Disclosed herein are a chromium compound represented by Formula 1a or 1b and a catalyst system including the same, exhibiting superior catalytic activity in an olefin trimerization reaction:
[{CH.sub.3(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CO.sub.2}.sub.2Cr(OH)][Formula 1a]
[{CH.sub.3CH.sub.2CH(CH.sub.2CH.sub.3)CO.sub.2}.sub.2Cr(OH)].[Formula 1b]

Disclosed are a novel catalyst system which is a catalyst system for selectively oligomerizing olefin including ethylene and may trimerize and tetramerize olefin, different from the catalyst system for olefin oligomerization reported until now, and a method for preparing an olefin oligomer using same. The present invention provides a catalyst system for olefin oligomerization, including a ligand compound represented by Formula 1; a chromium compound; and a metal alkyl compound, and a method for preparing an olefin oligomer using same.

The present application is directed to a method for the conversion of nitrous acid to dinitrogen gas. In particular, the present application relates to a method for the conversion of nitrous acid to dinitrogen gas by contacting the nitrous acid with an amine-functionalized metal organic framework.

We provide a process for regenerating a used acidic ionic liquid catalyst which has been deactivated by conjunct polymers in a reactor, by removing at least 57 wt % of the conjunct polymers originally present in the used acidic ionic liquid catalyst in a separate regeneration reactor, so as to increase the activity of the catalyst. We also provide a regenerated used acidic ionic liquid catalyst having increased activity.

In one aspect, the present invention provides catalysts for the carbonylation of heterocycles. The inventive catalysts feature metal-ligand complexes having cationic functional groups tethered to the ligand, wherein the tethered cationic groups are associated with anionic metal carbonyl species. The invention also provides methods of using the inventive catalysts to affect the ring opening carbonylation of epoxides.

A method for manufacturing a modified porous organic framework includes steps as follows. A mixed solution is provided. The mixed solution includes a porous organic framework, a plurality of group donors and a solvent. The porous organic framework includes a plurality of first ligands. Each of the first ligands includes at least one tetrazine group. Each of the group donors includes a reactive group and a modifying group covalently connected with each other. The reactive groups are alkenyl groups, alkynyl groups, aldehyde groups, ketone groups or a combination thereof. A modifying step is conducted, wherein at least one of the reactive groups of the group donors is reacted with at least one of the tetrazine groups of the first ligands, so that at least one of the modifying groups of the group donors is covalently connected with the porous organic framework, whereby the modified porous organic framework is obtained.

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with catalytic activity tethered to a ligand that is coordinated to the active metal center of the complex.

A process for the preparation of pre-activated or pre-polymerized catalysts made from or containing a solid catalyst component made from or containing Ti, Mg, and halogen is disclosed. The resulting catalyst is protected from the release of flammable gases in contact with water. The process includes the steps of (a) a reaction step for yielding a catalyst precursor; (b) a reaction step in which the catalyst precursor is reacted with an organoaluminum compound for yielding a modified-catalyst precursor; (c) a treatment step in which the modified-catalyst precursor is treated with a mono or polychlorinated compound, thereby yielding the solid catalyst component; and (d) isolating and recovering the solid catalyst component.

The invention describes a method for dimerization of ethylene implementing a step for treatment of raw effluent by neutralization, at the outlet of the reactor, of the catalyst for dimerization of ethylene into but-1-ene by a particular alcohol.

The present invention relates to a process for the preparation of a catalyst for selective catalytic reduction comprising (i) preparing a mixture comprising a metal-organic framework material comprising an ion of a metal or metalloid selected from groups 2-5, groups 7-9, and groups 11-14 of the Periodic Table of the Elements, and at least one at least monodentate organic compound, a zeolitic material containing a metal as a non-framework element, optionally a solvent system, and optionally a pasting agent, (ii) calcining of the mixture obtained in (i); and further relates to a catalyst per se comprising a composite material containing an amorphous mesoporous metal and/or metalloid oxide and a zeolitic material, wherein the zeolitic material contains a metal as non-framework element, as well as to the use of said catalyst.