Provided herein are a method of Ru(II)-catalyzed enantioselective synthesis of a cyclic compound and cyclic compounds formed therefrom. The method includes providing a precursor compound having an unfunctionalized C—H bond and activating the unfunctionalized C—H bond by reacting the precursor compound in the presence of co-catalysts including a Ru(II) arene complex and a chiral transient directing group (CTDG).

Disclosed are a method and an apparatus for preparing an alkylene carbonate using a polyamine-based heterogeneous catalyst. The rapid increase in reactor temperature and the risk of explosion due to heat of reaction may be prevented by recycling the produced alkylene carbonate to the reactor. Accordingly, it is possible to obtain the alkylene carbonate stably and continuously with high yield while maintaining reaction temperature and pressure constant.

The present disclosure provides a catalyst for reducing CO and HC which is a core-shell particle including a core and a shell surrounding the core, the core includes metal oxide nanoparticles and noble metal nanoparticles fixed to the metal oxide nanoparticles, and the shell includes zirconia (ZrO.sub.2), and a layer from which the metal oxide is removed between the core and the shell is included.

According to one embodiment, a catalyst system that reduces polymeric fouling may include at least one chromium compound, at least one aluminum compound, and at least one antifouling agent or a derivative thereof. The antifouling agent may have a structure including a central aluminum molecule bound to an R1 group, bound to an R2 group, and bound to an R3 group. One or more of the chemical groups R1, R2, and R3 may be antifouling groups having the structure —O((CH.sub.2).sub.nO).sub.mR4, a phosphonium or phosphonium salt, a sulfonate or sulfonate salt, a sulfonium or sulfonium salt, an ester, an anhydride, a polyether, or a long-chained amine-capped compound, where n is an integer from 1 to 20, m is an integer from 1 to 100, and R4 is a hydrocarbyl group. The chemical groups R1, R2, or R3 that do not include an antifouling group, if any, may be hydrocarbyl groups.

A compound having the formula (I): ##STR00001##
is disclosed. A method of preparing the compound of formula (I) is also disclosed.

The present disclosure provides a Lewis acid-base pair catalytic initiator and an application thereof. The Lewis acid-base pair catalytic initiator includes a Lewis acid and a Lewis base, the Lewis acid having a structural general formula as shown in formula (I) and the Lewis base having a structural general formula as shown in formula (II); wherein: the A is selected from element Baron or element Aluminum; the R.sub.1, R.sub.2, R.sub.3, R.sub.4 are independently selected from alkyl, alkoxy, aryl or halogen groups; the alkyl or alkoxy have a carbon number being equal to or greater than 1 to equal to or less than 16; the aryl contains substituents with the number being equal to or less than 5, the substituents being selected from methyl, methoxy or halogen; n is selected from an integer from 1 to 16.

The present invention discloses a selective hydrogenation catalyst and a preparation method and an application thereof, belonging to the technical field of catalysts. The selective hydrogenation catalyst comprises an active component and a carrier for supporting the active component, wherein the active component is a transition metal particle, the carrier is modified by a flexible chain ligand in advance, one end of the flexible chain ligand is uniformly distributed on the surface of the carrier, and the other end of the flexible chain ligand is coordinated on a transition metal. When the catalyst is used for catalytic hydrogenation reaction of dehydrolinalool or 2-methyl-3-butyn-2-ol, the stability is good, the catalyst still has high selectivity after being used for a long time, and the quality of a hydrogenation product can be guaranteed.

The present invention discloses a selective hydrogenation catalyst and a preparation method and an application thereof, belonging to the technical field of catalysts. The selective hydrogenation catalyst comprises an active component and a carrier for supporting the active component, wherein the active component is a transition metal particle, the carrier is modified by a flexible chain ligand in advance, one end of the flexible chain ligand is uniformly distributed on the surface of the carrier, and the other end of the flexible chain ligand is coordinated on a transition metal. When the catalyst is used for catalytic hydrogenation reaction of dehydrolinalool or 2-methyl-3-butyn-2-ol, the stability is good, the catalyst still has high selectivity after being used for a long time, and the quality of a hydrogenation product can be guaranteed.

The present disclosure relates to a preparation method of an acrylic ester compound. The preparation method of an acrylic ester compound according to the present disclosure enables the use of acrylic anhydride as a reactant instead of acryloyl chloride, which is difficult to handle, by using an alkane diamine as a catalyst. Therefore, not only can the reaction be carried out at a low temperature, but also conversion to an acrylic ester compound and a yield of the acrylic ester compound can be improved.

A process for preparing an oligomerization catalyst is based on using nickel aluminosilicate that has high activity and selectivity coupled with adequate service life in the heterogeneously catalysed oligomerization of C3 to C6 olefins or olefin-containing feed mixtures based thereon.