Embodiments of processes and multiple-stage catalyst systems for producing propylene comprising introducing a hydrocarbon stream comprising 2-butene to an isomerization catalyst zone to isomerize the 2-butene to 1-butene, passing the 2-butene and 1-butene to a metathesis catalyst zone to cross-metathesize the 2-butene and 1-butene into a metathesis product stream comprising propylene and C.sub.4-C.sub.6 olefins, and cracking the metathesis product stream in a catalyst cracking zone to produce propylene. The isomerization catalyst zone comprises a silica-alumina catalyst with a ratio by weight of alumina to silica from 1:99 to 20:80. The metathesis catalyst comprises a mesoporous silica catalyst support impregnated with metal oxide. The catalyst cracking zone comprises a mordenite framework inverted (MFI) structured silica catalyst.

The present invention relates to a porous iron oxide-zirconia composite catalyst, a preparation method thereof, and a method for producing alcohol using the same, and the iron oxide-zirconia composite catalyst having a porous structure may produce alcohol at low cost by carrying out an excellent methane reforming reaction even under room temperature and room pressure conditions through an electrochemical reaction.

A process is used for oligomerizing C2- to C8-olefins in several reaction stages in which the starting mixture and the respective outputs from the reaction stages are separated and are fed to different reaction stages.

Embodiments of methods of synthesizing a metathesis catalyst system, which include impregnating tungsten oxide on silica support in the presence of a precursor to produce a base catalyst; calcining the base catalyst; impregnating a metal oxide co-catalyst comprising a metal oxide onto the surface of the base catalyst to produce a doped catalyst; and calcining the doped catalyst to produce a metathesis catalyst system. Further embodiments of processes for the production of propylene, which include contacting a hydrocarbon feedstock comprising a mixture of 1-butene and 2-butene with embodiments of the metathesis catalyst system to produce, via metathesis conversion, a product stream comprising propylene.

Embodiments of methods of synthesizing a metathesis catalyst system, which include impregnating tungsten oxide on silica support in the presence of a precursor to produce a base catalyst; calcining the base catalyst; dispersing a solid metal-based co-catalyst onto the surface of the base catalyst to produce a doped catalyst; and calcining the doped catalyst to produce a metathesis catalyst system. Further embodiments of processes for the production of propylene, which include contacting a hydrocarbon feedstock comprising a mixture of 1-butene and 2-butene with embodiments of the metathesis catalyst system to produce, via metathesis conversion, a product stream comprising propylene.

Embodiments of methods of synthesizing a metathesis catalyst system, which include impregnating tungsten oxide on silica support in the presence of a precursor to produce a base catalyst; calcining the base catalyst; dispersing a solid metal-based co-catalyst onto the surface of the base catalyst to produce a doped catalyst; and calcining the doped catalyst to produce a metathesis catalyst system. Further embodiments of processes for the production of propylene, which include contacting a hydrocarbon feedstock comprising a mixture of 1-butene and 2-butene with embodiments of the metathesis catalyst system to produce, via metathesis conversion, a product stream comprising propylene.

A pre-catalyst composition comprising a) a silica support comprising silica wherein an amount of silica ranges from about 70 wt. % to about 95 wt. % based upon a total weight of the silica support, b) a chromium-containing compound wherein an amount of chromium ranges from about 0.1 wt. % to about 5 wt. % based upon the amount of silica, c) a titanium-containing compound wherein an amount of titanium ranges from about 0.1 wt. % to about 20 wt. % based upon the amount of silica, d) a carboxylic acid wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid ranges from about 1:1 to about 1:10, and e) a nitrogen-containing compound with a molecular formula containing at least one nitrogen atom wherein an equivalent molar ratio of titanium-containing compound to nitrogen-containing compound ranges from about 1:0.5 to about 1:10.

Disclosed is a catalyst comprising: a composition having a formula BN.sub.xM.sub.yO.sub.z wherein B represents boron, N represents nitrogen, M comprises a metal or metalloid, and O represents oxygen, x ranges from 0 to 1, y ranges from 0.01 to 5.5; and z ranges from 0 to 16.5. The catalyst may be suitable for converting alkanes to olefins.

A catalyst includes a support, where the support includes an external surface, about 60 wt % to about 99 wt % silica, and about 1.0 wt % to about 5.0 wt % alumina. A catalytic layer is disposed within the support adjacent to the external surface, where the catalytic layer further includes Pd, Au, and potassium acetate (KOAc). In the catalyst, (a) the KOAc is from about 60 kg/m.sup.3 to about 150 kg/m.sup.3 of the catalyst; or (b) the catalytic layer has an average thickness from about 50 m to about 150 m; or (c) both (a) and (b). The catalyst also possesses a Brunauer-Emmett-Teller surface area of about 130 m.sup.2/g to about 300 m.sup.2/g and a geometric surface area per packed bed volume from about 550 m.sup.2/m.sup.3 to about 1500 m.sup.2/m.sup.3. The catalyst is highly active for the synthesis of vinyl acetate monomer and exhibits a high selectivity for vinyl acetate monomer.

Monolithic composite photocatalysts for fluid purification, chemical transformations, and surface sterilization are disclosed. The monolithic composite photocatalysts comprise a photoactive nanocrystal component and a non-photoactive porous support. Photocatalytic fluid purification systems that contact an impurity-containing fluid with the subject monolithic composite photocatalysts are also disclosed.