Abstract: Agglomerates of zeolitic molecular sieves which are bonded with particles of generally spherical amorphous colloidal-sized silica particles having nominal diameters in the range of 40 to 800 nanometers are found to have increased adsorption capacity for many molecular species due to the development in the binder of a pore system created by the packing of the silica spheres. When the molecular sieves employed are highly siliceous and hydrophobic, the agglomerates are ideally suited for use in odor elimination applications in which unagglomerated molecular sieve particles create dusting and handling problems.