The present invention relates to a transition metal-based heterogeneous carbonylation reaction catalyst that has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction; and a method for preparing lactone using the same. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

The present invention relates to an organic zinc catalyst which exhibits more improved catalytic activity than conventional organic zinc catalysts during a polymerization process for the preparation of a polyalkylene carbonate resin and is capable of preventing an aggregation phenomenon during a reaction, a method for preparing the same, and a method for preparing a polyalkylene carbonate resin using the organic zinc catalyst. The method for preparing an organic zinc catalyst includes the step of reacting a zinc precursor with a dicarboxylic acid in the presence of a polyether derivative to form a zinc dicarboxylate-based catalyst.

The present invention relates to an organic zinc catalyst which exhibits more improved catalytic activity than conventional organic zinc catalysts during a polymerization process for the preparation of a polyalkylene carbonate resin and is capable of preventing an aggregation phenomenon during a reaction, a method for preparing the same, and a method for preparing a polyalkylene carbonate resin using the organic zinc catalyst. The method for preparing an organic zinc catalyst includes the step of reacting a zinc precursor with a dicarboxylic acid in the presence of a polyether derivative to form a zinc dicarboxylate-based catalyst.

A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.

A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.

Provided herein are processes for the preparation of heteroaryl carboxylic acids.

Provided herein are processes for the preparation of heteroaryl carboxylic acids.

A method of synthesizing three-dimensional (3D) reduced graphene oxide (RGO) foams embedded with water splitting nanocatalysts includes providing a first solution containing nickel (II) nitrate, a second solution containing iron (III) nitrate, and a graphene oxide (GO) aqueous suspension; mixing the GO aqueous suspension with the first solution and the second solution to form a GO-NiFe mixture; adjusting a pH value of the GO-NiFe mixture to be about 3.5; and performing hydrothermal reaction in the GO-NiFe mixture to form RGO-NiFe foams, wherein nanocatalysts containing Ni-Fi oxide particles are embedded in porous structures of the 3D RGO foams.

A method of synthesizing three-dimensional (3D) reduced graphene oxide (RGO) foams embedded with water splitting nanocatalysts includes providing a first solution containing nickel (II) nitrate, a second solution containing iron (III) nitrate, and a graphene oxide (GO) aqueous suspension; mixing the GO aqueous suspension with the first solution and the second solution to form a GO-NiFe mixture; adjusting a pH value of the GO-NiFe mixture to be about 3.5; and performing hydrothermal reaction in the GO-NiFe mixture to form RGO-NiFe foams, wherein nanocatalysts containing Ni-Fi oxide particles are embedded in porous structures of the 3D RGO foams.

The present invention relates to a catalytic composition comprising at least 7 different elements selected from the group consisting of the elements defined by the intersection of the second to the sixth period and the first to the sixteenth group of the periodic table of the elements, whereby technetium is excluded, and a matrix component. A method for use of the catalytic composition is also provided.