a lattice constant of about 2.440 nm to about 2.455 nm, and a lattice collapse temperature of not lower than about 1060° C.

The present invention relates to a preparation method for an olefin epoxidation catalyst, comprising: (1) preparing a titanium-silicon gel; (2) performing pore-enlarging treatment to the titanium-silicon gel by using organic amine or liquid ammonia, and drying, calcinating to obtain a titanium-silicon composite oxide; (3) optionally performing alcohol solution of organic alkali metal salt treatment; and (4) optionally performing gas-phase silanization treatment. The catalyst prepared by the method of the present invention has adjustable variability for pore size, so that the activity thereof for epoxidation reactions of the olefin molecules with different dynamic diameters is higher; the surface acidity of the catalyst can be reduced effectively through two-step modification to the catalyst, so that the catalyst has higher selectivity for epoxidation product.

A modified Y-type molecular sieve having a calcium content of about 0.3-4 wt % calculated on the basis of calcium oxide, a rare earth content of about 2-7 wt % calculated on the basis of rare earth oxide, and a sodium content of no more than about 0.5 wt % calculated on the basis of sodium oxide. The modified Y-type molecular sieve has a total pore volume of about 0.33-0.39 ml/g, a proportion of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 10-25%, a lattice constant of about 2.440-2.455 nm, a proportion of non-framework aluminum content to the total aluminum content of no more than about 20%, a lattice collapse temperature of not lower than about 1050° C., and a ratio of B acid to L acid in the total acid content of no less than about 2.30.

A method of preparing hydrodesulfurization catalysts having cobalt and molybdenum sulfide deposited on a support material containing mesoporous silica. The method utilizes a sulfur-containing silane that dually functions as a silica source and a sulfur precursor. The method involves an one-pot strategy for hydrothermal treatment and a single-step calcination and sulfidation procedure. The application of the hydrodesulfurization catalysts in treating a hydrocarbon feedstock containing sulfur compounds to produce a desulfurized hydrocarbon stream is also specified.

Embodiments of catalyst systems and methods of synthesizing catalyst systems are provided. The catalyst system may include a core comprising a zeolite; and a shell comprising a microporous fibrous silica. The shell may be in direct contact with at least a majority of an outer surface of the core. The catalyst system may have a Si/Al molar ratio greater than 5. At least a portion of the shell may have a thickness of from 50 nanometers (nm) to 360 nm.