▎ 摘　　要

NOVELTY - Preparing composite sulfate radical catalyst using liquid phase preparation method comprises (i) adding graphene oxide and hydrazine to a reaction kettle, ultrasonically dispersing, increasing the temperature to reaction temperature to carry out react, and obtaining graphene precipitate, washing the precipitate, adding water again, and ultrasonically dispersing to obtain graphene suspension, (ii) dropping sodium hydroxide into aluminum nitrate solution at temperature of 40-80°C to obtain liquid aluminum hydroxide, adding the aluminum hydroxide dissolved in water to graphene suspension under the stirring condition, embedding aluminum hydroxide is embedded graphene key, filtering, washing, and drying to obtain precursor aluminum-OGN (AL-OGN); (iii) adding the precursor into concentrated sulfuric acid combined with sulfate, and drying, and (iv) calcining to obtain sulfate/Al-O-GN solid acid. USE - Method for preparing composite sulfate radical catalyst using liquid phase preparation method, which is used for preparing biosaccharide (claimed). ADVANTAGE - The method increases the specific surface area of the solid acid catalyst; and improves the catalytic efficiency. The catalyst: is prepared by utilizing the liquid phase environment. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for the composite sulfate radical catalyst for biosaccharide prepared by the above-mentioned method.