A mesostructured material that consists of at least two elementary spherical particles, each of said particles comprising a mesostructured matrix based on aluminum oxide and having a pore size of between 1.5 and 30 nm, an aluminum oxide content that represents more than 46% by weight relative to the mass of said matrix, which has amorphous walls with a thickness of between 1 and 30 nm and whereby said elementary spherical particles have a maximum diameter of 10 μm, is described. Said mesostructured matrix can also contain silicon oxide. Each of the spherical particles of the mesostructured material can also contain zeolitic nanocrystals so as to form a material with a mixed porosity that is both mesostructured and zeolitic in nature. The preparation of said material is also described.