Catalysts and methods for making cyclic carbonates are disclosed. The catalyst may include at least one polymer quaternary ammonium salt, at least one metal halide and silica gel. The method of making the cyclic carbonates may include forming a mixture that includes the catalyst and an epoxide, and contacting the mixture with carbon dioxide in a reactor under conditions to form the propylene carbonate.

The present invention relates to hydrogen peroxide manufacturing process and manufacturing system based on a photochemical reaction. Specifically, the present invention relates to a series of hydrogen peroxide manufacturing processes of generating, extracting, and purifying hydrogen peroxide through a photochemical reaction, and a hydrogen peroxide manufacturing system which is applied with the manufacturing processes and consists of a photoreactor-extractor-purifier.