Solid acid catalyst

A method for preparing a solid acid catalyst having the following structure (A), structure (B) and metal atom (C);

• Structure (A):
• a structure in which a hydrogen atom is eliminated from at least one of OH groups contained in an inorganic phosphorus acid;
• Structure (B):
• a structure in which a hydrogen atom is eliminated from at least one of OH groups contained in an organic groups contained in an organic phosphorus acid represented by the formula (1) or (2):
• wherein each of —R1 and R2 is selected from —R, —OR, —OH and —H in which at least one of —R1 and —R2 is —R or —OR, given that —R is an organic group having 1 to 22 carbon atoms;
• Metal atom (C):
• at least one atom selected from aluminum, gallium and iron,
• comprising precipitating said solid acid catalyst from an aqueous solution of water-soluble metal salt, inorganic phosphorous acid and organic phosphorus acid, with alkali.

A method for preparing a solid acid catalyst having the following structure (A), structure (B) and metal atom (C);

• Structure (A):
• a structure in which a hydrogen atom is eliminated from at least one of OH groups contained in an inorganic phosphorus acid;
• Structure (B):
• a structure in which a hydrogen atom is eliminated from at least one of OH groups contained in an organic groups contained in an organic phosphorus acid represented by the formula (1) or (2):
• wherein each of —R1 and R2 is selected from —R, —OR, —OH and —H in which at least one of —R1 and —R2 is —R or —OR, given that —R is an organic group having 1 to 22 carbon atoms;
• Metal atom (C):
• at least one atom selected from aluminum, gallium and iron,
• comprising impregnating an inorganic phosphorous acid and an organic phosphorus acid onto a metal oxide or a metal hydroxide.

A method for preparing a solid acid catalyst having the following structure (A), structure (B) and metal atom (C);

• Structure (A):
• a structure in which a hydrogen atom is eliminated from at least one of OH groups contained in an inorganic phosphorus acid;
• Structure (B):
• a structure in which a hydrogen atom is eliminated from at least one of OH groups contained in an organic groups contained in an organic phosphorus acid represented by the formula (1) or (2):
• wherein each of —R1 and R2 is selected from —R, —OR, —OH and —H in which at least one of —R1 and —R2 is —R or —OR, given that —R is an organic group having 1 to 22 carbon atoms;
• Metal atom (C):
• at least one atom selected from aluminum, gallium and iron,
• comprising substituting an inorganic phosphorous acid group in an inorganic phosphorus acid metal salt-gel for an organic phosphorus acid group.