Alum is a term commonly used to refer to a class of double sulfate salts, primarily composed of aluminum sulfate and the sulfate of another element such as potassium, sodium, or ammonium. Potassium alum (KAl(SO4)2·12H2O) is one of the most well-known forms. Alums are widely used in various industrial and scientific applications due to their unique properties, including in the field of catalysis.
