Inorganic Materials monolithic alveolar cationic exchangers, their process for the preparation, separation and method of implementing them.

solid material in the form of a honeycomb monolith constituted by a calcined matrix of an inorganic oxide with a hierarchical porosity and open comprising macropores, mesopores, and micropores, defined by walls, with atoms of a metal integrated M transition and related to said walls, said macropores, mesopores and micropores being interconnected, wherein nanoparticles of an inorganic solid material exchanger of a metal cation selected from hexa- and metal octacyanometallates are distributed in said porosity, and the nanoparticles are attached to an inner surface of said walls through said transition metal atom M. a method for preparing said material. A method for separating at least one metal cation such as radioactive cesium from a liquid medium container, wherein comprises contacting said liquid medium with said material.