A method for improving the stability of a catalyst in recycling HFC-23 is provided. The recycling is realized by means of a fluorine-chlorine exchange reaction with HFC-23 and a halogenated hydrocarbon. The catalyst for the fluorine-chlorine exchange reaction comprises a main body catalyst and a metal oxide, wherein the metal oxide is selected from at least one metal oxide of K, Na, Fe, Co, Cu, Ni, Zn or Ti, and has an addition amount of 0.1-5 wt %. The method has advantages such as a good catalyst stability, a long life, and a low content of by-product CFC-12.

Minimum-boiling, heterogeneous azeotropic and azeotrope-like compositions including 1,1,2,2,3-pentachloropropane (HCC-240aa) and hydrogen fluoride (HF), as well as methods for using these azeotropic or azeotrope-like compositions in the production of trifluorochloropropenes.

Minimum-boiling, heterogeneous azeotropic and azeotrope-like compositions including 1,1,2,2,3-pentachloropropane (HCC-240aa) and hydrogen fluoride (HF), as well as methods for using these azeotropic or azeotrope-like compositions in the production of trifluorochloropropenes.

Proposed is a photocatalytic complex. The photocatalytic complex includes a photocatalyst, and an iodine compound layer formed on a surface of the photocatalyst to cover the same and containing an iodine compound. The present disclosure enables selective degradation of hydrophilic volatile organic compounds by the use of the photocatalyst coated with the iodine compound.

Proposed is a photocatalytic complex. The photocatalytic complex includes a photocatalyst, and an iodine compound layer formed on a surface of the photocatalyst to cover the same and containing an iodine compound. The present disclosure enables selective degradation of hydrophilic volatile organic compounds by the use of the photocatalyst coated with the iodine compound.