Provided are a novel indene-based transition metal complex, a transition metal catalyst composition including the same having high catalyst activity for preparing an ethylene homopolymer or copolymers of ethylene and one or more -olefins, a method for preparing an ethylene homopolymer or copolymers of ethylene and -olefins using the same, and the thus-prepared ethylene homopolymer or copolymers of ethylene and -olefins.

A method for producing an -olefin oligomer, the method including subjecting -olefin to oligomerization reaction to produce an -olefin oligomer mixture, carrying out distillation separation of -olefin oligomer having less than n carbon atoms in the mixture to obtain a distillation residue containing -olefin oligomer having n or more carbon atoms, and then carrying out a step of removing high molecular weight molecules from the distillation residue.

The present invention relates to a composite catalyst, preparation process thereof, and process for catalyzing the trimerization of butadiene using the composite catalyst. The composite catalyst comprises: (A) a titanium compound catalyst active component, (B) an organometallic compound co-catalyst component, (C) a sulfoxide compound catalyst-modifying component, (D) a monoester compound catalyst-modifying component, and (E) a solvent component. The composite catalyst has advantages of excellent selectivity, high catalytic activity, easy preparation and so on.

A method for processing an oligomerization product stream includes discharging the oligomerization product stream from an oligomerization reactor through a product outlet line, and heating the oligomerization product stream, heating a wall of the product outlet line, or both. The oligomerization product stream includes solvent, linear alpha olefins, a polymer byproduct, or a combination of at least one of the foregoing. The heating is to a temperature that is greater than the melting temperature of the polymer byproduct present in the oligomerization product stream.

The present invention discloses a composite catalyst for the photocatalytic isomerization of norbornadiene to prepare quadricyclane, comprising: a solid photocatalyst, selected from the group consisting of TiO.sub.2, Ti-MCM-41, Ti-SBA-15, ZnO, WO.sub.3, Ta.sub.2O.sub.5 or SrTiO.sub.3; and an organic photo-sensitizer loaded on the surface or in the channel of said solid photocatalyst, selected from benzophenone, acetophenone, Michler's Ketone, tetraethyl Michler's Ketone, and diethyl Michler's Ketone, where the organic photo-sensitizer is present in the solid photocatalyst in an amount of 0.5% to 20% by weight. The catalyst of the invention can catalyze a target reaction under the condition that no solvent is used, and the yield of the target product quadricyclane is higher. Furthermore, the catalyst of the invention has a stable activity, and it can be recycled. The invention further discloses a process for preparing the composite catalyst.

The invention discloses a continuous process for producing high-pure quadricyclane, in which a reaction-rectification integral process or a reaction followed by rectification process may be employed. The two processes both use a novel composite catalyst which is obtained by loading an organic photo-sensitizer on a solid photocatalyst, and the composite catalyst has a high activity and a good stability. In the reaction-rectification integral process, the composite catalyst is used by being blended with rectification fillers or covering the rectification fillers, so as to achieve the integration of the reaction and the rectification. In the reaction followed by rectification process, the composite catalyst and the rectification fillers are placed separately from each other. The two processes achieve a relatively short residence time of reactants, produce highly-pure quadricyclane, and reduce the formation of cokes.

Methods and systems for selectively hydrogenating benzene with a supported organometallic hydrogenating catalyst are provided. An exemplary method includes contacting an arene-containing reaction stream comprising benzene and one or more additional arenes with hydrogen in the presence of a supported organometallic hydrogenating catalyst under reaction conditions effective to hydrogenate at least benzene in the arene-containing reaction stream to produce a reaction effluent having a ratio of benzene to additional arenes that is lower than a ratio of benzene to additional arenes in the reaction stream. In this method, the supported organometallic hydrogenating catalyst includes a catalytically active organometallic species and a Brnsted acidic sulfated metal oxide support.

The present invention relates to methods of employing a metal-organic framework (MOF) as a catalyst for cleaving chemical bonds. In particular instances, the MOF results in selective bond cleavage that results in hydrogenolyzis. Furthermore, the MOF catalyst can be reused in multiple cycles. Such MOF-based catalysts can be useful, e.g., to convert biomass components.

Catalyst system for producing ethylene copolymers in a high temperature solution process, the catalyst system comprising (i) a metallocene complex of formula (I) wherein M is Hf X is a sigma ligand, L is a bridge of the formula SiR.sup.8.sub.2, wherein each R.sup.8 is independently a C.sub.1-C.sub.20-hydrocarbyl, tri(C.sub.1-C.sub.20-alkyl)silyl, C.sub.6-C.sub.20-aryl, C.sub.7-C.sub.20-arylalkyl or C.sub.7-C.sub.20-alkylaryl n is 0, 1 or 2 R.sup.1 and R.sup.1 are the same or can be different and can be a linear or branched C.sub.1-C.sub.6-alkyl group, R.sup.2 and R.sup.2 are the same or are different and are a CH.sub.2R.sup.9 group, with R.sup.9 being H or linear or branched C.sub.1-C.sub.6-alkyl group R.sup.5 and R.sup.5 are the same or are different and can be H or a linear or branched C.sub.1-C.sub.6-alkyl group or a OR group, wherein R is a C.sub.1-C.sub.6-alkyl group R.sup.6 and R.sup.6 are the same or are different and can be H or a C(R.sup.10).sub.3 group, with R.sup.10 being the same or different and R.sup.10 can be H or a linear or branched C.sub.1-C.sub.6-alkyl group or R.sup.5 and R.sup.6 and/or R.sup.5 and R.sup.6 taken together form an unsubstituted 4-7 membered ring condensed to the benzene ring of the indenyl moiety, and R.sup.7 and R.sup.7 can be the same or are different and can be H or a linear or branched C.sub.1-C.sub.6-alkyl group (ii) an aluminoxane cocatalyst and/or (iii) a boron containing cocatalyst and (iv) optionally an aluminium alkyl compound.

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