Carbon-based solid acid catalyst, preparation method of catalyst, and application to hydrothermal conversion of biomass

A method for preparation of a carbon-based solid acid catalyst, comprising:

• S1) mixing a pectin and an ionic resin with an aromatic ring matrix in a medium to obtain a first resulting mixture, wherein the pectin is used as a carbon-based precursor, wherein S1 comprises:
• mixing the pectin with water in a mass ratio of 1:(4-10), adding sulfuric acid for an activation to obtain a second resulting mixture, and adding the second resulting mixture to the ionic resin with the aromatic ring matrix to obtain the first resulting mixture, wherein a mass ratio of the ionic resin to the pectin is 1:(0.5-3);
• S2) drying the first resulting mixture obtained in S1 to obtain a dried black material, crushing the dried black material into a powder, and subjecting the powder to a pyrolysis for 0.5 h to 3 h in a dry inert gas to obtain a solid;
• S3) subjecting the solid obtained after the pyrolysis in S2 to a sulfonation with concentrated sulfuric acid at 20° C. to 120° C. to obtain a material;
• S4) diluting the material obtained in S3 with water to obtain a third resulting mixture, filtering the third resulting mixture to obtain a resulting filter residue, and washing the resulting filter residue with water until no sulfate ions are detected in washing water;
• and
• S5) oven-drying the resulting filter residue to obtain the carbon-based solid acid catalyst.