A catalyst for catalytic oxidation of furfural to prepare maleic acid, relating to the technical field of renewable energy. The catalyst is a mixture of a bromide and a base. A method for preparing the catalyst in catalytic oxidation of furfural to prepare maleic acid. The method includes: mixing the furfural, the bromide-base, an oxidant and a solvent to carry out a reaction to obtain the maleic acid. The present invention has the advantages that the method has a relatively high conversion rate of furfural and a relatively high yield of maleic acid, the conversion rate of furfural is up to 99%, the yield of maleic acid is up to 68.04%; and the catalyst has a high catalytic selectivity and reusability.

The present invention describes method of preparation of esters or amides of lactyl lactates of general formula I, where Z denotes to group of R—O or RR′—N and R represent alkyl, aryl or H from lactide and the lactide is in contact with a hydrocarbyl alcohol and a hydrolyzable halide in a non-chlorinated organic solvent, or an amine initiated by a hydrolysable halide or hydrogen halide solution or an ammonium hydrohalide, wherein the hydrocarbyl alcohol or amine is either aliphatic or aromatic and containing 1 to 1000 carbon atoms, preferably 1 up to 150 carbon atoms, and optionally one or more, preferably 1 to 5, —CH.sub.2— groups may be replaced by —O— groups.

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The present invention describes method of preparation of esters or amides of lactyl lactates of general formula I, where Z denotes to group of R—O or RR′—N and R represent alkyl, aryl or H from lactide and the lactide is in contact with a hydrocarbyl alcohol and a hydrolyzable halide in a non-chlorinated organic solvent, or an amine initiated by a hydrolysable halide or hydrogen halide solution or an ammonium hydrohalide, wherein the hydrocarbyl alcohol or amine is either aliphatic or aromatic and containing 1 to 1000 carbon atoms, preferably 1 up to 150 carbon atoms, and optionally one or more, preferably 1 to 5, —CH.sub.2— groups may be replaced by —O— groups.

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Nature is capable of storing solar energy in chemical bonds via photosynthesis through a series of C—C, C—O and C—N bond-forming reactions starting from CO.sub.2 and light. Direct capture of solar energy for organic synthesis is a promising approach. Lead (Pb)-halide perovskite solar cells reach 24.2% power conversion efficiency, rendering perovskite a unique type material for solar energy capture. We show that photophysical properties of perovskites is useful in photoredox organic synthesis. Because the key aspects of these two applications are both relying on charge separation and transfer. Here we demonstrated that perovskites nanocrystals are exceptional candidates as photocatalysts for fundamental organic reactions, i.e. C—C, C—N and C—O bond-formations. Stability of CsPbBr.sub.3 in organic solvents and ease-of-tuning their bandedges garner perovskite a wider scope of organic substrate activations.

The invention provides a process for the preparation of bismuth oxyhalide, comprising a precipitation of bismuth oxyhalide in an acidic aqueous medium in the presence of a reducing agent. Also provided are bismuth oxyhalide compounds doped with elemental bismuth Bi.sup.(0). The use of Bi.sup.(0)doped-bismuth oxyhalide as photocatalysts in water purification is also described.

The invention provides a process for the preparation of bismuth oxyhalide, comprising a precipitation of bismuth oxyhalide in an acidic aqueous medium in the presence of a reducing agent. Also provided are bismuth oxyhalide compounds doped with elemental bismuth Bi.sup.(0). The use of Bi.sup.(0)doped-bismuth oxyhalide as photocatalysts in water purification is also described.

A catalyst system, which is active in pyrolyzing methane at reaction temperatures above 700° C., comprising a molten salt selected from the group consisting of the halides of alkali metals; the halides of alkaline earth metals; the halides of zinc, copper, manganese, cadmium, tin and iron; and mixtures thereof, the molten salt having dispersed therein one or more catalytically active forms of iron, molybdenum, manganese, nickel, cobalt, zinc, titanium, and copper in the form of finely divided elemental metals, metal oxides, metal carbides or mixtures thereof.

A catalyst system, which is active in pyrolyzing methane at reaction temperatures above 700° C., comprising a molten salt selected from the group consisting of the halides of alkali metals; the halides of alkaline earth metals; the halides of zinc, copper, manganese, cadmium, tin and iron; and mixtures thereof, the molten salt having dispersed therein one or more catalytically active forms of iron, molybdenum, manganese, nickel, cobalt, zinc, titanium, and copper in the form of finely divided elemental metals, metal oxides, metal carbides or mixtures thereof.

Provided is a method capable of industrially efficiently producing acetic acid yielding a good potassium permanganate test result, without costing much. In the acetic acid production method, (1) by-produced acetaldehyde is industrially advantageously removed from a process stream, and (2) a crotonaldehyde concentration in an acetic acid stream from a light ends column is controlled to a specific level or lower, and/or a reflux ratio at a second distillation column is controlled to 0.1 or more. In addition, (3) the method includes the step of subjecting at least one of an aqueous phase and an organic phase of a light ends column overhead condensate to distillation in a crotonaldehyde-removing column; the light ends column is operated at a reflux ratio of 2 or more (when the aqueous phase is refluxed); and the crotonaldehyde-removing column is operated so as to meet a specific condition(s).

Provided is a method capable of industrially efficiently producing acetic acid yielding a good potassium permanganate test result, without costing much. In the acetic acid production method, (1) by-produced acetaldehyde is industrially advantageously removed from a process stream, and (2) a crotonaldehyde concentration in an acetic acid stream from a light ends column is controlled to a specific level or lower, and/or a reflux ratio at a second distillation column is controlled to 0.1 or more. In addition, (3) the method includes the step of subjecting at least one of an aqueous phase and an organic phase of a light ends column overhead condensate to distillation in a crotonaldehyde-removing column; the light ends column is operated at a reflux ratio of 2 or more (when the aqueous phase is refluxed); and the crotonaldehyde-removing column is operated so as to meet a specific condition(s).